Kidney injury is a relatively common problem in patients with multiple myeloma. Approximately 20 percent of patients have impaired renal function (defined as an increase in the serum creatinine to greater than 2.0 mg/dL [177 micromol/L]) at presentation . Renal disease most often occurs in patients with a high tumor burden  and can evolve as either an acute or chronic disorder.
Multiple etiologies have been attributed to acute kidney injury (AKI) in patients with multiple myeloma. Hypercalcemia; volume depletion; hyperuricemia; hyperviscosity (rare); and toxicity due to intravenous radiocontrast media, nonsteroidal antiinflammatory agents (NSAIDs), or angiotensin-converting enzyme (ACE) inhibitors or receptor blockers (ARBs) all may contribute [2-6].
Myeloma cast nephropathy occurs most often in patients with high rates of production and excretion of immunoglobulin free light chains, which may be toxic to the tubules and form obstructing tubular casts, particularly if the patient is volume depleted . Other common renal lesions include primary amyloidosis or light chain deposition disease (LCDD) [2,7]. Concurrent presence of both myeloma cast nephropathy and either amyloidosis or LCDD can occur, but is unusual [7-9].
Patients with amyloidosis or LCDD may not have significantly reduced kidney function at the time of presentation (although renal failure may occur if amyloidosis or LCDD is not recognized and is left untreated) and are treated with chemotherapy directed against the abnormal plasma cell clone. One of these two disorders should be suspected when there are signs of the nephrotic syndrome, including heavy albuminuria, hypoalbuminemia, and edema . Renal vein thrombosis may rarely be present in patients with nephrotic syndrome, although its contribution to renal failure in multiple myeloma is not well described. The treatment of hypercoagulability associated with the nephrotic syndrome is discussed separately. (See "Renal vein thrombosis and hypercoagulable state in nephrotic syndrome".)
This topic review will discuss the treatment of typical causes of renal failure in patients with multiple myeloma, with a focus on myeloma cast nephropathy. The types of renal disease in multiple myeloma, the pathogenesis of myeloma cast nephropathy, amyloidosis and light and heavy chain deposition diseases, and the treatment of multiple myeloma are discussed separately. (See "Types of renal disease in multiple myeloma" and "Pathogenesis and diagnosis of myeloma cast nephropathy (myeloma kidney)" and "Pathogenesis of immunoglobulin light chain (AL) amyloidosis and light and heavy chain deposition diseases" and "Determination of initial therapy in patients with multiple myeloma".)