Mobilising Migrants Making Citizens: Migrant Domestic Workers as

Keywords: Citizenship, Domestic Work, trafficking, immigration policy, labour migrants, Mobilization migration, domestic workers, citizenship, trafficking, illegality, trades unions

It is now more important than ever to consider migrant mobilizations and how political communities are constructed. This paper describes how Waling Waling, a migrant domestic workers' organization, and their support group, Kalayaan, forged citizenship 'from below' and waged a successful campaign to change the immigration status of domestic workers in part through turning constraints into opportunities. It also discusses how the logic of state sovereignty can recapture radical takings, and the opportunities and challenges that are faced in the new political climate of migrants as victims of trafficking.

months passed and the numbers increased the structural nature of the problem became clear: the workers had been allowed into the UK only on the basis that they were working for the employer they entered with. If they left that employer they had no permission to work in the UK and were effectively forced into illegality.

It became increasingly difficult to respond to their needs on a case by case basis, and in November 1984 CFMW set up a meeting attended by seventeen domestic workers and ten supporters with the purpose of sharing their experiences and discussing a way forward. This grouping became formalized as 'Waling Waling', a Tagalog word for a flower that grows hidden under stones in the mountains of the Philippines. Thus began many years of organizing and campaigning for the right to an immigration status that recognised domestic workers as workers, the right to change employer, and the right to legal status for those who had become undocumented as a result of the injustice of the immigration regime.

Using this example as a case study this paper will consider how migrant domestic workers, working with supporters (both UK and non UK citizens with status) asserted citizenship claims and won legal status in part through turning their constraints (as women 'confined' to the private sphere) into opportunities. I will also examine how 'radical takings can nevertheless be captured by the logic and practices of state sovereignity' [START_REF] Nyers | Abject Cosmopolitanism: the politics of protection in the anti-deportation movement[END_REF] through a consideration of post campaigning developments. The practicalities: organising for rights

These migrants had all entered the UK as domestic workers accompanying wealthy employers. These included business people and executives, diplomats, rich tourists, and UK residents returning from abroad with their domestic staff. When work permits for resident domestic workers were phased out in 1979 the government made exceptions for those accompanying wealth employers. This was on the grounds of 'national interest', concerned that If wealth investors, skilled workers and others with the potential to benefit our economy were unable to be accompanied by their domestic staff they might not come here at all (Lord Reay speaking in House of Lords debate on overseas domestic workers, 28 th November 1990. Hansard col. 1052).

The UK government seems to have regarded this category of worker as an unfortunate necessity and in this case specifically devised a concession under which the employer could bring in their worker under one of two categories, as 'visitors' or as 'persons named to work with a specified employer'. In practice there was a 'concession culture' under which domestic workers accompanying their employers were admitted to the UK with a wide variety of visas and many were given a stamp under Code 5N, namely 'Leave to enter, employment prohibited'. So, these workers had all entered the UK legally accompanying wealthy employers as their cooks, cleaners, nannies, and carers, but they had not been given an immigration status independent of their employers. This meant that employers could effectively exploit and abuse domestic workers with impunity. [START_REF] Anderson | Doing the Dirty Work? The global politics of domestic labour[END_REF].

In the meeting organised that cold November night in 1984 the group recognized their common experiences and decided to continue to see each other to facilitate mutual support. It grew quickly. Workers supported each other psychologically and also met the immediate needs of those who had recently escaped from employers, often with only the clothes that they were wearing. As time went by and they grew in confidence workers began to organise events and trips, concerned that members should be leading as 'normal' a life as possible, whatever their immigration status. This work was affective as well as practical, and as affective work was crucial to the formation of a political community [START_REF] Isin | Being Political: Genealogies of Citizenship[END_REF]. What was particularly innovative about Waling Waling was that they did not organize around country of origin, but type of employment and immigration status While in recent years this kind of organizing has proliferated [START_REF] Laubenthal | The Emergence of Pro-Regularization Movements in Western Europe[END_REF] In recent years there has been an increasing interest in the philosophy, politics and practice of citizenship. Those interested in immigration and asylum, have drawn attention to the 'inward-looking' framework of some of this literature, its assumption of a universalist ethic, that citizenship means 'everyone' [START_REF] Bosniak | The Citizen and the Alien: dilemmas of contemporary membership[END_REF]. Bosniak argues that this is 'romantic'

The idea of citizenship is commonly invoked to convey a state of democratic belonging or inclusion, yet this inclusion is usually premised on a conception of a community that is bounded and exclusive. Citizenship as an ideal is understood to embody a commitment against subordination, but citizenship can also represent an axis of subordination itself'

(2006: 1) Citizenship, while epitomising rights and inclusion, also works to exclude and deprive, as those working practically and theoretically with migrants and refugees are all too aware.

There have been attempts to bridge this gap, by understanding citizenship not as simply a legal status bestowed by the state 1 , but also as the creation and engagement with polity, [START_REF] Balibar | We, the People of Europe? Reflections on transnational citizenship[END_REF]). Thus it is not simply a legal status bestowed by the state, but actively constructed through action and through participation in the public. As Balibar puts it:

We can view these demands (by migrant workers who demand legal residence for the undocumented) based on resistance and the refusal of violence as partial but direct expressions of the process of creation of rights, a dynamic that allows the political constitution to be recognized as 'popular sovereignty' or democracy [START_REF] Balibar | We, the People of Europe? Reflections on transnational citizenship[END_REF] This views citizenship as a process of constructing relations, in which all can be directly engaged including those who are formally excluded from the polity. As undocumented migrants demand rights, through public campaigning and negotiation, so they actively make citizenship. They are not simply passive recipients of citizenship, but in rejecting the state's denial of rights, effectively forge them as a collective project. The assertion of oneself as a political actor is an act of 'dissensus', highlighting the contradictions between the 'Rights of Man' and the positions of those who are refused recognition of political subjecthood (Rancière 2004).

Not all non-citizens are however equally excluded. Balibar has described borders as 'polysemic' [START_REF] Balibar | Politics and the Other Scene[END_REF] in that they have a differential impact on those crossing them. In this case, the wealthy employers of domestic workers were acknowledged by the British state in their capacity as visitors or business people and were granted the normal protections against crime for example -so if an employer complained that a domestic worker had stolen from them, the police would investigate the theft. This did not apply to domestic workers, who had no protection against for example their employer holding their passport, or refusing to political speech [START_REF] Nyers | Abject Cosmopolitanism: the politics of protection in the anti-deportation movement[END_REF] and in this case, the first political act of political speech was to each other Before, when I was alone, I didn't trust anyone. … When I began to talk to people in similar situations and I saw that I was not alone, I realized that the problem was not just to do with me, that it was the Philippines and Britain and the government in those countries. [START_REF] Anderson | Britain's Secret Slaves: migrant domestic workers in the UK[END_REF] Speaking to each other, 'coming out' about legal status, meant that domestic workers began to feel less isolated and divided from others.

