Prevalence of Selective IgA Deficiency in Spain: More Than We Thought

To the Editor: Selective IgA deficiency (sIgA-ID) is the most common well-defined primary immunodeficiency disorder, with a frequency reported to range between 1:328 in American blood donors[1][1] and 1:18,500 in Japanese blood donors.[2][2] We report here an epidemiologic study with a frequency of