Background: Domestic endotoxin enhances airway inflammation and increases asthma severity in Caucasian children, but little data are published on indoor endotoxin exposure in Asian countries. This study investigated house dust endotoxin and Der p 1 levels in Hong Kong families with asthmatic children, and their effects on asthma severity. Methods: 115 asthmatics from a pediatric clinic underwent fractional exhaled nitric oxide (FeNO) and spirometric measurements. Home visits were then made within 2 weeks, during which parents completed the International Study of Asthma and Allergies in Childhood questionnaire. Settled dust was collected from patients’ mattresses, bedroom floors and living room floors. Endotoxin and Der p 1 were measured by limulus amebocyte lysate and immunoassay, respectively. Results: Endotoxin was detectable in all locations from all families, whereas Der p 1 was detectable in 58–70% of indoor sites. Floors of both bedroom and living rooms had higher endotoxin but lower Der p 1 levels than mattresses (p < 0.001 for both). Mattress endotoxin level correlated inversely with Der p 1 level (r = –0.308, p = 0.001). Household smoker, feather bedding and vacuum cleaning were independent determinants of indoor endotoxin. Timing of last bedding change was associated with Der p 1 levels at all sites. Mattress endotoxin level was associated with frequency of wheezing episodes (p = 0.044), but neither endotoxin nor Der p 1 was associated with FeNO and spirometric parameters. Conclusions: Domestic endotoxin levels are associated with frequency of wheezing episodes in asthmatic children but not their FeNO or spirometric measurements.

Keywords:
Chinese asthmatic children, Dermatophagoides pteronyssinus, Endotoxin
1.
Braun-Fahrlander C, Riedler J, Herz U, Eder W, Waser M, Grize L, Maisch S, Carr D, Gerlach F, Bufe A, Lauener RP, Schierl R, Renz H, Nowak D, von Mutius E, Allergy and Endotoxin Study Team: Environmental exposure to endotoxin and its relation to asthma in school-age children. N Engl J Med 2002:347:868–877.
2.
Rizzo, MC, Napitz CK, Fernández-Caldaz E, Lockey RF, Mimiça I, Solé D: Endotoxin exposure and symptoms in asthmatic children. Pediatr Allergy Immunol 1997;8:121–126.
3.
Michel O, Kips J, Duchateau J, Vertongen F, Robert L, Collet H, Pauwels R, Sergysels R: Severity of asthma is related to endotoxin in house dust. Am J Respir Crit Care Med 1996;154:1641–1646.
4.
Thorne PS, Kulhánková K, Yin M, Cohn R, Arbes SJ, Zeldin DC: Endotoxin exposure is a risk factor for asthma – The national survey of endotoxin in United States housing. Am J Respir Crit Care Med 2005;172:1371–1377.
5.
Thorne PS, Cohn RD, Mav D, Arbes SJ, Zeldin DC: Predictors of endotoxin levels in US housing. Environ Health Perspect 2009;117:763–771.
6.
Waser M, Schierl R, von Mutius E, Maisch S, Carr D, Riedler J, Eder W, Schreuer M, Nowak D, Braun-Fahrländer C, the ALEX Study Team: Determinants of endotoxin levels in living environments of farmers’ children and their peers from rural areas. Clin Exp Allergy 2004;34:389–397.
7.
Platts-Mills TAE, Rakes G, Heymann PW: The relevance of allergen exposure to the development of asthma in childhood. J Allergy Clin Immunol 2000;105:S503–S508.
8.
Lau S, Illi S, Sommerfeld C, Niggemann B, Bergmann R, von Mutius E, Wahn U: Early exposure to house-dust mite and cat allergens and development of childhood asthma: a cohort study. Multicenter Allergy Study Group. Lancet 2000;356:1392–1397.
9.
Weinmayr G, Weiland SK, Björkstén B, Brunekreef B, Büchele G, Cookson WO, Garcia-Marcos L, Gotua M, Gratziou C, van Hage M, von Mutius E, Riikjärv MA, Rzehak P, Stein RT, Strachan DP, Tsanakas J, Wickens K, Wong GW, ISAAC Phase Two Study Group: Atopic sensitization and the international variation of asthma symptom prevalence in children. Am J Respir Crit Care Med 2007;176:565–574.
10.