Workers and Citizens

A key feature of organizing and campaigning was Waling Waling's demand to be recognized as workers. This assertion, that they were workers, worked on several levels. Firstly it asserted the dignity and value of their work, for themselves, employers and the wider public. They were not 'helping' but contributing socially and economically to households and wider society; they were not 'girls' but women (and men) who were often sustaining extended families back home. It also asserted their legitimacy as public actors, their right to be heard and to be treated with respect, and it was accompanied by the demand that this labour be recognized as a route to formalized citizenship. The claim that migrant domestic workers were workers built on the slave/worker binary, (1995, Slavery Still Alive was the title of one conference organized). Migrants asserted their claim that they were not slaves but workers, and used this assertion to demand a suitable immigration status, one that recognized their right to work. It is important to recognize that this move, from worker to citizen, is not straightforward [START_REF] Gordon | Rethinking Work and Citizenship[END_REF] (2003:7). There is evidence that these processes were at work in the relatively sympathetic public response to the situation of domestic workers. The campaign often found itself working against strongly gendered and racialized images of the abused domestic worker and the abusive (male) employer. This notion -of evil foreigners importing slavery, of the importance of the triumph of British values of freedom and democracy -were expressed at all levels, by supportive MPs as well as the tabloid press [START_REF] Anderson | Doing the Dirty Work? The global politics of domestic labour[END_REF]. In rescuing her from the clutches of the employer, the UK was portrayed as re-enacting its status as an upholder of justice and liberty. The 'good' migrant contains the 'bad', the victim has a parallel villain, the UK may accept the domestic work, but will extirpate the employer (rarely portrayed as British, or indeed white). While this forging of citizenship through political speech was a real achievement, one must not forget however the importance of formalized legal status [START_REF] Bosniak | The Citizen and the Alien: dilemmas of contemporary membership[END_REF]) -this is after all Waling Waling (and many other groups still) were demanding. Being recognised as a political actors in themselves was not itself the fulfilment of the demands even when this was acknowledged by civil society. This highlights a deep contradiction in many regularization movements: at the same time as challenging the authority of the state to 'illegalize', they are demanding 'legalization', that is a re-drawing of boundaries to include a new group of people. This redrawing inevitably excludes for it is not the abolition of boundaries all together. The power of the state to draw boundaries and exclude is reinscribed at the moment that it responds to the challenge. In this case, when, in 1997 the Home Office announced it was to bring domestic workers under the immigration rules, they invited Kalayaan and Waling

Waling to assist in drafting the new immigration rule. There was considerable discussion about this, but the argument that it was important to ensure the rule was as good as it could be, as long as that did not constrain criticism of it, won in the end.

Regularization and its discontents

In 1997 the incoming Labour administration gave migrant domestic workers the right to change employers and put them under the Immigration Rules (rather than a special 'concession'). It also offered the opportunity for regularization of those who had entered under the old system. This was expressed as a humanitarian response rather than a victory following many years of organizing and campaigning. However, despite the significance of this victory there were also ways in which it was 're-taken' by the state.

The regularization exercise was enacted individually on a 'case by case' basis with each case judged according to its 'merits'. Moreover this regularization was a 'special exercise' i.e. not under legal jurisdiction.

This meant operational definitions were not open to legal challenges and it was extremely difficult to appeal in those cases where people were refused. At first sight the requirements for 'straightforward cases' seemed relatively simple: a valid passport; proof that one currently is employed as a domestic worker and able to support and maintain oneself without recourse to public funds (a letter from the employer stating salary details and other 'in kind' payments); and proof that one entered as a domestic worker. Supporting documents, together with a standard application form for variation of leave to remain, and a photograph were to be sent to the Home Office. Obtaining these 'simple' requirements was often far from straightforward. Migrant domestic workers typically had their passports taken by their employer, while of those who had their passports, it was not unusual for people to have been in the UK for many years and their documents expired. Holding a valid passport usually meant reporting it lost or stolen to the police and then applying to an embassy or consulate for replacement documents. While many had no difficulty with this -the Philippines Consulate was particularly sympathetic -there were real problems with particular countries and officials especially for those whose original employers were diplomats, working in those same embassies.

One man went to his Embassy and found that it was his former, abusive employer who was responsible for issuing him his replacement passport.

'It is not stolen, I am holding it' the employer announced, refusing to give him another one. The worker could not apply for regularization.

The requirement that workers should not have recourse to public funds suggests that the regularization was not as 'humanitarian' as was made out to be. Those too old or sick to work, or who were unemployed did not qualify. Letters confirming employment from a current employer were accepted as proof, but employers were often extremely reluctant to offer them as they were concerned about being implicated in an immigration offence. Such was their resistance that the Home Office was eventually forced to give a reassurance that employer sanctions were never envisaged as intended for private households, in order that Kalayaan could encourage employers to support applications. This is not the same as tying a worker to an employer. Indeed some domestic workers made full use of the freedom to change employer offered by illegality to find people prepared to write letters. However, ironically what this requirement did was to reinscribe dependence on the employer as a gateway to status. The last requirement, proof of entry as a domestic worker, was particularly difficult. The government was anxious to limit access to the regularization, to re-draw the boundary in such a way that while this group was incorporated its members did not bring less deserving others with them. As the regularization progressed it became clear that under the 'concession culture' certain nationalities were more likely to be granted certain visas. For example domestic workers from many African countries were particularly likely to be given visas to enter as family members, while those from the Philippines were more likely to be given a visa with the name of the employer written in it. There is no suggestion that this reflected any immigration guidance, merely that this was the education, and were it not for their employer, would not have considered international migration. These sorts of differences mapped on to a labour market that is highly racialized [START_REF] Anderson | A Very Private Business: Exploring the Demand for Migrant Domestic Workers[END_REF][START_REF] Cox | The Servant Problem: Domestic Employment in a Global Economy[END_REF]. At that time employers were particularly interested in employing Filipino workers, meaning that Filipinos were more likely to find jobs and were more likely to be able to find an employer who was prepared to write a letter of support.

Regularization proceeded on a case by case basis, and in facilitating individuals' applications, Kalayaan became more and more orientated to a service rather than a campaigning role. This was also against a changing political, social and institutional background including the professionalization of advice work that regulated the previously unregulated world of immigration advice. The relation between the organizations began to shift as Waling Waling members became 'clients'.

