Kidney transplantation for active multiple myeloma or smoldering myeloma: a case-control study

Background. The increased survival of patients with multiple myeloma (MM) raises the question of kidney transplantation (KT) in patients with end-stage renal disease (ESRD). Methods. We included 13 patients with MM or smoldering myeloma (SMM) and ESRD transplanted between 2007 and 2015, including 7 MM with cast nephropathy, 3 with MM-associated amyloid light chain amyloidosis or light chain deposition disease and 3 SMM and compared them with 65 control-matched kidney-transplanted patients. Nine of the MM patients with KT were also compared with 63 matched MM patients on haemodialysis. Results. Pre-transplantation parameters were comparable, except for the duration of renal replacement therapy (57.8 versus 37.0 months; P=0.029) in MM versus control patients, respectively. The median follow-up post-KT was 44.4 versus 36.4 months (P=0.40). The median MM graft and patient survival were 80.1 and 117.2 months, respectively, and were not significantly different from control patients, although mortality tended to be higher in the 10 symptomatic MM patients (P=0.059). MM patients had significantly more viral and fungal infections and immunosuppressive maintenance therapy modifications while they received lower induction therapy. Two MM patients relapsed and two SMM cases evolved to MM after KT. Three cast nephropathies occurred, two of them leading to ESRD. Moreover, survival of MM with KT increased relative to control haemodialysed patients (P=0.002). Conclusions. Selected MM patients may benefit from KT but need careful surveillance in the case of KT complications and MM evolution.