Selective IgA deficiency in blood donors.
The frequency of selective deficiency of serum IgA was determined in a population of 64,588 new Finnish blood donors by Ouchterlony's double diffusion with 10 mug/ml as the limit of detection.  The incidence was 1:396.  Those found IgA-deficient were retested by hemagglutination inhibition and by radioimmunoassay.  The calculated incidences of IgA levels below 0.5 and 0.015 mug/ml were 1:500 and 1:800, respectively.  Statistically significant compensatory elevation of serum IgG was observed in the IgA-deficient donors.  The IgM levels were not changed.  Among 9,920 hospital patients, the incidence of IgA deficiency was 1:660.  The age structure of the IgA-deficient patients was similar to that of the IgA-deficient healthy blood donors but lower than that of hospital patients in general.  No difference was observed between the clinical history of IgA-deficienct blood donors and of the controls.
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000906:Antibodies; D001782:Blood Donors; D005260:Female; D005387:Finland; D006306:Health Surveys; D006385:Hemagglutination Inhibition Tests; D006801:Humans; D005779:Immunodiffusion; D007070:Immunoglobulin A / Q000032:analysis / Q000276:immunology; D007074:Immunoglobulin G / Q000032:analysis; D007075:Immunoglobulin M / Q000032:analysis; D007153:Immunologic Deficiency Syndromes / Q000175:diagnosis / Q000453:epidemiology*; D008297:Male; D008487:Medical History Taking; D008875:Middle Aged; D011863:Radioimmunoassay; D012737:Sex Factors
D000906:Antibodies; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007075:Immunoglobulin M