Polyomavirus and cytomegalovirus infections are risk factors for grafts loss in simultaneous pancreas and kidney transplant

BACKGROUND: Published literature on predictors of polyomavirus (BKV) and cytomegalovirus (CMV) infections in simultaneous pancreas and kidney (SPK) transplant and their impact on allograft outcomes remain sparse. We hypothesize that BKV and CMV viremia infections decrease allograft survival in SPK. Identifying modifiable predictors of BKV and CMV may help tailor immunosuppression and improve allograft survival. METHODS: All SPK recipients at our institution between January 2000 and April 2016 were included (n = 757). Thirty-nine recipients had BKV only and 25 had CMV only, and infection occurred at median follow-up times of 217 and 163 days, respectively. Event density sampling was used to match recipients with BKV or CMV to up to 10 recipients without infection by age, sex, and HLA mismatch status, and these were followed for a median of 4.3 years after infection. RESULTS: Older age (HR 1.49 for each decade; 95% CI: 0.95, 2.35; P = .083) and tacrolimus use (HR 20.6; 95% CI: 2.37, 179.53; P = .006) were associated with increased incidence of BKV, but not CMV, infection. Both BKV and CMV infections were associated with increased risk of allograft failure for both pancreas (BKV [HR 2.17; 95% CI 1.47, 3.208; P = .000], CMV [HR 1.7; 95% CI 1.077, 2.687; P = .023]) and kidney (BKV [HR 2.65; 95% CI 1.765, 3.984; P = .000], CMV [HR 2.07; 95% CI 1.295, 3.308; P = .002]). CONCLUSION: Older age at time of transplant and tacrolimus may help predict BKV infection in SPK recipients.