Selective intra-graft apoptosis and down-regulation of lymphocyte bcl-2, iNOs and CD95L expression in kidney-pancreas transplanted patients after anti-Thymoglobulin induction

Intra-graft infiltrating cells apoptosis was evaluated in 20 consecutive kidney-pancreas transplanted (KP) patients without kidney rejection. Two fine-needle aspirated biopsy (FNAB) and two peripheral blood lymphocytes (PBL) samples were obtained 14 days after transplantation. Immunosuppression was based on anti-Thymoglobulins (ATG) induction for 7 days and cyclosporine/mofetil mycophenolate as maintenance therapy. Ten matched healthy subjects were chosen as controls for PBL. Lymphocyte phenotypes and activation markers, apoptotic rate and lymphocyte expression of pro/anti-apoptotic molecules were analysed by flow cytometry analysis (FACS). Lymphocyte phenotypes and activation markers: higher levels of CD8 and CD4DR were evident in the graft (p < 0.05) than in PBL, CD3CD25 in PBL were higher in transplanted patients than in controls. Apoptotic rate and lymphocyte expression of pro- and anti-apoptotic molecules: a higher expression of annexin V, together with reduced lymphocytes CD95L, iNOs and Bcl-2 expression (PBL = 97.7+/-1.1% vs FNAB = 81.9+/-15.1%; p < 0.05) were evident in the graft than in PBL. In KP patients intra-graft apoptosis and reduced anti-apoptotic molecules were evident after ATG induction.