title: Gender, age and seasonal effects on IgA deficiency: a study of 7293 Caucasians.
abstract: BACKGROUND
  The frequency of serum IgA deficiency (SIgAD) differs between populations. We examined the prevalence of SIgAD in healthy Caucasians.
  
  
  METHODS
  Serum immunoglobulin A (SIgA) was measured in 7293 volunteers (2264 women, 5029 men) aged 30 +/- 14.2 years (mean +/- SD; range: 12-66). Serum immunoglobulin A and subnormal SIgA levels were defined by a SIgA level < 0.07 g L(-1), and between 0.07 and 0.7 g L(-1), respectively. Means were compared by analysis of variance (anova) and analysis of covariance (ancova); frequencies by the chi(2) test.
  
  
  RESULTS
  Fifteen subjects (0.21%; one woman, 14 men) had SIgAD. Subnormal SIgA levels were found in 155 persons (2.13%): 21 females (0.93% of the females) and 134 males (2.66% of the males; difference: 1.74%; 95% CI: 1.12-2.33%; P < 0.001). Males were more likely to have subnormal SIgA levels or SIgAD (odds ratio 3.09, 95% CI: 1.97-4.85). The prevalence of SIgAD and subnormal SIgA was lowest in winter (chi(2) = 14.8; P = 0.002; 3 d.f.; and chi(2) = 43.2; P < 0.001; 3 d.f., respectively). Serum immunoglobulin A concentrations were significantly higher during winter. Serum immunoglobulin A levels increased with age on average by 0.2 +/- 0.06 g L(-1) per decade of life (P < 0.001). Taking into account the influence of age, SIgA concentration was lower in females as compared with males.
  
  
  CONCLUSIONS
  The prevalence of SIgAD and subnormal SIgA levels is increased in males. There exists a significant influence of gender, age and seasons on SIgA levels.
authors.affiliation: Hospital Karl Franzens University Graz, Austria. dwebermzell@hotmail.com
authors.forename: D
authors.initials: D
authors.lastname: Weber-Mzell
authors.forename: P
authors.initials: P
authors.lastname: Kotanko
authors.forename: A C
authors.initials: AC
authors.lastname: Hauer
authors.forename: U
authors.initials: U
authors.lastname: Goriup
authors.forename: J
authors.initials: J
authors.lastname: Haas
authors.forename: N
authors.initials: N
authors.lastname: Lanner
authors.forename: W
authors.initials: W
authors.lastname: Erwa
authors.forename: I A
authors.initials: IA
authors.lastname: Ahmaida
authors.forename: S
authors.initials: S
authors.lastname: Haitchi-Petnehazy
authors.forename: M
authors.initials: M
authors.lastname: Stenzel
authors.forename: G
authors.initials: G
authors.lastname: Lanzer
authors.forename: J
authors.initials: J
authors.lastname: Deutsch
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000375:Aging / Q000276:immunology; D001317:Austria / Q000453:epidemiology; D002648:Child; D005260:Female; D006801:Humans; D017098:IgA Deficiency / Q000453:epidemiology*; D007070:Immunoglobulin A / Q000097:blood; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012016:Reference Values; D012621:Seasons; D012737:Sex Factors
chemical_list: D007070:Immunoglobulin A