Acute rejection in heart transplant patients is associated with the presence of committed donor-specific cytotoxic lymphocytes in the graft but not in the blood

Abstract

SUMMARYTn ri(v»-aclivated, committed donor-specific cytotoxic lymphocytes (cCTL) can be propagated and expanded from endomyocardial biopsies (EM B) in I L-2-enriched medium especially during an acute rejection episode. We report hereourefforts to detect these cCTL by the same technique in peripheral blood at the moment of rejection and when no rejection was diagnosed. During or just before rejection, significantly less frequent (/*< 0-01) donor reactive cCTL were found in PBL samples (two out of 20) than in the simultaneously taken EMB samples (13 out of 19). Donor B-LCL and/or thirdparty B-LCL were lysed by 15 PBL samples. Inhibition studies revealed that this lysis was due to LAK-like cylotoxicity. The results show that peripheral blood does not reflect intra-graft events, which is probably the reason for the irreproducible results of diagnosis of rejection by monitoring immunological parameters in the peripheral blood.

Cytomegalovirus hyperimmunoglobulin: mechanisms in allo‐immune response in vitro

“…These in vitro results indicated that antiproliferative effects and induction of apoptosis in CD8+ and NK cells were two clearly independent mechanisms. This observation seems to be of particular interest in the setting of allo‐immmune response as cytotoxic CD8+ cells are known to be primarily responsible for acute allograft rejection [30,31].…”