Childhood autoimmune cytopenia secondary to unsuspected common variable immunodeficiency.

Immune thrombocytopenic purpura and autoimmune hemolytic anemia are typically idiopathic processes without underlying systemic illness. Four children with autoimmune cytopenia had low immunoglobulin levels that led to the diagnosis of common variable immunodeficiency. Routine screening of immunoglobulins is suggested for children with chronic or recurrent immune thrombocytopenic purpura and autoimmune hemolytic anemia.