RESUMEN
Selective IgA deficiency has been reported to be the most common primary immunodeficiency disease in Western countries. A markedly lower frequency of this condition has been reported in the Japanese population. While most of the IgA deficient cases are healthy, some patients develop significant recurrent sinopulmonary infections, allergic disorders and autoimmune diseases. Herein, we report three cases of IgA deficiency among Thai patients, all of whom suffered from chronic sinopulmonary infections. Two of the three patients had absolute IgA deficiency while the third had a partial IgA deficiency. The associated conditions found in these three patients were deficiencies of an IgG subclass, allergic rhinitis and lupus nephritis. The youngest child (5 years old boy with lupus nephritis) expired from Pneumocystis carrinii pneumonia complicated with adult respiratory distress syndrome.