Long-term persistence of selective IgA deficiency in healthy adults

A follow-up study of 204 healthy blood donors with IgA deficiency, identified between 1971 and 1980, was carried out. Sera were initially screened by a double diffusion method and 182 were retested by a more sensitive haemagglutination inhibition method. A reexamination was performed in 1990 and, again, in 1991–1992 using an enzyme immunoassay (EIA) developed for the measurement of very low concentrations of IgA. The median follow-up period was...