Conversion from tacrolimus‐mycophenolate mofetil to tacrolimus‐ mTOR immunosuppression after kidney‐pancreas transplantation reduces the incidence of both BK and CMV viremia

Background We sought to determine whether conversion from tacrolimus/mycophenolate mofetil ( TAC ‐ MMF ) into tacrolimus/ mTOR inhibitor ( TAC ‐ mTOR ) immunosuppression would reduce the incidences of BK and CMV viremia after kidney/pancreas ( KP ) transplantation. Methods In this single‐center review, the TAC ‐ mTOR cohort (n = 39) was converted at 1 month post‐transplant to an mTOR inhibitor and reduced‐dose tacrolimus. Outcomes were compared to a cohort of KP recipients (n = 40) maintained on TAC ‐MMF. Results At 3 years post‐transplant, KP survivals and incidences of kidney/pancreas rejection were equivalent between mTOR and MMF ‐treated cohorts. ( P  = ns). BK viremia‐free survival was better for the mTOR vs MMF ‐treated group ( P  = .004). In multivariate analysis, MMF vs mTOR immunosuppression was an independent risk factor for BK viremia (hazard ratio 12.27, P  = .02). Similarly, mTOR ‐treated recipients displayed better CMV infection‐free survival compared to the MMF ‐treated cohort ( P  = .01). MMF vs mTOR immunosuppression (hazard ratio 18.77, P  = .001) and older recipient age (hazard ratio 1.13 per year, P  = .006) were independent risk factors for CMV viremia. Mean estimated GFR and HgbA1c levels were equivalent between groups at 1, 2, and 3 years post‐transplantation. Conclusion Conversion from TAC / MMF into TAC / mTOR immunosuppression after KP transplantation reduced the incidences of BK and CMV viremia with an equivalent risk of acute rejection and similar renal/pancreas function.