High dose chemotherapy in light chain or light and heavy chain deposition disease.

BACKGROUND Conventional chemotherapy for myeloma yield unsatisfactory results in light and/or heavy chain deposition disease [(H)CDD] Because of the well-established dose-response effect of high dose melphalan in multiple myeloma, aiming to dramatically reduce the pathogenic monoclonal immunoglobulin (MIg) level, high dose therapy is a tempting alternative approach. METHODS We treated 11 young patients with L(H)CDD by high dose therapy with the support of autologous blood stem cell transplantation. All had renal symptoms, including four who required dialysis and seven who had various, mainly cardiac, extrarenal manifestations. RESULTS No toxic deaths occurred. A decrease in the MIg level was observed in eight patients, with complete disappearance from serum and urine in six cases. Improvement in manifestations related to MIg deposits were observed in six patients, including renal, cardiac, and hepatic responses in 4/11, 4/4, and 2/2 cases, respectively. Histologic regression of MIg deposits was documented in cardiac, hepatic, and skin biopsies. In contrast, examination of the kidney still showed light chain deposits in one patient who had renal transplantation 3 years after high dose therapy, at a time when he was in persisting remission. Within a median follow-up of 51 months, three patients were retreated because of multiple myeloma relapse, of whom one died and one required hemodialysis, and renal function secondarily deteriorated in a patient who had resistant multiple myeloma. Otherwise, no manifestations related to MIg deposits occurred or recurred in any patient. CONCLUSION Present results of this retrospective study argue in favor of a benefit of high dose therapy with stem cell support in young patients with L(H)CDD.