CD40LG and B-cell chronic lymphocytic leukemia: In the CLL group, we observed a decrease below the normal range for age in at least one of the immunoglobulin classes in 38/59 (64.4%) CLL patients: IgG < 7.3 g/L in 18/59 (30.5%) patients; IgA < 0.8 g/L in 27/59 (45.7%) patients; and IgM < 0.4 g/L 28/59 (47.5%) patients.