Brazilian report on primary immunodeficiencies in children: 166 cases studied over a follow-up time of 15 years.

One hundred sixty-six cases of primary immunodeficiency diseases (PID) (95 males, 71 females), diagnosed according to WHO criteria, have been registered at the Children's Hospital, University of São Paulo, Brazil. The following frequencies were found: predominantly humoral defects, 60.8% (n = 101); T cell defects, 4.9% (n = 8); combined ID, 9.6% (n = 16); phagocyte disorders, 18.7% (n = 31); and complement deficiencies, 6% (n = 10). IgA deficiency was the most frequent disorder (n = 60), followed by transient hypogammaglobulinemia (n = 14), chronic granulomatous disease (n = 14), and X-linked agammaglobulinemia (n = 9). In comparison to other (national) reports, we observed higher relative frequencies of phagocyte and complement deficiencies. Recurrent infections were the cause of death in 12.7%. Allergic symptoms were observed in 41%, mainly in IgA-deficient, hypogammaglobulinemic, or hyper-IgE patients, and autoimmune disorders in 5%, predominantly in IgA and complement deficiencies. Five patients suffered from BCG dissemination; two of them died. This is the first Brazilian report on PID over an observation time of 15 years.