Eggleston PA, Rosenstreich D, Lynn H, Gergen P, Baker D, Kattan M, Mortimer KM, Mitchell H, Ownby D, Slavin R, Malveaux F: Relationship of indoor allergen exposure to skin test sensitivity in inner city children with asthma. J Allergy Clin Immunol 1998;102:563–570.
11.
Sporik R, Squillace SP, Ingram JM, Rakes G, Honsinger RW, Platts-Mills TA: Mite, cat, and cockroach exposure, allergen sensitisation, and asthma in children: a case-control study of three schools. Thorax 1999;54:675–680.
12.
Custovic A, Simpson BM, Simpson A, Hallam C, Craven M, Brutsche M, Woodcock A: Manchester Asthma and Allergy Study: low-allergen environment can be achieved and maintained during pregnancy and in early life. J Allergy Clin Immunol 2000;105:252–258.
13.
Custovic A, Simpson BM, Simpson A, Kissen P, Woodcock A: Effect of environmental manipulation in pregnancy and early life on respiratory symptoms and atopy during first year of life: a randomised trial. Lancet 2001;358:188–193.
14.
Chan-Yeung M, Ferguson A, Watson W, Dimich-Ward H, Rousseau R, Lilley M, Dybuncio A, Becker A: The Canadian Childhood Asthma Primary Prevention Study: outcomes at 7 years of age. J Allergy Clin Immunol 2005;116:49–55.
15.
Woodcock A, Lowe LA, Murray CS, Simpson BM, Pipis SD, Kissen P, Simpson A, Custovic A, NAC Manchester Asthma and Allergy Study Group: Early life environmental control – Effect on symptoms, sensitization, and lung function at age 3 years. Am J Respir Crit Care Med 2004;170:433–439.
16.
Wahn U, von Mutius E: Childhood factors for atopy and the importance of early intervention. J Allergy Clin Immunol 2001;107:567–574.
17.
Björkstén B, Sepp E, Julge K, Voor T, Milkelsaar M: Allergy development and the intestinal microflora during the first year of life. J Allergy Clin Immunol 2001;108:516–520.
18.
American Thoracic Society: Medical section of the American Lung Association: standards for the diagnosis and care of patients with chronic obstructive pulmonary disease (COPD) and asthma. Am Rev Respir Dis 1987;136:225–244.
19.
Leung TF, Tang NL, Li CY, Lam CW, Wong GW, Fok TF: Association between TARC C-431T and atopy and asthma in children. J Allergy Clin Immunol 2004;114:199–202.
20.
Leung TF, Li AM, Ha G: Allergen sensitisation in asthmatic children: consecutive case series. Hong Kong Med J 2000;6:355–360.
21.
Baraldi E, de Jongste JC, on behalf of the ERS/ATS Task Force: Measurement of exhaled nitric oxide in children. Eur Respir J 2002;20:223–237.
22.
Wong GW, Leung TF, Ko FW, Lee KK, Lam P, Hui DS, Fok TF, Lai CK: Declining asthma prevalence in Hong Kong Chinese schoolchildren. Clin Exp Allergy 2004;34:1550–1555.
23.
Weiland SK, Bjorksten B, Brunekreef B, Cookson WO, von Mutius E, Strachan DP: Phase II of the International Study of Asthma and Allergies in Childhood (ISAAC II): rationale and methods. Eur Respir J 2004;24:406–412.
24.
Sun BQ, Wu A, Chan A, Chik S, Wong D, Zhong NS: House dust mite allergen (Der p 1 and Blo t 5) levels in asthmatics’ home in Hongkong. Chin Med Sci J 2004;19:185–188.
25.
Celedón JC, Milton DK, Ramsey CD, Litonjua AA, Ryan L, Platts-Mills TA, Gold DR: Exposure to dust mite allergen and endotoxin in early life and asthma and atopy in childhood. J Allergy Clin Immunol 2007;120:144–149.
26.
Von Ehrenstein OS, Von Mutius E, Illi S, Baumann L, Bohm O, von Kries R: Reduced risk of hay fever and asthma among children of farmers. Clin Exp Allergy 2000;30:187–193.
27.
Gereda JE, Leung DYM, Thatayatikom A, Streib JE, Price MR, Klinnert MD, Liu AH: Relation between house-dust endotoxin exposure, type 1 T-cell development, and allergen sensitisation in infants at high risk of asthma. Lancet 2000;355:1680–1683.
