Toxoplasma Gondii Serostatus in Heart Transplant Recipients: Is It an Independent Prognostic Factor?

INTRODUCTION AND OBJECTIVES To assess the potential association between recipient Toxoplasma gondii serostatus and outcomes after heart transplant (HT). METHODS We conducted a retrospective single-center study of 657 HT recipients from 1991 to 2015. Survival and the incidence of adverse clinical events of T. gondii-seropositive (n = 481) vs T. gondii-seronegative (n = 176) recipients were compared by means of 2 different multivariable Cox regression models. Model 1 included solely age and sex, and model 2 included other potential confounders. RESULTS Over a median follow-up of 2903 days (interquartile range: 898-4757), 250 seropositive recipients (52%) and 72 seronegative recipients (41%) died. Univariable analysis showed increased posttransplant mortality among T. gondii-seropositive recipients (hazard ratio [HR] = 1.31; 95% confidence interval [95%CI], 1,00-1.70). After multivariable adjustment, the statistical significance of this association was lost (model 1: HR = 1.09; 95%CI, 0.83-1.43; model 2:HR = 1.12; 95%CI, 0.85-1.47). Recipient T. gondii seropositivity was independently associated with an increased risk of acute rejection (model 1: HR = 1.36; 95%CI, 1.06-1.74; model 2: HR = 1.29; 95%CI, 1.01-1.66). Multivariable models showed no statistically significant impact of recipient T. gondii serostatus on the incidence of infection, malignancy, coronary allograft vasculopathy, or the composite outcome of cardiac death or retransplant. No significant association was found between donor-recipient T. gondii serostatus matching and posttransplant outcome. CONCLUSIONS In this study, recipient T. gondii serostatus was not an independent predictor of long-term post-HT outcome.