Defective B-cell and regulatory T-cell function in Wiskott-Aldrich syndrome.

We report two Chinese boys with Wiskott-Aldrich syndrome presenting with gastro-intestinal bleeding, eczema and recurrent infection. They had thrombocytopenia and the mean platelet volume was small. Serum IgG and IgA were elevated and lymphocyte proliferation in response to phytohaemagglutinin, concanavalin A and pokeweed mitogen was defective. Despite documented herpes simplex virus type 1 and cytomegalovirus infection in one patient, he did not mount any humoral response. The generation of antibody-secreting cells in response to pokeweed mitogen was markedly defective in a plaque-forming cell assay. Both patients' regulatory T-cell and B-cell functions were defective in this assay. The genetic defect in Wiskott-Aldrich syndrome therefore affects T-cells, B-cells and platelets.