Just after regularization was announced, Waling Waling was attracting between 200-300 people to its Sunday meetings. But members began to prioritise their own cases, to organize visits home and bring families to join them in the UK. There was some discussion in both organizations, about possible future organising and campaign work, a switch of focus perhaps to work related rights in private households, or on other types of immigration status that incorporate domestic workers, but there was little appetite for this, particularly as so many workers wanted to spend time with families that they had long been separated from. Thus in some ways the strength of the campaign -its relentless focus on immigration status, (Home Office 2007a)

A lack of definitional clarity allows a constant slippage between 'illegal migration' and 'trafficking'. This is not reflected even in the problematic international definition of the Palermo Protocol: migration does not have to be 'illegal' nor indeed across international borders, to constitute trafficking [START_REF] Gallagher | Human rights and the New UN Protocols on Trafficking and Migrant Smuggling: A Preliminary Analysis[END_REF]). This slippage is however rhetorical This implies that if the abuse is not taking place on UK territory, but is detected through pre-entry procedures, preventing entry is a sufficient response. In practise, the idea of refusing entry to employers and their domestic workers on the grounds that the employers were abusive would mean that they are likely to return to a state where the employer has a great deal of power over their worker. The refusal of entry to the UK would be unlikely to make them more sympathetic to their employee, and indeed could have catastrophic consequences.

When people do become victims, the state's responsibility to extend assistance is acknowledged. In this view, trafficked domestic workers are the victims of bad employers. In the cases where these bad employers manage to gain entry to the UK and commit abuses in the UK, the government will extend some protections to the victims. The appeal against trafficking seemed to have some leverage, and in the autumn of 2008 the government announced that it would not proceed with its proposals for at least two years and until it had conducted an assessment. However, while successful there are also dangers in attempts to 'retake' such state constructions. The language of trafficking is diametrically opposed to the ideas of citizenship as a process of constructing rights and relations, for it focuses on victimhood and on those who are unable to act for themselves. To pass the 'test' of trafficking one must be a true victim: injured, suffering and enslaved, an object of intervention rather than a political subject. To pass the test of trafficking one must be a true victim: unable to engage or make choices, only suffer and be rescued (Rancière 2004;[START_REF] Davidson | Will the Real Sex Slave Please Stand Up?[END_REF]).

Certainly the victim of trafficking cannot simply leave her employer, she must be physically imprisoned and make a dangerous escape, or she Trafficking risks sucking out the politics of citizenship. On the one hand the importance of formal citizenship/legal status and the role of the state in constructing vulnerability through denial of legal status is obscured by reference to 'human rights' denied by individual actors. Yet neither does it allow for citizenship as a process that migrants are actively engaged in. So political conflict is turned into negotiated adjustments of interests, patching over contradictions, where negotiation and patching is not being done by migrants. Indeed, migrants must compete for the role of who is the most victimised, the most exploited.

Conclusion

It would seem then from this case that it is easy for the state to incorporate radical politics and that attempts to subvert state rhetoric come at a price. However, while critiquing these processes one should not underestimate these achievements. The regularization and

  . The members of Waling Waling were not just excluded from the political by their 'illegal' immigration status, but also by virtue of their work. The household is the place for private individuals, not political, nor indeed market actors[START_REF] Anderson | A Very Private Business: Exploring the Demand for Migrant Domestic Workers[END_REF][START_REF] Olsen | The Family and the Market: a study of ideology and legal reform[END_REF] Pateman 1988).These two exclusionary frameworks worked together: citizenship/foreigner, public/private. Domestic workers were effectively consigned to the private, allowed entry to the UK only on the condition that they remained within the employer's household space. When they left their first employer they almost all continued to work in private homes as live-in domestic workers partly as a means of protecting themselves from the state. While there is little compunction about breaking into the private homes of migrants and requesting their papers, middle class citizens are unlikely to face this intrusion. The private household then was not just a space of abuse and arbitrary power where the state offered no protection, but also a space of refuge from the state itself. By speaking out workers literally 'made visible what has no business being seen', the work they performed, the abuse they endured, and the inhumanity permitted by a liberal democratic state.The beginning of Waling Waling lay in individual acts of resistance, in individual's refusal to endure any more and in them taking the huge step of escape(Papadopoulos et al. 2008).These were brave moves, and it was in the sharing of this and subsequent experiences that domestic workers turned them into political acts. The first action of citizenship is

  Waling Waling members claimed legitimacy as political actors then on the basis of their legitimacy as economic actors. This claim was directed at the state, but Waling Waling also turned to other groups, religious, human rights and labour organizations for recognition both for its own sake and as a means of pressurizing the state. The trade union the Transport and General Workers Union (TGWU) played an important symbolic and material role through its recognition of migrant domestic workers as workers. The fact that they welcomed their membership, despite the sector they worked in and their immigration status gave a real boost to the organization and to individuals. Of enormous importance to the migrants, many of whom were without their passports, was the possession of a union membership card. This was viewed, partly as a document confirming their identity, and partly as a way of demonstrating that they belonged to an officially recognized organization. This made members feel less vulnerable and with some protection from the police and immigration. There were additional benefits: workers were given advice and support at special meetings to advise them on what little employment rights they had. Organisationally the TGWU supported domestic workers' participation in Labour Party conferences (and politicians' commitments at those conferences were later to prove critical). Crucially membership of the TGWU meant that Waling Waling could bring the issue of migrant domestic workers before grassroots TGWU membership, and learn about the experiences of other low waged workers, particularly women, in the UK.

  practice. It was particularly difficult for those with family member visas to be regularized, as there was reluctance on the part of the Home Office to 'open the floodgates' by offering regularization to overstayers of visitors' visas, as they feared abuse of the regularization process. So the decision of the immigration officer, the individual official who admitted them, continued to shape workers' chances. This mapped on to other racialized and nationalized constraints and facilities (including the relative supportiveness of different embassies). For example, many of the Filipinos had entered the UK via the Middle East, and had gone to the Middle East through an agency. While they did not particularly intend to come to the UK, they had a specific migratory project. They were often well educated with a high degree of English fluency. In contrast, many of the Indians had come to the UK with wealthy Indian employers. They themselves were rural to urban migrants, often with little English or

