title: Relationship between serum IgA level and allergy/asthma.
abstract: OBJECTIVE
  Mucosal immunoglobulin A (IgA) may prevent the entrance of allergens. This study examined the relationship between serum IgA levels (within the normal range) and sensitization to house dust mites (HDM) or airway hyper-responsiveness (AHR).
  
  
  METHODS
  The clinical records of 1,136 adult patients with suspected asthma, for whom test data for serum IgA level and methacholine-AHR were available, were reviewed retrospectively. The AHR/allergy indices were compared among patient groups with low (<140 mg/dL, group I), intermediate (140 to 280 mg/dL, group II), or high (≥280 mg/dL, group III) IgA levels in serum.
  
  
  RESULTS
  The HDM skin sensitization rate progressively decreased from 30.0% in group I (n = 139) to 26.8% and 18.5% in groups II (n = 684) and III (n = 313), respectively (p= 0.003). Although both the HDM sensitization degree and the IgA level were significantly related to age, the adjusted odds ratio (OR) of association of a high IgA level (≥ 280 mg/dL) with HDM sensitization was significant (0.617; 95% confidence interval [CI], 0.415 to 0.916;p= 0.017). Among younger subjects (≤ 45 years of age) with AHR, the prevalence of moderate/severe AHR progressively decreased (70.6%, 52.3%, and 47.1% in groups I, II, and III [n = 34, 149, and 51]), respectively (p= 0.045). The IgA < 140 mg/dL was a significant risk factor for moderate/severe AHR (OR, 2.306; 95% CI, 1.049 to 5.071;p= 0.038).
  
  
  CONCLUSIONS
  Sensitization to HDM and methacholine-AHR were significantly associated with serum IgA levels in suspected asthmatics, even when those levels were normal.
authors: Department of Allergy, Chonnam National University Medical School, Graduate School and Research Institute of Medical Sciences, Gwangju, Korea.
authors: Woo-Jin
authors: WJ
authors: Kim
authors: Department of Allergy, Chonnam National University Medical School, Graduate School and Research Institute of Medical Sciences, Gwangju, Korea.
authors: Inseon S
authors: IS
authors: Choi
authors: Department of Allergy, Chonnam National University Medical School, Graduate School and Research Institute of Medical Sciences, Gwangju, Korea.
authors: Chang Seong
authors: CS
authors: Kim
authors: Department of Allergy, Chonnam National University Medical School, Graduate School and Research Institute of Medical Sciences, Gwangju, Korea.
authors: Jeong-Hyeon
authors: JH
authors: Lee
authors: Department of Allergy, Chonnam National University Medical School, Graduate School and Research Institute of Medical Sciences, Gwangju, Korea.
authors: Hyeon-Wook
authors: HW
authors: Kang
mesh_terms: D000328:Adult; D000818:Animals; D001249:Asthma / Q000097:blood* / Q000175:diagnosis / Q000276:immunology; D015415:Biomarkers / Q000097:blood; D016535:Bronchial Hyperreactivity / Q000097:blood* / Q000175:diagnosis / Q000276:immunology; D001985:Bronchial Provocation Tests; D016009:Chi-Square Distribution; D005260:Female; D006801:Humans; D006967:Hypersensitivity / Q000097:blood* / Q000175:diagnosis / Q000276:immunology; D007070:Immunoglobulin A / Q000097:blood*; D007428:Intradermal Tests; D016014:Linear Models; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D011237:Predictive Value of Tests; D039981:Pyroglyphidae / Q000276:immunology*; D012189:Retrospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index
chemical_list: D015415:Biomarkers; D007070:Immunoglobulin A
keywords: Asthma; Hyper-responsiveness; Immunoglobulin A; Sensitization