Correlation of CD95 and soluble CD95 expression with acute rejection status of liver transplantation

To analyze the expression levels of soluble form of CD95, CD95 ligand (sCD95 and sCD95L, respectively) in plasma and CD95 expression on CD3+ cells in liver-transplanted recipients with acute rejection (AR).

Peripheral blood mononuclear cells (PBMCs) were isolated from 30 clinically liver transplanted recipients. CD95 expression on CD3+ cells was quantitatively measured by two-color fluorescence activated cell sorter (FACS) analysis. Lymphocyte surface phenotypes of CD4, CD8, CD16 and CD56 were determined by flow cytometry. Plasma levels of sCD95 and sCD95L were detected by Enzyme Linked-Immuno-Sorbent Assay (ELISA). The results were compared with that from normal healthy volunteers (n = 15 individuals).

FACS analysis showed that CD95 expression on CD3+ T cells was significantly increased in liver transplanted recipients with AR compared to that in stable recipients without rejection and infection or healthy individuals who did not undergo transplantation (18,676.93+/-11,588.34/molecule, 6,848.20+/-1 712.96/molecule, 6,418.01+/-2,001.95/molecule, respectively, P<0.01). Whereas no significant difference was seen between liver-transplanted stable recipients and healthy individuals. Furthermore, no significant differences were detected between each group with CD4/CD8 ratio or the percentage of CD16+56+ cells. Plasma levels of sCD95 were significantly higher in transplanted recipients with AR compared to that in stable recipients or healthy individuals (391.88+/-196.00, 201.37+/-30.30, 148.83+/-58.25 pg/mL, respectively, P<0.01). In contrast, the plasma levels of sCD95L in liver- transplanted recipients were not significantly different from that in healthy individuals.

The present results indicate that the increased CD95 expression on CD3+ cells and the increased levels of sCD95 in plasma may modify the immunological situation of the recipients after transplantation or represent the ongoing graft rejection.