  workers and helped develop a clear strategy and demands, was also at this stage something of its weakness. Where to go from here was not immediately clear. Being parted from loved ones and from time consuming responsibilities that caring brings, meant that migrants had devoted time to political struggles, time which they often now wanted to spend rebuilding family relationships that had suffered severely as a result of immigration status. The organizations had not developed a means of opening political possibilities from this reprioritization, but rather were struggling with individual case work. The case by case nature of the regularistion thus posed problems both at an individual and an organizational level.One step forward, two steps back?Fast forward to March 2006 when the Home Office came forward with new proposals, Waling Waling (renamed the United Workers Association) was largely inactive. Kalayaan had become a professionalized registered charity offering 'advice, advocacy and support' and widely recognized both inside and outside of government as able to provide expert advice on issues around the migrant domestic worker visa. At this time the UK government announced it was to introduce a 'points-based system' as part of 'Making Migration Work for Britain' agenda. This aimed to limit economic migration to the UK principally to those with 'skills' that are in demand(Home Office 2006). As part of these changes the government determined to change its policy in respect of migrant domestic workers UK accompanying their employer. It was proposed that they would have the name of their employer written on their passport, enter as a 'business visitor' (i.e. not a worker and with no employment protection) and have a maximum stay of six months. This would give the employer time to train up an EU migrant to take this work (note that it was still not proposed that they train up a UK national).Kalayaan challenged the Home Office proposals on the grounds that they constituted 'trafficking' by turning domestic workers into trafficking victims[START_REF] Kalayaan | Migration Must Work for Workers Too: A Campaign Statement[END_REF]. Trafficking was not a term in common usage in the 1990s but it had since risen on the political and popular agenda. Governments, particularly in Europe, blame traffickers for the proliferation of irregular migration and the abuse of migrant workers. The government has as a stated aim to 'make the UK a hostile environment for trafficking' (Home Office 2007b) and a whole raft of policies and initiatives have been developed in order to counter this problem.'Trafficking' has replaced asylum as a means of resolving tensions between immigration controls and human rights[START_REF] Davidson | Children in the global sex trade[END_REF]. Stricter immigration controls help prevent trafficking and exploitation and therefore are to the benefit of migrant workers who would otherwise be abused. This is a relatively new discursive development. In 2002 numbers of victims of trafficking (VoT) were 'small' and the majority of illegal migrants were held to be in the UK 'by their consent' (Home Office 2002). But five years later, organised crime seems to have taken by the scruff of the neck and by 2007 then Home Secretary John Reid was warning that Failure to take on the people traffickers, who are behind threequarters of illegal immigration to this country, leaves vulnerable and often desperate people at the mercy of organised criminals.

  only. In practice only the most victimized who are unable to act for themselves can qualify as Victims of Trafficking and become entitled to the state's assistance and protection. The figure of the evil employer and trafficker throws a shadow over the role of the state in constructing vulnerability. For the individual victim it is the employer, pimp etc who denies access to basic social rights such as medical treatment. But if these individuals were not denying access, for those who are illegalized, the state would. Indeed state legitimated restriction of access to social rights is a key source of vulnerability. The state that 'rescues' victims of trafficking in response to a claim to human rights, is the same state that denies access to rights on the basis of non-citizenship (Sharma 2003).

  In its critique of the government proposalsKalayaan underscored the relation between employers' coercion and abuse of their workers with the British state's proposed immigration legislation. It foregrounded physical coercion but went further to argue that this would be reinforced by a state-enforced inability to leave an employer.Thirty two per cent of migrant domestic workers who registered atKalayaan during 2005Kalayaan during -2006 had their passports withheld by their employer, and 23% had been physically abused. The removal of any option to challenge or leave an abusive or exploitative employer is in direct contravention to the Home Office stated policy to protect victims of trafficking and to stop trafficking 'at source'.[START_REF] Kalayaan | Migration Must Work for Workers Too: A Campaign Statement[END_REF] Thus immigration controls were presented as potentially part of the problem.The UK Home Office in contrast emphasized that immigration controls can be used to refuse entry to abusive individual employers. This is in line with the UK Trafficking Action Plan which recognises borders as points of intervention:As part of our continued work to combat trafficking, our emphasis will be upon developing robust pre-entry procedures, including appropriate safeguards, such as the identification of cases of possible abuse at the pre-entry stage to minimise the risk of subsequent exploitation.

  . Because they can only be helped and rescued they are not political subjects, rather the objects of negotiation. Since they cannot actualise their rights, they must be given to others to act on their behalf (Zizek 2005), and indeed there has been a veritable plethora of antitrafficking organizations and initiatives. But the organizations cannot be comprised of trafficked people -for they are the victims. So the language of trafficking means that one cannot engage with the notion of citizenship as process, but only with citizenship as formal legal status administered by the state -and citizenship as formal legal status is a long way off being granted victims of trafficking.

  a significant difference to the lives of thousands of workers and their family members and developed a lasting sense of political agency. When the Home Office announced its 2006 proposals a meeting was organised at the Transport and General Workers Union. More than three hundred migrant domestic workers, some from the 'old' Waling Waling, some from the new 'client base' of

  However, after only a few months non-Filipinos began to join the organization, initially as a result of contacts established in wealthy households which often employed more than one nationality of domestic worker. Thus the material reality of the arrangement of work for migrants in private households, rather than nationality, shaped the organising of migrant domestic workers. At an individual level this meant that networks and contacts established within often oppressive private homes, became an important resource that some workers managed to tap. As the

	F o r F o r
	P P
	e e
	e r e r
	R R
	e e
	v i e v i e
	w w
	O n l O n l
	y y
	Legal and substantive citizenship: the case of migrant domestic
	workers

this was highly unusual in the mid 1980. It is important to note too that this multinational organizing was also a new development in the European and international organization of Filipinos.

The CFMW had offices in several European states and had originally been established by activists and refugees many of whom had been organizers in the anti-Marcos groups in the Philippines. It therefore had a strong orientation towards the nationalist struggle in the Philippines. organization grew, approximately half were Filipinos, with considerable numbers of Indians and Sri Lankans, and smaller numbers from Anglophone and Francophone African states. In all more than 30 nationalities were members, but notably none from Eastern Europe, and very few from Latin America.

In 1987 the organization Kalayaan was founded. Waling Waling became a self-organised group with a membership of domestic workers, while Kalayaan comprised their supporters. The two worked closely together, but while Waling Waling members were on the management committee of Kalayaan (but not vice versa) in order to facilitate accountability to migrant domestic workers.

  . Indeed, while able bodied citizens have a duty to work non-citizens' access to the labour market is generally highly regulated low waged sectors, this work is both 'priceless' and yet not one that is unfairly being snatched from British nationals, for, while valued in rhetoric it is not valued economically. It is one thing to acknowledge the value and dignity of the work in theory, and another to pay for it.

	There were also ways in which the intrusion of domestic workers F was used to reinforce ideas about 'foreigners'. Honig has elucidated how o r political communities, often with a myth of the 'foreign founder', re-found
	P
	e
	e r
	R
	e
	v i e
	w
	O n l
	y

and indeed for some, working may result in deportation. It is rarely questioned in public discourse that British people have prior claim to work, and it is not assumed that migrants generate a right to citizenship through work, particularly when they are working 'illegally'. However, when migrant domestic workers 'intruded' into the public space there were important ways in which the very mechanisms that work to exclude migrants and to exclude domestic workers facilitated the recognition of migrant domestic workers. Importantly, domestic work in private households (like sex work) is not constructed as a sector where jobs are 'taken' from British workers. Rather, when it is acknowledged that paid domestic work takes place, the home is imagined as a space where jobs are made, with British women having their entry to the labour market facilitated through domestic employees. Moreover (and in this instance, unlike sex work), domestic work, though low status, is often rhetorically valued, especially when it involves care of the elderly or children

[START_REF] Cox | The Servant Problem: Domestic Employment in a Global Economy[END_REF][START_REF] Hondagneu-Sotelo | Domestica: Immigrant Workers Cleaning and Caring in the Shadows of Affluence[END_REF]

. Thus, unlike many other themselves with reference to foreigners

[START_REF] Honig | Democracy and the Foreigner[END_REF]

. She examines the perpetual revisiting and reinterpreting of the migrant as founder and as threat and asks 'what problems does foreignness solve for us?' in order to unpack how the symbolic politics of foreignness reinstills ideas of 'heartfelt community…. And a consent producing liberal individualism'

  emphasised the role of the state in forging the conditions within which abusive employment practises -and hence 'trafficking' can occur, the UK government presented itself as a combater of trafficking from the outside.

