Renal failure in multiple myeloma

This report details the case of a 65-year-old man who was diagnosed with multiple myeloma in 2006 and since 2009, has attempted to control the progression of his disease with the most powerful available treatment regimens, including bortezomib-based regimens, for both induction and consolidation therapy followed by autologous stem-cell transplants. Subsequently, because the patient was deemed treatment refractory, treatment with the newly approved carfilzomib was initiated. Coincidentally, the patient developed acute kidney injury, evidenced by tenfold rise in his creatinine levels, 2 weeks after the initiation of carfilzomib. The etiology of his acute kidney injury was unclear; although initially thought to be secondary to volume depletion, this new chemotherapeutic drug could not be excluded as the causative agent given the correlation with the timing of onset. In addition, because carfilzomib was newly approved, there was little documentation on its toxicities, but nephrotoxicity has been noted as a rare side effect. Nevertheless, multiple myeloma is known to damage kidneys, and this patient had light chain disease, kappa type, the form of multiple myeloma that has been shown to most commonly involve the kidneys. An invasive biopsy was indicated to determine the etiology of the patient’s renal failure, as the myeloma could not be excluded, and though the former 2 causes may be reversible, aggressive interventions would be required should the latter have cause his acute kidney injury. Renal failure in multiple myeloma can be attributed to a number of causes, and it is often unclear on presentation what the precipitating factor is, which makes treatment, and thus recovery of renal function a difficult task. The following case details the patient’s clinical presentation and the subsequent investigations and management of his condition, along with a brief discussion of how one can approach and manage renal failure in this patient population.