Kinetics of T-lymphocyte subsets and posttransplant opportunistic infections in heart and kidney transplant recipients.

BACKGROUND: The potential use of T-lymphocyte measurements as infection risk markers after solid organ transplant has not been fully investigated. We analyzed the kinetics of T-lymphocyte subsets within the first 8 months posttransplamt and their correlation with opportunistic infections (Ols) in solid organ transplant recipients. METHODS: Serial measurement of CD4 and CD8 T cells was performed retrospectively in 48 heart treansplant recipients (HTR) and 42 kidney transplant recipients (KTR): Generalized estimating equation models were used to analyze longitudinal data separetely for HTR and KTR. RESULTS: An initial CD4 T-cell drop (at months 1 and 2, in HTR and KTR, respectively) coincided with the peak of Ols. HTR with a low nadir CD4 T-cell count (< 200/uL) showed poor CD4 T-cell recovery (175 + 277 cells/uL9 at baseline vs 242 + 99 cells/ul at months 8) and their CD8 T cells increased from 153 + 194 cells/ul at baseline to 601 + 399 cells/ul at month 8. KTR with a low nadir CD4 T-cell count ( < 200/ul) showed a modest CD4 T-cell recovery (138 + 46 cells/ul) at baseline vs 440 + 448 cells/ul at month 8), and their CD8 T cells increased from 90 + 41 cells/ul at baseline to 450 + 242 cells /ul at month 8. HTR developint Ols had lower CD4 (P<0.001) and CD8 T cells (P=0.001) than those without infections, whereas in KTR the risk for Ols seemed restricted to patients with low CD8 T cell. HTR with Ols had a low CD4/CD8 T-cell ratio, whereas KTR had a hith CD4/CD8 T-cell ratio. CONCLUSIONS: Determination of T-lymphocyte subsets is a simple and effective parameter to identify patients at risk of develping Ols.