Expression of circulating CD4+ CD25+ Foxp3+ regulatory T cells in liver allograft recipients with acute rejection

Abstract

Objective To investigate the expression of peripheral blood (PB) CD4+ CD25+ Foxp3+ regulatory T cells (Tregs) in patients with benign end-stage liver disease after liver transplantation and the relationship between levels of PB Tregs and acute rejection. Methods A prospective analysis was performed on 55 consecutive patients who underwent liver transplantation.Fourteen out of 55 cases suffered from acute rejection after liver transplantation were defined as rejection group,while the rest patients were classified into no acute rejection group. PB was obtained from liver transplant patients at different time points longitudinally: pre-transplant, post-transplant within one year and acute rejection. The circulating CD4+ CD25+ Foxp3+ Tregs in PB were measured by flow cytometry. Blood samples were drawn during acute rejection, at the same time, liver biopsies were performed. The circulating CD4+ CD25+ Foxp3+ Tregs were compared between two groups.Results There was no difference between two groups in levels of circulating CD4+ CD25+ Foxp3 + Tregs cells pre-transplant. However, the levels of circulating CD4+ CD25+ Foxp3+ Tregs in rejection group were decreased significantly as compared with no-rejection group (2. 23 % ± 0. 54 % vs. 2. 99 % ±0. 86 %,P＜0.01). The frequency of CD4+ CD25+ Foxp3+ T cells was negatively correlated with rejection activity index (RAI) (r = - 0. 80, P＜0. 01 ). Conclusion Monitoring PB CD4+ CD25+ Foxp3+ Tregs levels may be helpful in evaluating the immune state and act as a more sensitive marker for acute rejection diagnosis in the patients following liver transplantation. Key words: Liver transplantation; Rregulatory T-lymphocytes; Graft rejection