	The question becomes to do with the broader issue of the role of
	immigration controls in constructing categories of people who are
	vulnerable to abuse. If certain immigration statuses create marginalized F groups without access to the formal labour market, or any of the o r protections usually offered by states to citizens and workers, then how
	P can the state prevent itself equipping employers with labour control and
	e retention mechanisms that would not otherwise be available to them?
	e r
	R
	e
	v i e	Immigration
	control per se cannot be considered as a coercive tool that is used by w
	employers. This is a fundamental difference between the approaches of states and many of those who would argue for migrants' rights that goes O n l to the heart of the relation between the state and employers. It could be argued that immigration control limits the rights of migrants as workers by y
	giving employers additional mechanisms of control over labour and
	indeed some might argue by limiting freedom of labour (Steinfeld 2008).
	However in this case immigration controls are presented as part of a
	toolkit to detect and refuse entry to abusers. So while Kalayaan

  Kalayaan, attended to voice their protest. In late 2008 building on this work a core group began to organise, offering mutual support, solidarity with trades union struggles and protesting against the new Immigration and Citizenship Bill…..watch this space….. BRIDGET ANDERSON is a senior researcher at the Centre on Migration, Policy and Society (COMPAS), University of Oxford. Papadopoulos, Dimitris, Niamh Stephenson and Vassilis Tsianos. 2008. Escape Routes: Control and Subversion in the 21st century. London: Pluto Press. Pateman, Caroline. 1988. The Sexual Contract. Cambridge: Polity Press. Rancière, Jacques. 2004. 'Who Is the Subject of the Rights of Man?' South Atlantic Quarterly 103(2/3):297-310. Sharma, Nandita. 2003. 'Travel Agency: a critique of anti-trafficking campaigns.' Refuge 21(3). Steinfeld, Robert J. 2008. 'Coercion/consent in labour.' In COMPAS Annual Conference: Theorizing Key Migration Debates St Anne's College, University of Oxford. Zizek, Slavoj. 2005. 'Against Human Rights.' New Left Review 34(2):115-131.

	Page 28 of 28
	F o r F o r F o r
	P P P
	e e e
	e r e r e r
	R R R
	e e e
	ADDRESS: COMPAS, 58 Banbury Road, Oxford, OX2 6QS, UK. Email: v i e v i e v i e bridget.anderson@compas.ox.ac.uk w w w
	O n l O n l O n l
	y y y

URL: http://mc.manuscriptcentral.com/rers ethnic@surrey.ac.uk

Ethnic and Racial Studies


I Abuzayan

U Paraskavi

S W Turner

Changes to exhaled nitric oxide in asthmatic children after drinking a caffeine-containing cola drink

Keywords: asthma, caffeine, nitric oxide asthma, caffeine, nitric oxide asthma, caffeine, nitric oxide

word count 236)

Introduction. Exhaled nitric oxide (FE NO ) may be a biomarker for airway eosinophilia and of use in the management of childhood asthma. Caffeine ingestion has been associated with changes in FE NO concentration in adults. The present study tested the hypothesis that ingestion of a caffeine-containing cola drink will increase FE NO in asthmatic children.

Methods. Exhaled NO was measured in children with asthma before, 30 and 60 minutes after taking a cola drink containing 2.5mg/kg caffeine. Intrasubject changes in FE NO and flow independent NO parameters were determined including bronchial wall NO flux (J'awNO).

Results.

Eleven children with asthma were recruited, 10 were prescribed inhaled corticosteroids and 9 were skin prick positive. The median [interquartile range, IQR] FE NO at baseline was 47 parts per billion [9, 64] and this rose to 56ppb [11, 66] after 30 minutes and returned to 46ppb [9, 62] after 60 minutes, Friedman's test p=0.003. J'awNO rose from a median [IQR] 2843nl/s [356, 4247] at baseline to 3304nl/s [479, 4387] after 30 minutes and returned to 2937nl/s [356, 4153] after 60 minutes, Freidman's test p=0.003. There was no significant change in other flow independent NO parameters. Conclusions. Ingestion of a caffeine-containing cola drink was associated with a modest and transient rise in FE NO which is mostly explained by increased NO production in the proximal airways. Ingestion of a caffeine-containing cola drink may result in clinically relevant acute changes in FE NO for children with asthma.

INTRODUCTION

Exhaled nitric oxide (FE NO ) is a non-invasive biomarker for airway eosinophilia 1 and may be useful to monitor asthma control [2][3][4] . Measurements of FE NO can be variable within an asthmatic independent of symptoms 5 and this suggests that factors other than asthma might influence FE NO with implications for clinical application.

Factors other than asthma which are associated with altered FE NO in children include atopy 6 , hayfever 7 , age 8 , height 6 , ingestion of L-arginine 9 and possibly exposure to tobacco smoke 10 . There is at least one potential mechanism whereby caffeine might also acutely influence FE NO values in children. Caffeine ingestion has been associated with altered FE NO values in adults although the results are inconsistent; the three published studies have respectively found exposure resulting in increased FE NO 11 , reduced FE NO 12 or no change in FE NO 13 . In an observational study, our group has observed an association between intake of carbonated drinks (the predominant source of caffeine in children) and increased FE NO in atopic five year olds 14 .

Given that many children are regularly exposed to caffeine-containing carbonated drinks 15 there is the potential for such exposure to confound FE NO measurements in children with asthma. We therefore designed an intervention study to test the hypothesis that exposure to a caffeine-containing carbonated drink increases FE NO values in atopic asthmatic children. Our second hypothesis was that exposure to caffeine increases proximal and not distal airway nitric oxide production.

METHODS

Study design. At a single assessment, FE NO , skin prick reactivity and spirometry were measured in children with asthma. A dose of 2.5mg/kg caffeine in a carbonated cola drink was ingested (5.5ml/kg of Diet Coke 45.6mg caffeine/100mls); for a 40kg child this was equivalent to 220mls or two thirds of a standard 330ml can. Exhaled NO was measured 30 and 60 minutes after ingestions. Proximal and distal airway contributions to exhaled NO were derived from a non-linear method 16 . The study was approved by the local research ethics committee; written parental consent and verbal assent from the child were obtained.

