Pre- and Posttransplant IgA Anti-Fab Antibodies to Predict Long-term Kidney Graft Survival.

OBJECTIVES: Immunologic factors are reliable markers for allograft monitoring, because of their seminal role in rejection process. One of these factors is the immunoglobulin (Ig)A anti-Fab of the IgG antibody. This study aimed to evaluate the predictive value of pre- and posttransplant levels of this marker for kidney allograft function and survival. METHODS: Sera samples of 59 living unrelated donor kidney recipients were collected before and after transplantation (days 7, 14, and 30) and investigated for IgA anti-Fab of IgG antibody levels using enzyme-linked immunosorbent assay in relation with allograft outcome. RESULTS: Among 59 patients, 15 cases (25%) including 10 with acute rejection and 5 with chronic rejection episodes showed graft failure during a mean of 5 years of follow-up. High posttransplant levels of IgA anti-Fab antibodies were observed more frequently in patients with stable graft function (SGF) compared with patients with graft failure (P = 2 × 10(-6)). None of patients with acute or chronic rejection episodes had high levels of IgA anti-Fab antibodies at day 30 posttransplant compared with the SGF group (P = 10(-6) and P = .01, respectively). In addition, high levels of IgA anti-Fab antibody correlated with lesser concentration of serum creatinine at 1 month posttransplantation (P = .01). Five-year graft survival was associated with high levels of pre- and posttransplant IgA anti-Fab antibodies (P = .02 and P = .003, respectively). CONCLUSIONS: Our findings indicate the protective effect of higher levels of IgA anti-Fab antibodies regarding to kidney allograft outcomes and long-term graft survival.

Dynamic Changes of IFN-γ-producing Cells, TGF-ß and Their Preidctive Value in Early Outcomees of Renal Transplantation.

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.