ABSTRACT
BACKGROUND: A growing body of evidence demonstrated an immune etiology as well as nonimmune mechanisms for episodes of clinical acute rejection and long-term allograft dysfunction. OBJECTIVE: To investigate the correlation of IFN-γ-producing cells and TGF-ß with incidence of clinical acute rejection in living-related and unrelated kidney allogarft recipients during the first post-transplant year. METHODS: This multi-center study was performed on 57 kidney allograft recipients from living-related (n=20) and unrelated (n=37) donors between April 2011 and September 2012 and who were followed prospectively for a mean period of one year. Peripheral blood samples were collected from all patients pre-transplantation and at days 14, 30 and 90 after transplantation; PBMCs were used as responding cells in enzyme-linked immunosorbent spot (ELISPOT) assay to measure the frequency of IFN-γ-producing cells after stimulation with donor lymphocytes. Additionally, TGF-ß levels were measured in cell culture supernatants of ELISPOT assay. RESULTS: During the follow-up period, 45 (79%) patients were diagnosed with stable graft function (group A); 12 (21%) experienced clinical acute rejection episodes (group B). The frequency of IFN-γ-producing cells was significantly (p<0.001) higher in the rejection group in all three times after transplantation. Also, post-transplantation comparison for TGF-ß showed a significantly (p<0.001) higher contents in group A vs. group B. Comparing the post-transplantation levels of TGF-ß and mean numbers of IFN-γ- producing cells between groups A and B demonstrated a continuous increment in TGF-ß and decreasing frequencies of IFN-γ-producing cells in group A vs. group B. CONCLUSION: Serial post-transplantation monitoring of IFN-γ-producing donor reactive cells during the first months is a clinically feasible approach for identification of kidney allogarft recipients at risk for ongoing immune-mediated graft damage and later graft loss.
ABSTRACT
The pretransplant cytokine profile of donor and recipient blood and tissues may be associated with transplant outcome. A Th1 response is generally associated with transplant rejection, while a Th2 response may lead to tolerance and stable graft survival. A total of 56 (37 male and 19 female) patients of mean 36 +/- 5 years were candidates for living unrelated kidney transplantation. Serum samples were collected 24 hours pretransplantation as well as at 1 and 2 weeks posttransplantation. Immunosuppression consisted of cyclosporine, prednisolone, and mycophenolate mofetil. Among the transplanted patients, 19 (33.9%) individuals experienced an acute rejection episode, as proven by biopsy, as well as an increased serum creatinine and blood urea nitrogen, within 14 days after transplantation. We determined serum concentrations of interleukin (IL) 2 and interferon (IFN)-gamma for Th1 and IL4 and IL10 for Th2 by an enzyme-linked immunosorbent assay method (Bender med system kits, Germany). Among Th1 cytokines, the mean concentration levels for groups with versus without acute rejection were: IL-2 pretransplant 15 pg/mL vs 6.8 pg/mL, respectively (P = .005); IL-2 at 1 week, 19 pg/mL vs 4.85 pg/mL, respectively (P = .001); IL-2 at 2 weeks, 21.1 pg/mL vs 4.65 pg/mL, respectively (P = .0001); IFN-gamma pretransplant 161.1 pg/mL vs 65.2 pg/mL, respectively (P = .001); IFN-gamma at 1 week, 175.6 pg/mL vs 66.5 pg/mL, respectively (P = .001); and IFN-gamma at 2 weeks, 173.7 pg/mL vs 77.1 pg/mL (P = .001). IL-2 and IFN-gamma levels were significantly higher in the group with acute rejection versus those without acute rejection. In conclusion, these data suggest that cytokine analysis, especially of Th1 cytokines, might be a valuable prognotic index of kidney transplant outcome.