Enrolment. Children attending a hospital asthma clinic with a prior physician diagnosis of asthma were eligible. Children aged under 6 years were not eligible since FE NO measurements are not obtained in a large proportion of such young children 17 . Children were free of respiratory symptoms on the day of testing.

Exhaled NO measurements. A chemiluminescence analyser (NIOX, Aerocrine, Sweden) was used to measure FE NO in real time in accordance with international recommendations 18 . Baseline FE NO was measured before spirometry. Exhaled NO was measured at 10, 30, 50, 100 and 200 ml/s. The nonlinear method of Silkoff 16 was used to derive alveolar NO (CANO, units ppb), airway wall NO flux (J'awNO, units pl/s), the mean airway wall concentration of NO (CawNO, units ppb) and total airway compartment diffusing capacity for transfer of NO from the airway wall to the gas phase (DawNO, units pl/ppb/s) using a previously validated software programme 19 .

Skin prick reactivity. were used and international recommendations for quality control were applied.

Power calculation. Based on our previous report 17 where the mean difference in repeated FE NO measurements over 24 hours was 0.2ppb with a standard deviation of 2.2, a study of 10 individuals would have power at >90% to detect an intrasubject difference in FE NO of 4 ppb at the 5% level of significance.

Statistics. Within subject differences were studied using Wilcoxon's test for two variables and Friedman's test for three variables taken from the same individual.

Significance was assumed at the 5% level. A standard statistical package was used (SPSS version 17.0.0).

F

RESULTS

Changes in FE NO

Eleven children were recruited and their details at baseline are presented in table one. The present study findings are consistent with a previous report linking elevated FE NO and ingestion of carbonated drinks among atopic children 14 . The previous observational study was not able to determine causation and was limited by only being able to consider all carbonated drinks rather than only caffeine-containing drinks 14 . The present intervention study is also consistent with a study where FE NO was measured in adults before and after a cup of coffee 11 . In their study of non-asthmatic adults, Warke et al 11 reported FE NO rising after ingestion of caffeine from 5.4ppb to 8.3ppb after 30 minutes and returned to baseline after one hour. Our results are not consistent with two studies in adults which found no effect 13 or a negative 12 effect of caffeine exposure on FE NO . The reason for the different outcomes between studies is not clear but some included asthmatic 13 and others non-asthmatic 11 12 individuals and the dose of caffeine varied from 11 , to 200mls coffee 12 13 (equivalent to 100mg caffeine) or 200mg caffeine 12 .

Chronic caffeine intake may possibly have confounded the acute FE NO response to ingestion and atopy may be a further confounder 14 . Children are not small adults and it may not be appropriate to compare the present study with adult studies but the consensus of all intervention studies is that any acute change in FE NO after ingestion of a caffeinecontaining drink is transient and relatively minor.

This is the first study to separately consider changes in proximal and distal airway NO production after exposure to caffeine-containing drinks. Our observation that proximal airway NO turnover (J'awNO), and not delivery of NO to the distal airway (CANO), increased after exposure is consistent with the paradigm that the excess NO in asthma arises from the proximal airways due to upregulated activity of nitric oxide synthase (NOS) in the airway epithelial cells 20 . All but one of the study participants were treated with inhaled steroids and in adults this treatment is thought to preferentially suppress proximal airway NO production 21 and it is possible that the effect of cola drink on FE NO and J'awNO in steroid naïve children with asthma may be more marked.

We have previously reported that ingestion of L-arginine leads to an increase in FE NO which was maximal after 60 minutes and which was associated with increased NO in the distal airways 9 . Here we demonstrate that a second dietary exposure also appears to influence NO metabolism in the child's airway but in a separate compartment of the airway and with different time to peak effect. Assuming that caffeine was modifying NO production in our study participants, the mechanism where exposure might influence Alternatively, caffeine has a weak bronchodilator action in children 23 at larger doses than used in the present study (i.e. 10mg/kg) and may elevate FE NO by increasing the surface area of lung from which NO can diffuse; the peak effect of caffeine on lung function is seen after two hours 23 which contrasts with the peak rise in FE NO after 30 minutes reported here. This study was not designed to describe a mechanism whereby cola drink ingestion increases FE NO and since we did not measure plasma or salivary caffeine and did not use a caffeine-free cola arm to the study we cannot be certain that the changes in FE NO were due to caffeine exposure.

There are a number of factors which should be considered when interpreting these results.

First, we have previously demonstrated that FE NO measurements are reproducible over a period of hours and thus the study was powered to determine intrasubject differences in FE NO of as little as 4ppb. One limitation is that the study was not adequately powered to study changes in flow independent parameters and it is possible that with a larger number of participants we may have been able to detect changes in parameters in addition to J'awNO; the limits of agreement are known to be wider for CANO compared to J'awNO 24 . A second limitation is that we did not measure caffeine and therefore it is possible that another constituent in the cola drink may have influenced the result and we acknowledge this limitation. Third, although values of flow independent parameters are mostly consistent with published values for asthmatic children 25 , the median value of CANO was relatively low and this index could not be determined in several individuals; it is known that flow independent parameters cannot be determined in approximately one quarter of individuals 24 . Finally, it is possible that NO may have been released into the mouth ("oral contamination") after the cola drink and therefore falsely elevated FE NO values. However, in adults FE NO values are not changed after a drink of distilled water 26 and are reduced after an antibacterial mouth wash 26 Changes to exhaled nitric oxide in asthmatic children after drinking a caffeine-containing cola drink

INTRODUCTION

Exhaled nitric oxide (FE NO ) is a non-invasive biomarker for airway eosinophilia 1 and may be useful to monitor asthma control [2][3][4] . Measurements of FE NO can be variable within an asthmatic independent of symptoms 5 and this suggests that factors other than asthma might influence FE NO with implications for clinical application.

Factors other than asthma which are associated with altered FE NO in children include atopy 6 , hayfever 7 , age 8 , height 6 , ingestion of L-arginine 9 and possibly exposure to tobacco smoke 10 . There is at least one potential mechanism whereby caffeine might also . In an observational study, our group has observed an association between intake of carbonated drinks (the predominant source of caffeine in children) and increased FE NO in atopic five year olds 14 .

acutely
Given that many children are regularly exposed to caffeine-containing carbonated drinks 15 there is the potential for such exposure to confound FE NO measurements in children with asthma. We therefore designed an intervention study to test the hypothesis that exposure to a caffeine-containing carbonated drink increases FE NO values in atopic asthmatic children. Our second hypothesis was that exposure to caffeine increases proximal and not distal airway nitric oxide production. . Baseline FE NO was measured before spirometry. Exhaled NO was measured at 10, 30, 50, 100 and 200 ml/s. The nonlinear method of Silkoff 16 was used to derive alveolar NO (CANO, units ppb), airway wall NO flux (J'awNO, units pl/s), the mean airway wall concentration of NO (CawNO, units ppb) and total airway compartment diffusing capacity for transfer of NO from the airway wall to the gas phase (DawNO, units pl/ppb/s) using a previously validated software programme 19 .

