TREATMENT

Treatment of myeloma cast nephropathy centers on volume expansion, which reduces intratubular cast concentration, as well as chemotherapy (and sometimes plasmapheresis), which reduces serum free light chain concentration. The role of plasmapheresis is controversial. One study of patients with biopsy-proven myeloma cast nephropathy found that plasmapheresis led to a 50% reduction in serum creatinine concentration, as well as dialysis independence, in those who experienced a more than 50% reduction in the serum free light chain concentration. Other studies, however, have shown no benefit. Dialysis is offered to patients who have advanced renal failure as a supportive measure, but it does not influence the course of the disease.

PROGNOSIS

Survival in patients with multiple myeloma is inversely correlated with serum creatinine concentration at presentation, as shown in a study from the 1980s that found a median survival of 44, 18, and 4.3 months in patients with creatinine less than 1.4, 1.4 to 2.0, and greater than 2.0 mg/dL, respectively. The potential for improvement of renal function in response to treatment correlates best with the degree of tubulointerstitial fibrosis and tubular atrophy on biopsy. Recovery of renal function has been known to occur in patients who require dialysis, occuring up to 3 months after dialysis onset.