Rituximab treatment for a patient with type I cryoglobulinemic glomerulonephritis.

BACKGROUND: A 74-year-old woman with a history of type I cryoglobulinemia with glomerulonephritis that had been successfully treated with plasmapheresis and cyclophosphamide approximately 9 years earlier presented with hemoptysis and mediastinal lymphadenopathy. Evaluation revealed the reappearance of cryoglobulins and nephrotic-range proteinuria. In addition, the patient's serum creatinine level, which had been stable for approximately 9 years after her first treatment, had increased from 79.2 micromol/l (0.9 mg/dl) to 281.6 micromol/l (3.2 mg/dl) over 6 months. INVESTIGATIONS: Physical examination, serum and urine laboratory analyses, CT scan, mediastinoscopy with lymph node biopsy, bone marrow biopsy, flow cytometry analysis of bone marrow, peripheral blood and lymph node tissue, and percutaneous ultrasound-guided renal biopsy. DIAGNOSIS: Type I cryoglobulinemic glomerulonephritis associated with a CD20(+) lymphoid disorder. MANAGEMENT: One plasmapheresis treatment, one dose of cyclophosphamide, and four weekly cycles of rituximab.