F

Skin prick reactivity.

Changes in NO flow independent parameters

These data are presented in table 2. There was a significant rise in J'awNO 30 minutes after drinking the cola drink, but no other parameters were different from baseline after ingestion of cola drink. The present study findings are consistent with a previous report linking elevated FE NO and ingestion of carbonated drinks among atopic children 14 . The previous observational study was not able to determine causation and was limited by only being able to consider all carbonated drinks rather than only caffeine-containing drinks 14 . The present intervention study is also consistent with a study where FE NO was measured in adults before and after a cup of coffee 11 . In their study of non-asthmatic adults, Warke et al 11 reported FE NO rising after ingestion of caffeine from 5.4ppb to 8.3ppb after 30 minutes and returned to baseline after one hour. Our results are not consistent with two studies in adults which found no effect 13 or a negative 12 effect of caffeine exposure on FE NO . The reason for the different outcomes between studies is not clear but some included asthmatic 13 and others non-asthmatic 11 12 individuals and the dose of caffeine varied from 11 , to 200mls coffee 12 13 (equivalent to 100mg caffeine) or 200mg caffeine 12 .

Chronic caffeine intake may possibly have confounded the acute FE NO response to ingestion and atopy may be a further confounder 14 . Children are not small adults and it may not be appropriate to compare the present study with adult studies but the consensus of all intervention studies is that any acute change in FE NO after ingestion of a caffeinecontaining drink is transient and relatively minor.

This is the first study to separately consider changes in proximal and distal airway NO production after exposure to caffeine-containing drinks. Our observation that proximal airway NO turnover (J'awNO), and not delivery of NO to the distal airway (CANO), increased after exposure is consistent with the paradigm that the excess NO in asthma arises from the proximal airways due to upregulated activity of nitric oxide synthase (NOS) in the airway epithelial cells 20 . All but one of the study participants were treated with inhaled steroids and in adults this treatment is thought to preferentially suppress proximal airway NO production 21 and it is possible that the effect of cola drink on FE NO and J'awNO in steroid naïve children with asthma may be more marked.

We have previously reported that ingestion of L-arginine leads to an increase in FE NO which was maximal after 60 minutes and which was associated with increased NO in the distal airways 9 . Here we demonstrate that a second dietary exposure also appears to influence NO metabolism in the child's airway but in a separate compartment of the airway and with different time to peak effect. Assuming that caffeine was modifying NO production in our study participants, the mechanism where exposure might influence Alternatively, caffeine has a weak bronchodilator action in children 23 at larger doses than used in the present study (i.e. 10mg/kg) and may elevate FE NO by increasing the surface area of lung from which NO can diffuse; the peak effect of caffeine on lung function is seen after two hours 23 which contrasts with the peak rise in FE NO after 30 minutes reported here. This study was not designed to describe a mechanism whereby cola drink ingestion increases FE NO and since we did not measure plasma or salivary caffeine and did not use a caffeine-free cola arm to the study we cannot be certain that the changes in FE NO were due to caffeine exposure.

There are a number of factors which should be considered when interpreting these results.

First, we have previously demonstrated that FE NO measurements are reproducible over a period of hours and thus the study was powered to determine intrasubject differences in FE NO of as little as 4ppb. One limitation is that the study was not adequately powered to study changes in flow independent parameters and it is possible that with a larger number of participants we may have been able to detect changes in parameters in addition to J'awNO; the limits of agreement are known to be wider for CANO compared to J'awNO 24 . A second limitation is that we did not measure caffeine and therefore it is possible that another constituent in the cola drink may have influenced the result and we acknowledge this limitation. Third, although values of flow independent parameters are mostly consistent with published values for asthmatic children 25 Our research question was Does exposure to caffeine-containing carbonated drink increase FE NO values? We believe our study was designed appropriately and addressed this question. The reviewer raises a second question of "Does exposure to caffeine increase FE NO values" and we agree this is an interesting question but as the reviewer notes, our study was not designed to address this question. In our original manuscript we addressed this potential limitation and stated that "This study was not designed to describe a mechanism whereby cola drink ingestion increases FE NO and since we did not measure plasma or salivary caffeine and did not use a caffeine-free cola arm to the study we cannot be certain that the changes in FE NO were due to caffeine exposure." We believe our pragmatic study has addressed a clinically relevant issue but we acknowledge that the underlying mechanism is still unexplained. It is furthermore not clear, if oral contamination can explain at least a part of the FeNO changes, although this is unlikely as standardized procedures for FeNO-testing were used.

We agree with the reviewer that oral contamination of FENO is unlikely to have explained part of the FENO change since we did use the standard methodology. Mouth wash has been with a reduction in FENO rather than an elevation such as we observed.

We have amended the text to address this issue (last sentence of discussion)

A further suggestion would be to enroll steroid naive asthmatics, as the influence of ICS on FeNO is likely much bigger than that of caffeine.

We agree that a study of the role of caffeine exposure on FENO in steroid naive asthmatic children is of interest. However the majority of children with asthma are treated with inhaled steroids and the present results are therefore relevant to many children

The authors state that the changes observed were not clinically meaningful, although they showed changes of as much as 35% (Figure 1) and therefore they can be meaningful as a confounder for testing.

We have amended the conclusions in the abstract and discussion in light of the conclusions made by both reviewers

In summary, although the study raises an interesting question (influence of caffeine on FeNO measures), it does not use the proper methodology to answer it.

As previously discussed, the present study was not designed to relate caffeine exposure to FENO per se, rather exposure to cola drink to FENO

8 FE

 8 NO is likely to involve adenyl cyclases. Caffeine is a phosphodiesterase inhibitor and thus may increase cAMP which in turn induces nitric oxide synthase activity22 .

6 DISCUSSION

 6 This intervention study was designed to address the findings of an observational study which suggested that ingestion of carbonated drinks might substantially influence FE NO measurements in children14 . There were two findings which arose from the present study. First, drinking a caffeine-containing cola drink was associated with a short-lived and possibly clinically-relevant increase in FE NO values in children with asthma. Second, a change was apparent in the proximal, but not distal, delivery of NO to the airways after ingestion of the cola drink. These findings add to what is understood about NO production in the airways and how this may be affected by constituents of cola drink.Clinicians might advise that cola drinks should not be drunk within an hour of FE NO values in asthmatic children treated with inhaled steroids.

