Kidney Transplantation in Patients with Multiple Myeloma: Current Evidence, Challenges, and Future Directions.

Renal involvement is an important complication of multiple myeloma (MM) and is related not only to worse clinical outcomes but also to lower quality of life, particularly when progressing to end-stage renal disease. Traditionally, MM patients were not considered eligible for kidney transplant; however, these paradigms are changing. The new era of MM therapies brought proteasome inhibitors, immunomodulatory drugs, monoclonal antibodies, and, most recently, cellular therapies, leading to longer survival and sustained hematological responses. Knowledge of cytogenetic abnormalities has helped risk stratification. These advances result in the identification of patients who achieve durable remission and may benefit from kidney transplant programs as an option for renal replacement therapy. Reported 5-year allograft survival ranges from 50 to 66%, progression-free survival is 44%, and overall survival is 61%, depending on pre-transplant remission depth. This review summarizes updated available evidence regarding kidney transplants in MM, proposes evidence-based eligibility criteria for kidney transplantation in this population, and outlines therapeutic strategies for long-term follow-up. In conclusion, kidney transplantation may be a feasible option for carefully selected MM patients achieving deep and sustained remission, though prospective data are still needed.