Membranous nephropathy in a 13-year-old boy with common variable immunodeficiency.

Various forms of hypogammaglobulinemia can occur in patients with autoimmune diseases and vice versa. We report a 13-yr-old boy with membranous nephropathy and common variable immunodeficiency. He presented with the nephrotic syndrome, pneumonia with bronchiectasis, and profound hypogammaglobulinemia. Renal biopsy showed diffusely thickened glomerular capillary walls with 'spikes' suggesting a membranous nephropathy. Secondary causes were ruled out by laboratory studies; however, heavy proteinuria persisted with steroid therapy. Cyclosporine and intravenous immunoglobulin were added, and the patient was discharged with decreased proteinuria. Hypogammaglobulinemia may have a deleterious impact on the immune dysregulation in some patients with membranous nephropathy.