Sepsis after renal transplantation: Clinical, immunological, and microbiological risk factors

Background As immunosuppressive therapy and allograft survival have improved, the increased incidence of sepsis has become a major hurdle of disease‐free survival after renal transplantation. Methods We identified 112 of 957 kidney transplant recipients ( KTR s) with sepsis. In all, 31 KTR s developed severe sepsis or septic shock, and 30 KTR s died from sepsis. KTR s without sepsis were used for comparison. CMV ‐specific and alloreactive T cells were measured using an interferon‐γ Elispot assay. The extent of immunosuppression was quantified by lymphocyte subpopulations. Results Five‐year patient survival was 70.3% with sepsis compared to 88.2% without ( P <.001). Five‐year estimated glomerular filtration rate was lower in KTR s developing sepsis ( P <.001). Upon multivariate analysis, diabetes, lymphocyte‐depleting induction, donor age, CMV replication, and acute rejection increased the risk of sepsis ( P <.05). Age, diabetes, underweight/obesity, and pneumonia as site of infection were predictive factors of mortality ( P <.05). Early‐onset sepsis was associated with decreased CD 3+ and CD 4+ T cells pre‐transplantation ( P <.05). Impaired CMV ‐specific cellular immunity pre‐transplantation was associated with CMV replication and early‐onset sepsis ( P <.05). High frequencies of alloreactive T cells were associated with acute rejection, lymphocyte‐depleting rejection treatment, and early‐onset sepsis ( P <.05). Conclusion KTR s developing sepsis show inferior patient survival and allograft function. Identified risk factors and differences in lymphocyte counts, CMV ‐specific immunity, and alloreactivity may prove useful to identify KTR s at increased risk.