Immune Biomarkers in Renal Transplant Recipients and Long-Term Graft Outcome, a Retrospective Observational Cross-Sectional Indian Study - Abstract
Background: A major challenge for successful renal transplantation is to develop an efficient regulation to prevent allograft rejection. T helper 17 cells (Th17) (pro-inflammatory) and many regulatory T cells (CD4+CD25+; Tregs) (anti-inflammatory) have opposite functions influencing allograft survival. In contrast, IL-10, produced by multiple cells has potent anti-inflammatory properties. We have examined whether the evaluation of the percentage of Treg cells (Tregs %) in peripheral blood leukocytes (PBLs) as well as serum concentrations of IL-17 and IL-10 levels may correlate with allograft dysfunction and rejection.
Methods: This retrospective study included 57 patients who underwent kidney transplantation at the Nizam’s Institute of Medical Sciences (NIMS). All patients were followed up for a minimum of two years because of regular follow-up, allograft dysfunction, and/or allograft rejection. The Tregs% in PBLs and serum concentrations of IL 10 and IL-17 were measured simultaneously by the flow cytometry and sandwich Enzyme-linked immunosorbent assay (ELISA) method, respectively.
Summary: The level of Tregs% was significantly decreased in PBLs of patients during allograft rejection (GR) in comparison to patients with stable transplant (ST) (median 6.25% vs. 5.85%, p<0.05). Serum IL-17 concentrations increased significantly in patients with graft rejection than in those with ST. While serum IL-10 levels also increased in GR than that in ST but they were statistically not significant. Furthermore, the Treg% levels, as well as the ratios of Treg/IL-10, Treg/IL-17, and IL-17/IL-10, can predict the long-term graft outcome. Further epigenetic studies are required to understand the variability of IL-10 levels with variable graft function.