Pretransplant lymphopenia is a novel prognostic factor in cytomegalovirus and noncytomegalovirus invasive infections after liver transplantation.

Infection after liver transplantation (LT) remains a leading cause of morbidity and mortality. The risk of infection after LT is highest in those who are most immunosuppressed, but to date, no standard blood marker of one's degree of immunosuppression or risk index has been established. The purpose of this study was to determine whether pretransplant lymphopenia (absolute lymphocyte count < 500 cells/mm3 within 24 hours before LT) is a candidate marker of immunosuppression and could be useful in predicting the risk of cytomegalovirus (CMV) disease and non-CMV invasive infections after LT. Data were extracted from medical records for all primary, solitary LT procedures performed at Tufts Medical Center from 1999 to 2009. Two hundred seventy-six patients had sufficient data to be included in the analysis. Among these patients, 52% developed CMV or non-CMV invasive infections within 5 years of LT. Within 2 years, 23 (8%) had CMV disease, and 103 (37%) at least 1 non-CMV invasive infection. More lymphopenic patients than nonlymphopenic patients developed CMV (21% versus 4%, P < 0.001) and non-CMV invasive infections (50% versus 33%, P = 0.02). In a multivariate survival analysis, pretransplant lymphopenia was the strongest independent predictor of CMV disease [hazard ratio (HR) = 5.52, 95% confidence interval (CI) = 2.31-13.1, P = 0.001] after adjustments for known risk factors, including CMV serostatus (HR = 4.72, 95% CI = 2.01-11.1, P < 0.001). Both pretransplant lymphopenia (HR = 1.64, 95% CI = 1.14-2.53, P = 0.03) and CMV (HR = 2.93, 95% CI = 1.23-6.92, P = 0.02) independently predicted non-CMV infections. Our results suggest that pretransplant lymphopenia is a novel independent predictor of both CMV disease and non-CMV invasive infections after LT and is a candidate marker of immunosuppression in LT recipients.