Prevalence of selective IgA deficiency in Spain: more than we thought.

Our results suggest that the prevalence of sIgA-ID is underestiSelective IgA deficiency (sIgA-ID) is the most common wellmated in the Caucasian population. It could be due to the bias in defined primary immunodeficiency disorder, with a frequency reprevalence studies with volunteer blood donors because of pathology ported to range between 1:328 in American blood donors and associated to sIgA-ID: infections in the respiratory and gastrointesti1:18,500 in Japanese blood donors. We report here an epidemiologic nal tracts or autoimmune and atopic diseases. On the other hand, study with a frequency of 0.61% (1:163), which is the highest prevasIgA-ID could be almost asymtomatic in a lot of cases and underdilence of selective IgA deficiency reported in a healthy population. agnosed in the general population. This study was performed using a In 1993, demographic information and serum samples were colpediatric sample and a transient sIgA-ID could be possible (although lected for an epidemiologic study of infectious diseases and cardionormally this is described in children less than 2 years of age). These vascular risk factors among scholars of Cáceres province (Western data could be of interest in the prevention of anaphylactic reactions Spain). One of the variables determined was the concentration of after intravenous administration of blood products containing IgA Igs (IgG, IgA, and IgM). Of a population of 80,745 individuals and in the avoidance of complications of this disease. Lack of awarebetween 2 and 16 years of age, 1,856 children were selected with ness of the real prevalence of patients with sIgA-ID has resulted in stratified random sampling, based on age, gender, and geographic underdiagnosis and diagnostic delay and inadequate management of location. All participants were volunteers responding to an applicatheir complications. tion in the schools and informed consent was obtained. Full class-