Kidney Transplantation in Monoclonal Immunoglobulin Deposition Disease: A Report of 6 Cases.

Monoclonal immunoglobulin deposition disease (MIDD) usually leads to kidney failure. Treatment of patients with a bortezomib-based regimen followed by autologous stem cell transplantation (SCT) has been increasingly used, with improvements in the response rates and allograft outcomes in kidney transplant recipients. The objective of this report was to analyze the outcomes of 6 patients who underwent kidney transplantation in our institution after treatment of MIDD between 2010 and 2019. Monoclonal immunoglobulin deposition disease was initially treated with bortezomib-based therapy followed by high-dose melphalan and autologous SCT with complete hematologic response, although all patients remained on dialysis. During a median follow-up of 20.5 months from kidney transplant (54 months from SCT), 1 patient experienced hematologic relapse and 2 had hematologic progression (one of them with MIDD relapse in the allograft) requiring treatment. The patient with organ relapse received daratumumab monotherapy, achieving complete hematologic response but with graft failure. The other 5 patients had functional grafts with median serum creatinine 1.68 mg/dL. These results support that, in patients with MIDD and sustained complete hematologic response, a kidney transplant can be considered. The optimal approach to treatment of hematologic relapse or recurrence of MIDD after kidney transplant remains to be determined.