Monoclonal Gammopathies After Renal Transplantation: A Single-center Study.

INTRODUCTION: Plasma cell disorders (PCDs) are clonal plasma cell disorders that include conditions such as monoclonal gammopathy of undetermined significance (MGUS), monoclonal gammopathy of renal significance (MGRS), multiple myeloma (MM), smoldering MM (SMM), solitary plasmacytoma, and light-chain (AL) amyloidosis. The risk factors associated with and the clinical course of PCDs after renal transplantation is not well established although immunosuppressive protocols may impact the incidence and natural history of PCDs posttransplant. PATIENTS AND METHODS: This single-center retrospective study evaluated patients with a history of renal transplant who developed a PCD between January 1, 2014-December 31, 2018. RESULT: A total of 41 patients met the inclusion criteria including 29 with MGUS and 12 with symptomatic PCD (4 with MM, 2 with SMM, 4 with MGRS, 1 with AL amyloidosis, and 1 with solitary plasmacytoma). The median follow-up of survivors was 41.6 months. Three patients (1 with MGUS and 2 with MGRS) progressed to MM during the follow-up period. There was a male preponderance in both groups. There was no correlation between the donor and immunosuppressive regimen and the development of a PCD. Patients with symptomatic PCD had higher serum creatinine and M-protein levels at diagnosis and higher free light chain ratio and plasma cell burden. There was also a higher percentage of allograft failure noted in the symptomatic PCD subset 50% (n = 6), whereas only 23% (n = 7) of patients had allograft failure in the MGUS group. CONCLUSION: This study shows the importance of considering monoclonal gammopathy in the differential of renal dysfunction after kidney transplant and the need to follow these patients closely to monitor for progression to symptomatic PCD.

Successful treatment of BK viremia using reduction in immunosuppression without antiviral therapy.

BACKGROUND: Treatment of BK virus (BKV) infection in renal transplant recipients remains controversial. This retrospective analysis evaluated efficacy and safety of reducing immunosuppression without antiviral therapy. METHODS: This single center analysis included 24 patients diagnosed with BK viremia between September 2001 and December 2003. Sixteen patients (66%) presented with BKV nephritis and eight patients (34%) presented with viremia without evidence of nephritis on renal biopsy. RESULTS: At time of diagnosis, mean plasma BKV DNA (copies/mL) was 460,409 (range 10,205-1,920,691). Mean doses reduction of mycophenolate mofetil and tacrolimus were 44% and 41%, respectively, from time of diagnosis of BKV infection to complete resolution of viremia. A decline in BK viral load was noticed within 15 to 30 days, with successful elimination of viremia over a mean period of 5.8 months (range, 1-9.5). Mean serum creatinine at time of diagnosis of BK viremia was 1.8 mg/dL (range, 1.2-2.8). Mean follow-up period is 30.9 months postdiagnosis. At the most recent visit, serum creatinine was 2.0 mg/dL (range, 1.0-3.6) (P=0.14). With reduction in immunosuppressive therapy, three patients (13%) developed acute cellular rejection and were treated successfully with intravenous bolus steroids. During follow-up, one patient had a relapse of BKV nephritis during pregnancy and lost her graft. After mean follow-up period of 43.5 months posttransplantation, all 24 patients are alive and 23 have a functioning graft. Seventeen patients (71%) have stable or improved graft function. CONCLUSION: Our analysis shows that reduction in immunosuppression therapy alone results in clearance of the BK viremia with good long-term outcome.