The patient with myeloma

Renal impairment is a common feature of multiple myeloma and often the presenting symptom of a patient with symptomatic myeloma. ‘Myeloma kidney’ results from the excess of immunoglobulin light chains which form aggregates and casts that result in tubular obstruction; however, light chains may cause renal damage with a variety of mechanisms, which often may coexist in the same patient. The presence of significant renal dysfunction in a patient with myeloma is associated with a risk for significant complications, including early death. Myeloma kidney is usually associated with high tumour burden and high rates of paraprotein production. Patients with renal impairment should be managed immediately with appropriate antimyeloma therapy and supported vigorously. New drugs such as bortezomib are probably the most effective therapies for patients with renal dysfunction and may improve renal function in a significant proportion of patients with myeloma-related renal impairment, especially with dexamethasone at high doses. Other drugs such as thalidomide or lenalidomide may also be helpful in certain patients. Direct removal of the toxic free light chains may improve outcomes in some patients, but randomized studies are still ongoing. The role of plasmapheresis has not been established. Autologous stem cell transplantation, with appropriate dose adjustments for high-dose melphalan should be offered in eligible patients, even those on dialysis, although this procedure may be associated with a higher risk of toxicity in patients with more severe renal dysfunction. Renal transplantation may be an option for selected patients who have responded well to therapy.