immunology allergic disorders
Selective IgA Deficiency
Key Points
Selective IgA deficiency is the most common primary immunodeficiency. Patients may be asymptomatic or have recurrent infections or autoimmune disorders; some develop CVID over time, but in others, selective IgA deficiency spontaneously resolves. Suspect selective IgA deficiency if patients have anaphylactic reactions to transfusions, take drugs that lead to IgA deficiency, or have recurrent infections or a suggestive family history. Confirm the diagnosis by measuring Ig levels and antibody titers after vaccines are given; an IgA level < 7mg/dL (< 70 mg/L) and normal IgG and IgM levels and antibody titers are diagnostic. Give antibiotics as needed and, in severe cases, prophylactically. Avoid giving patients blood products or immune globulin that contain more than minimal amounts of IgA. 