Treatment-resistant recurrent membranoproliferative glomerulonephritis in renal allograft responding to rituximab: case report.

We report a case of idiopathic membranoproliferative glomerulonephritis (MPGN) recurring 2 years after a living-unrelated kidney transplantation. The disease was refractory to intravenous immunoglobulin and plasmapheresis. Treatment with 2 doses of rituximab resulted in remission of the disease. The disease relapsed 18 months later after an episode of cytomegalovirus pneumonitis. After treatment of the pneumonitis, a lung biopsy was performed owing to persistent chest symptoms, which revealed bronchiolitis obliterans with organizing pneumonia. Bone marrow examination and culture revealed presence of acid-fast bacilli, and culture grew Mycobacterium tuberculosis. A repeated course of rituximab was withheld because of infection with tuberculosis, the patient's chest symptoms, and rare reports of noninfectious lung disease after the use of rituximab. The patient continues to have proteinuria with impaired kidney function.