title: [Epidemiological study of selective IgA deficiency among 6 nationalities in China].
abstract: The frequency of selective IgA deficiency (SIgAD) was determined in 33,171 Chinese distributed in six nationalities by Ouchterlony's double diffusion with 5 mg/dl as the limit of detection. Those who were found IgA-deficient were retested by single radial diffusion technique. Gel diffusion analysis of sera revealed apparent lack of IgA in 8 samples, all with normal levels of IgG and IgM (age-matched). The incidence was 0.024% (1:4,100). The incidences among the six nationalities were Han 1:2,600, Hui 1:5,000, Mongolia 1:2,700, Tujia 1:4,300, Zhuang 0:5,300, and Bai 1:4,800. All of the individuals, who had low levels of IgA or no IgA detectable, were below 16 years of age. Of these, 2 sera were autoantibody (anti-smooth muscle antibody) positive Delayed hypersensitivity skin tests were negative in one individual. The chief clinical manifestations were those of respiratory tract infections, of which about 50% were in subclinical state.
authors.affiliation: Beijing Children's Hospital.
authors.forename: L
authors.initials: L
authors.lastname: Feng
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D002681:China / Q000453:epidemiology; D004406:Dysgammaglobulinemia / Q000453:epidemiology* / Q000208:ethnology; D005006:Ethnicity; D005260:Female; D006801:Humans; D017098:IgA Deficiency / Q000453:epidemiology* / Q000208:ethnology; D007223:Infant; D008297:Male; D008875:Middle Aged; D015995:Prevalence