Epidemiology of cytomegalovirus infection after pancreas transplantation.

Background: Epidemiology of cytomegalovirus (CMV) infection has not been comprehensively studied after all three types of pancreas transplant (PT) including simultaneous pancreas-kidney transplantation (SPK), pancreas transplantation alone (PTA), and pancreas after kidney transplantation (PAK).

Methods: We evaluated incidence, risk factors, and outcomes of CMV infection after pancreas transplant at our center from January 1, 1998, to December 31, 2009.

Results: The study cohort included 252 recipients (SPK 60, PTA 71, and PAK 121), 53% men, age 43.9±9 years, followed for 6.3 (interquartile range 3-9) years. CMV serostatus was donor (D) seropositive and recipient (R) seronegative (D+/R-) (27%), D+/R+ (32%), D-/R+ (18%), D-/R- (23%), and one unknown/R+ (0.4%). Two hundred six (82%) patients received CMV prophylaxis. Twelve patients experienced CMV viremia, whereas 31 developed CMV disease. The cumulative incidence of CMV infection (viremia and disease) was 15%, 17%, and 20% at 1, 5, and 10 years, respectively, with no events after 10 years. It was higher in D+/R- group (P<0.004) and patients with kidney graft failure (P=0.036). The variables significantly associated with pancreas graft failure were transplant type (PTA vs. SPK, hazard ratio [HR]=2.29, P=0.020; PAK vs. SPK, HR=2.73, P=0.003) and acute pancreas rejection (HR=2.47, P<0.001). In multivariable mortality model, increased age (P<0.001) and pancreas graft failure (P<0.001) were associated with an increased risk of death, whereas CMV infection (P=0.036) was associated with a borderline decreased risk.

Conclusions: CMV remains a common cause of clinical illness, particularly among the CMV D+/R- mismatched and patients with kidney graft failure. Marginal association was observed between CMV infection and a lower risk of death, but not with allograft failure.