  The results should assure Deleted: c Deleted: that acute ingestion of Deleted: will have no clinically meaningful influence on

8 FE

 8 NO is likely to involve adenyl cyclases. Caffeine is a phosphodiesterase inhibitor and thus may increase cAMP which in turn induces nitric oxide synthase activity22 .

  , possibly due to a reduction in oral NO-producing bacteria. Acidity might confer antibacterial properties on a cola drink and this would reduce FE NO values and thus we do not believe that oral contamination could explain the elevated FE NO values seen after ingestion of the cola drink.

	FIGURE LEGEND
	Figure 1. Exhaled nitric oxide (FE NO ) values before (T0) and thirty (T+30) and sixty
	(T+60) minutes after ingestion of cola drink in eleven children with asthma. Circles
	correspond to skin prick positive children and triangles skin prick negative children.
	Wilcoxon's test p=0.003 for differences between FE NO values at the three time points for
	a given individual.
	F o F o F o F o
	r r r r
	P P P P
	e e r e e r e e r e e r
	R e v i e w R e v i e w R e v i e w R e v i e w

  influence FE NO values in children. Caffeine ingestion has been associated with altered FE NO values in adults although the results are inconsistent; the three published studies have respectively found exposure resulting in increased FENO 11 , reduced FE NO

12

or no change in FE

NO 13

  Study design. At a single assessment, FE NO , skin prick reactivity and spirometry were measured in children with asthma. A dose of 2.5mg/kg caffeine in a carbonated cola drink was ingested (5.5ml/kg of Diet Coke 45.6mg caffeine/100mls); for a 40kg child this was equivalent to 220mls or two thirds of a standard 330ml can. Exhaled NO was measured 30 and 60 minutes after ingestions. Proximal and distal airway contributions to exhaled NO were derived from a non-linear method16 . The study was approved by the local research ethics committee; written parental consent and verbal assent from the child were obtained.Enrolment. Children attending a hospital asthma clinic with a prior physician diagnosis of asthma were eligible. Children aged under 6 years were not eligible since FE NO measurements are not obtained in a large proportion of such young children17 . Children were free of respiratory symptoms on the day of testing.

	METHODS
	o
	r
	P
	e e r
	R e v i e w
	3

Exhaled NO measurements. A chemiluminescence analyser (NIOX, Aerocrine, Sweden) was used to measure FE NO in real time in accordance with international recommendations

18

  The skin prick test was used to ascertain sensitisation to egg, house dust mite, grass and cat dander. Positive and negative controls were used and a positive Eleven children were recruited and their details at baseline are presented in table one.

	reaction was defined as a weal at least 3mm in longest diameter or, in cases of RESULTS
	dermatographism, a weal greater than the negative control. All reagents were supplied by Changes in FE NO
		Deleted: k
	Alk-Abello (Northampton, UK).
	Spirometry. Figure one shows FE NO values at baseline and 30 and 60 minutes after ingestion of the A pneumotachygraph (Vitalograph 20/20, Vitalograph, UK) and
	commercially available software (Spirotrac IV version 4.22, Vitalograph, Bucks, UK) cola drink. Thirty minutes after ingestion of caffeine, FE NO had risen from a median of
	were used and international recommendations for quality control were applied. 47ppb [inter quartile range, IQR 9, 64] to 56 ppb [11, 66] Wilcoxon's test p=0.003
	Power calculation. Based on our previous report 17 where the mean difference in repeated equivalent to a median [IQR] % change of +15% (4, 28), table two. Sixty minutes after
	FE NO measurements over 24 hours was 0.2ppb with a standard deviation of 2.2, a study ingestion, the median [IQR] FE NO was 46ppb [95% CI 9, 62] Wilcoxon's test p=0.203
	F o of 10 individuals would have power at >90% to detect an intrasubject difference in FE NO of 4 ppb at the 5% level of significance. compared to baseline and equivalent to a median (IQR) % change of -1% (-5, 0), table F o two. The overall change in absolute FE NO values was significant, Freidman's test
	p=0.003.	r r
		P P
		e e r e e r
		R e v i e w R e v i e w
		4 5

Statistics. Within subject differences were studied using Wilcoxon's test for two variables and Friedman's test for three variables taken from the same individual.

Significance was assumed at the 5% level. A standard statistical package was used (SPSS version 17.0.0).

Table 1 .

 1 , the median value of CANO was relatively low and this index could not be determined in several individuals; that flow independent parameters cannot be determined in approximately one quarter of individuals24 . Finally, it is possible that NO may have been released into the mouth ("oral contamination") after the cola drink and therefore falsely elevated FE NO values. However, in adults FE NO values are not changed after a drink of distilled water26 and are reduced after an antibacterial mouth wash26 , possibly due to a reduction in oral NO-producing bacteria. Acidity might confer antibacterial properties on a cola drink and this would reduce FE NO values and thus we do not believe that oral contamination could explain the elevated FE NO values seen after ingestion of the cola drink. Details of study participants.

	it is known Formatted: Subscript
	Deleted: 26
	Formatted: Subscript
	Formatted: Subscript
	Formatted: Subscript
	F o
	r
	P
	e e r
	R e v i e w
	9

Table 2 .

 2 Median percentage changes and absolute values of FE NO , proximal airway NO flux (J'awNO), alveolar NO (CANO), diffusion capacity for transfer of NO from airway wall to lumen (DawNO) and concentration of NO in the airway wall (CawNO) before and 30 and 60 minutes after ingestion of caffeine-containing carbonated drink. IQR= interquartile range. *Freidman's test for comparison of absolute values (e.g. FE NO at baseline and after 30 and 60 minutes) and Wilcoxon signed ranks test for comparison of percentage changes (e.g. % change in FE NO 30 and 60 minutes after ingestion). Fig1would be better with the actual value of FENO on the 'y'-axis with a connector line linking individual patients values at baseline, 30 and 60 mins. This is important so that the change from initial baseline value can be seen ie are the bigger rises at 30mins mainly in those with high initial values. This also allows the reader to see the changes that have occured in children whose baseline value is at or near the cutoffs for high/low eg between 20-30ppb.The figure and accompanying legend has been amended as suggested by the reviewer 3] I think the authors may be understating or even dismissing the magnitude of the rise in FENO observed at 30 mins -this finding would make me want to recommend that FENO is measured at least 60 mins after a drink of Diet Coke ! We have amended the conclusions in the abstract and discussion in light of the conclusions made by both reviewers Using this approach, it would be easier to tell, if caffeine really changes FeNO also in children. Thus, we cannot be sure, what constituent in the cola really led to changes in FeNO. And this is, in my opinion, the more interesting question.

	F o
	r
	P
	e e r
	w e i v e R 254x190mm (72 x 72 DPI)

John Wiley & Sons, Inc.Pediatric Pulmonology