The rationale and evidence base for the direct removal of serum-free light chains in the management of myeloma kidney

Renal Involvement in Multiple Myeloma

Multiple myeloma (MM) is a plasma cell disorder that represents almost 10% of haematologic malignancies. Renal impairment, one of the most common complications of MM that occurs in 20–50% of patients, can present in a variety of forms and is associated with increased mortality. Myeloma cast nephropathy is the most common cause of kidney disease in MM patients, presenting as acute kidney injury in the majority of patients. The recent introduction of new chemotherapy agents, autologous stem cell transplantation, and the development of novel techniques of light chain removal have been associated with improved renal and patient outcomes in MM patients. Nevertheless, dialysis-dependent patients with MM have higher mortality than other dialysis patients and may be considered for kidney transplantation only if sustained remission has been achieved and sustained for at least 3 years, bearing in mind the risk of disease recurrence. The authors review the most frequent renal manifestations associated with MM, namely myeloma cast nephropathy, light-chain amyloidosis, and monoclonal immunoglobulin deposition disease, focussing on the therapeutic options for acute and chronic kidney disease.

Plasmapheresis in cast nephropathy: yes or no?

PURPOSE OF REVIEW

Renal failure is a frequent complication of multiple myeloma and portends a poor prognosis. Plasmapheresis has been suggested as an adjunct to chemotherapy to halt or reverse renal injury associated with multiple myeloma. The purpose of this article is to review the rationale for using plasmapheresis for this indication and then provide a discussion of the evidence regarding its use.

RECENT FINDINGS

The outcome of patients with multiple myeloma has improved considerably in recent years, mostly owing to the introduction of new highly effective chemotherapeutic agents. However, patients with renal failure who do not recover independent renal function continue to have very poor prognosis. Recent evidence now indicates that an early and sustained reduction in circulating free light chains (FLCs) is associated with improved renal recovery in patients with myeloma kidney. Extracorporeal removal of FLCs with plasmapheresis, or other techniques, can achieve rapid and sustained reduction in serum FLC concentration in patients with acute myeloma kidney. Unfortunately, there is currently no convincing evidence in the literature that the addition of mechanical removal of FLC to standard chemotherapy translates into clinical benefits for patients.

SUMMARY

Plasmapheresis is theoretically attractive as a means of rapidly lowering serum FLC burden in the hope of reducing nephrotoxicity in patients with multiple myeloma. However, the role of plasmapheresis in improving renal prognosis and patient survival remains to be demonstrated.