28.
Dales R, Miller D, Ruest K, Guay M, Judek S: Airborne endotoxin is associated with respiratory illness in the first 2 years of life. Environ Health Perspect 2006;114:610–614.
29.
Leung R, Lam CW, Chan A, Lee M, Chan IH, Pang SW, Lai CK: Indoor environment of residential homes in Hong Kong – Relevance to asthma and allergic disease. Clin Exp Allergy 1998;28:585–590.
30.
Custovic A, Green R, Taggart SC, Smith A, Pickering CA, Chapman MD, Woodcock A: Domestic allergens in public places. 2. Dog (Can f 1) and cockroach (Bla g 2) allergens in dust and mite, cat, dog and cockroach allergens in the air in public buildings. Clin Exp Allergy 1996;26:1246–1252.
31.
Berge M, Munir AK, Dreborg S: Concentrations of cat (Fel d 1), dog (Can f 1) and mite (Der f 1 and Der p 1) allergens in the clothing and school environment of Swedish schoolchildren with and without pets at home. Pediatr Allergy Immunol 1998;9:25–30.
32.
Rullo VE, Rizzo C, Arruda LK, Solé D, Naspitz CK: Daycare centers and schools as sources of exposure to mites, cockroach, and endotoxin in the city of São Paulo, Brazil. J Allergy Clin Immunol 2002;110:582–588.
33.
Oldfield K, Siebers R, Crane J: Endotoxin and indoor allergen levels in kindergartens and daycare centres in Wellington, New Zealand. N Z Med J 2007;120:U2400.
34.
Zhao Z, Sebastian A, Larsson L, Wang Z, Zhang Z, Norbäck D: Asthmatic symptoms among pupils in relation to microbial dust exposure in schools in Taiyuan, China. Pediatr Allergy Immunol 2008;19:455–465.
35.
Gore R, Curbishley L, Truman N, Hadley E, Woodcock A, Langley S, Custovic A: Intranasal air sampling in homes: relationships among reservoir allergen concentrations and asthma severity. J Allergy Clin Immunol 2006;117:649–655.
36.
Hall K, Crane J, Siebers R: Endotoxin from synthetic and feather pillows. J Allergy Clin Immunol 2002;110:811.
37.
Nam H-S, Park C-S, Crane J, Siebers R: Endotoxin and house dust mite allergen levels on synthetic and buckwheat pillows. J Korean Med Sci 2004;19:505–508.
38.
Nafstad P, Nystad W, Jaakkola JJ: The use of feather quilt, childhood asthma and allergic rhinitis: a prospective cohort study. Clin Exp Allergy 2002;32:1150–1154.
39.
Arlian LG, Morgan MS: Biology, ecology, and prevalence of dust mites. Immunol Allergy Clin North Am 2003;23:443–468.
40.
Yeoh SM, Kuo IC, Wang DY, Liam CK, Sam CK, De Bruyne JA, Lee BW, Cheong N, Chua KY: Sensitization profiles of Malaysian and Singaporean subjects to allergens from Dermatophagoides pteronyssinus and Blomia tropicalis. Int Arch Allergy Immunol 2003;132:215–220.
41.
Douwes J, Zuidhof A, Doekes G, van der Zee SC, Wouters I, Boezen MH, Brunekreef B: (1→3)-Beta-D-glucan and endotoxin in house dust and peak flow variability in children. Am J Respir Crit Care Med 2000;162:1348–1354.
42.
van Strien RT, Engel R, Holst O, Bufe A, Eder W, Waser M, Braun-Fahrländer C, Riedler J, Nowak D, von Mutius E, ALEX Study Team: Microbial exposure of rural school children, as assessed by levels of N-acetyl-muramic acid in mattress dust, and its association with respiratory health. J Allergy Clin Immunol 2004;113:860–867.
43.
Nathan AT, Peterson EA, Chakir J, Wills-Karp M: Innate immune responses of airway epithelium to house dust mite are mediated through beta-glucan-dependent pathways. J Allergy Clin Immunol 2009;123:612–618.
44.
Glorieux G, Schepers E, Schindler R, Lemke HD, Verbeke F, Dhondt A, Lameire N, Vanholder R: A novel bio-assay increases the detection yield of microbiological impurity of dialysis fluid, in comparison to the LAL-test. Nephrol Dial Transplant 2009;24:548–554.
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