T-LYMPHOCYTE SUBSETS AND ACTIVATION STATUS IN PATIENTS FOLLOWING LIVER-TRANSPLANTATION

Changes in T-lymphocyte subsets have previously been shown to relate t o clinical events following liver transplantation and be of prognostic significance following renal transplantation. The aim of this study w as to examine T lymphocyte subsets, their activation status and the me an fluorescence intensity of cell surface markers by now cytometric an alysis, in peripheral blood of patients following liver transplantatio n. Stable transplant patients (n=11) had a significantly higher level of activation (HLA-DR expression) of all T cell subsets: CD3, CD4 and CD8 compared to healthy controls : 17.5% +/- 14.0 (mean +/- SD) vs 4.7 +/- 1.8 (p=0.04), 13.7% +/- 10.3 vs 4.3 +/- 1.7 (p=0.03) and 23.8% +/ - 19.9 vs 3.6 +/- 2.4 (p=0.02) respectively. A further increase in act ivation status occurred in all T cell subsets in association with acut e cellular rejection, reaching significance for the CD4+ population: 1 3.7% +/- 10.2 vs 23.3% +/- 20.6 (p=0.04). The mean fluorescence intens ity of the CD3+DR- and CD3+ DR+ populations were increased to 1397 +/- 869 and 1282 +/- 810 following liver transplantation compared to valu es of 425 +/- 204 and 376 +/- 166 respectively for controls (p<0.05). T-lymphocytes maintain a high level of activation following liver tran splantation and continue to express high levels of the surface marker CD3, which may account for the occurrence of acute cellular rejection despite immunosuppression in these patients.