Sepsis is associated with lack of monocyte HLA-DR expression recovery without modulating T-cell reconstitution after lung transplantation

Abstract Background Immunosuppressive strategy targets mainly adaptive immunity after solid organ transplantation. We assessed the influence of early post-operative sepsis on T cell and monocyte reconstitution in anti-thymocyte globulin (ATG)-treated lung transplant recipients. Methods We retrospectively included recipients who underwent a first lung transplant at our Lung Transplant Center (Marseille, France) between July 2011 and February 2013. Peripheral blood T-lymphocyte subset counts and monocyte HLA-DR (mHLA-DR) expression routinely performed by flow cytometry within 60 days post-transplant were analyzed. We compared the immune kinetics of patients who did or did not develop sepsis during the post-operative intensive care unit stay. Results Among the 37 recipients included, 19 patients (51%) developed at least one episode of sepsis. At the ICU admission, septic recipients had higher SOFA score (9 [7.5–9] versus 6 [ [4] , [5] , [6] , [7] ]), p = .01), higher primary graft dysfunction score (1.4 ± 1.4 versus 0.3 ± 0.7, p = .008) and more frequent use of ECMO (47% versus 0%, p = .003). Whereas both groups had similar T-lymphocytes reconstitution in the post-operative period, mHLA-DR reconstitution was dramatically affected in septic patients after day 14, median mHLA-DR expression at 2.3 MFI [1.3–3.5] in the septic versus 8.0 MFI [5.1–10.5] in the non-septic group, p = .02. Conclusion We found that sepsis is negatively correlated with the mHLA-DR expression but not adaptive T cell immune reconstitution. This finding highlights the importance of immunomonitoring after lung transplantation and questions the strategy of a lower immunosuppression therapy in context of sepsis.