Toll-like receptor changes and its clinical significance in peripheral blood mononuclear cells in neonates and infants under surgical stress

Objective To examine Toll-like receptor 2(TLR2) and Toll-like receptor 4(TLR4) expression in monocytes in neonates and infants under surgical stress and to study its clinical significance.Methods A total 32 patients were divided into neonate group(n = 9) and infant group(n = 23).Samples of 2 ml peripheral blood were obtained and heparinized before operation,at the end of operation,and 1,3,7 days after operation.(1) TLR2 and TLR4 expressions on peripheral blood mononuclear cells(PBMCs) were analyzed by flow cytometry.(2) PBMCs were isolated and stimulated with LPS.Concentrations of IL-6 and TNFα in the PBMC culture supernatants were measured with enzyme-linked immunosorbent assay.Results(1) TLR2 and TLR4 expressions in the neonate group significantly decreased at the end of the operation(P 0.05),and then returned to preoperative level on postoperative day 1(P 0.05).TLR2 and TLR4 expressions significantly decreased in the infant group at the end of the operation(P 0.05),and then returned to preoperative levels on postoperative day 1(P 0.05).(2) TNFα was significantly suppressed at the end of the operation after stimulated with LPS and showed gradual increment on postoperative day 1 and IL-6 showed no significant change.Conclusions Early-stage surgical insults can down-regulate TLR2 and TLR4 expressions on peripheral blood mononuclear cells,thus suppressing immune responses to microbial pathogens.