Impact of Induction Immunosuppressants on T Lymphocyte Subsets after Kidney Transplantation: A Prospective Observational Study with Focus on Anti-Thymocyte Globulin and Basiliximab Induction Therapies

Induction immunosuppressive therapy for kidney transplant recipients (KTRs) primarily includes interleukin-2 receptor antagonists, such as basiliximab (BXM) or lymphocyte-depleting agents, and anti-thymocyte globulin (ATG). This study aimed to investigate their effects on T cell dynamics during the early post-transplantation period. This prospective observational study included 157 KTRs. Peripheral blood samples were collected from each patient within 5 days before and 4 and 12 weeks after transplantation. Flow cytometric analysis was performed to assess various T cell subsets whose changes were then analyzed. In the ATG group, CD4(+) T cell expression decreased significantly compared with that in the BXM group. However, CD4(+)CD161(+) and CD4(+)CD25(+)CD127low T cell expression levels increased significantly. In the CD8(+) T cell subset, a decrease in CD8(+)CD28nullCD57(+) and CD8(+)CCR7(+) T cell expression was observed in the ATG group. However, among patients diagnosed with biopsy-proven acute rejection, T cell subset expression did not significantly differ relative to non-rejection cases. In conclusion, ATG induction therapy resulted in more pronounced changes in T lymphocyte subsets than BXM induction, with increased CD4(+)CD161(+) and CD4(+)CD25(+)CD127low T cells and an early decrease in CD8(+)CD28nullCD57(+) and CD8(+)CCR7(+) T cells, some of which are associated with acute rejection.