Entry Criteria: The inclusion criteria are a new diagnosis of multiple myeloma and progressive acute kidney failure. The former is defined as a bone marrow aspirate with > 10% plasma cells and a monoclonal light chain in the urine, plasma or renal tissue. The latter is defined as a serum creatinine > 200 mmol/L with a rise > 50 mmol/L in the preceding two weeks despite correction of hypercalcemia, hypovolemia and metabolic acidosis as required in a patient with a normal sized kidney on renal ultrasound.