[Nephrotic syndrome associated with B-cell chronic lymphocytic leukemia successfully treated with interferon-alpha].

A 31-year-old man was admitted for investigation of proteinuria and hematuria. Physical examination on admission revealed systemic lymphoadenopathy, no hepatosplenomegaly, and ankle edema. Hemoglobin was 14.3 g/dl, platelet 21.4 x 10(4)/microliters and WBC 40,800/microliters which contained 86% mature lymphoid cells. Immunological phenotyping of peripheral lymphoid cells gave positive reactions for CD19, and CD20, and negative reaction for smlg. Urinary protein excretion was 8.3 g/dl in 24h. Serum total protein was 4.1 g/dl with albumin of 2.5 g/dl. Serum IgG was 302 mg/dl, IgA 43 mg/dl, and IgM 56 mg/dl. Renal biopsy showed characteristic features of membranoproliferative glomerulonephritis (MPGN). He was diagnosed as having nephrotic syndrome associated with B-cell chronic lymphocytic leukemia (B-CLL), and was treated with prednisolone and cyclophosphamide without effect. Therefore, he was treated with 18 MU of recombinant-alpha-2a-interferon (IFN-alpha)/day. This treatment resulted in almost normal WBC and differential counts, and urinary protein excretion of 3g in 24h 2 months later. After IFN-alpha treatment was discontinued, WBC count and the amount of urinary protein again increased. He was again treated with IFN-alpha at the dose of 9.0 MU/day three times a week, and is now well without any complaints. This is the first case report in which IFN-alpha was effective in a patient with nephrotic syndrome associated with B-CLL. We think that IFN-alpha therapy is worth trying in similar cases.