Lambda light chain myeloma with oliguric cast nephropathy and remission with bortezomib, doxorubicin and dexamethasone

Abstract

Cast nephropathy is one of the major causes of renal failure in patients with multiple myeloma resulting from precipitation of free light chains inside the tubules. Timely diagnosis and treatment confers a better prognosis though around 10% of patients with cast nephropathy remain dialysis dependent in spite of treatment. We report the clinical course and outcome of a patient presenting with acute kidney injury and oliguria, preceded by acute gastroenteritis and intake of Chinese medications and dialysis dependent state for eight weeks. Kidney biopsy revealed cast nephropathy with lambda light chain restriction and severe tubular injury. Serum protein electrophoresis was normal with no "M spike" but serum free light chain ratio was altered with very high lambda and normal kappa light chain levels. Bone marrow biopsy showed >85% atypical plasma cells. Haemodialysis was continued and chemotherapy with bortezomib, doxorubicin and dexamethasone was started. Kidney function gradually improved with discontinuation of dialysis after 1 month and complete remission of acute kidney injury and myeloma in 4 months of chemotherapy.