CD16+ monocytes have recently shown the ability to inhibit the proliferation of CD4+CD25+Foxp3+ T cells (Tregs). The inhibitory role of Tregs in acute rejection has been described in patients with liver transplantation. However, the role of CD16+ monocytes in the development of allograft rejection after liver transplantation remains unknown.Methods.
Forty-five liver transplant recipients, including 25 acute rejection diagnosed by liver biopsy and clinical symptoms and 20 stable allograft liver function recipients, were collected from January 2007 to September 2015 at our hospitals. To assay the frequencies of CD16+ monocytes and Tregs in blood samples, flow cytometry was performed.Results.
Compared with the stable allograft liver function recipients, a significant increase in CD16+ monocytes (19.45±5.25% vs 7.17±1.69%, P<0.001) and decreased Tregs (1.74±0.59% vs 5.53±2.18%, P<0.001) was observed among recipients with acute rejection. CD16+ monocytes were positively correlated with RAI (rejection activity index) (R2=0.84, P<0.001), but negatively correlated with the frequency of Tregs (R2=0.86, P<0.001).Conclusions.
Based on our data, we concluded that CD16+ monocytes might be responsible for the development of acute allograft rejection after liver transplantation, which may be associated with inhibition of Treg cells.