Peripheral blood and bronchoalveolar leukocyte profile in lung transplant recipients and their changes according to immunosuppressive regimen: A single-center experience

Background: After lung transplantation (LuTX), lower respiratory tract infections (LRTI) and acute cellular rejection (ACR) are associated with changes in peripheral blood and bronchoalveolar lavage fluid mononuclear cell profile (PBMC and BALIC). PBMC is also influenced by immunosuppressive regimen and its changes with postoperative time. First-year PBMC and BALIC changes were evaluated in this study with rabbit anti-thymocyte globulin (ATG) and alemtuzumab (AL) induction therapy. Methods: In total, 64 LuTX recipients were included, 53 of them received AL and 11 ATG as induction therapy. PBMC and BALIC were examined routinely and in cases suspicious of infection and/or rejection. A PBMC- and BALIC-based algorithm for infection and rejection prediction was also tested. Results: In the AL group, peripheral blood lymphocyte and basophil cell numbers were significantly reduced, while the neutrophil cell number elevation during LRTI was significantly higher compared to the control. Early postoperative measurements showed a lower BALIC lymphocyte count. The algorithm had 17% sensitivity and 94% specificity for ACR in all patients and 33% sensitivity and 95% specificity for ACR with coexisting LRTI. Conclusion: BALIC is not significantly influenced by the immunosuppressive regimen. PBMC- and BALIC-based algorithm may improve the differential diagnosis of ACR.