Impacts of concentrations of Tacrolimus on NK cells and receptors in peripheral blood of renal transplant recipients / 中华器官移植杂志

ABSTRACT

Objective To study the effects of tacrolimus(Tac) concentrations on the number of NK cells and receptor expression in peripheral blood of renal transplantation receptors.Methods A total of 60 first-time kidney transplantation recipients in our institute from Dec.2007 to July 2009 were followed up.Tac maintenance immunosuppressive therapy was given to all recipients.The recipients were divided into low-concentration Tac group (6.84 + 1.72μg/L,n =30) and highconcentration Tac group ( 11.88 + 2.59 μg/L,n =30) according to concentrations of Tac.Twenty healthy volunteers served as controls.Before and 6 months after operation,concentrations of Tac were analyzed by using micro particle immunoassay chemiluminescent method.NK cells and their receptors (CD85j,CD158d,CD94 and NKG2D) were detected by using flow cytometry.The concentrations of soluble HLA-G5 were detected by using ELISA.Results The number of NK cells in lowconcentration Tac group and high-concentration of Tac group preoperatively was significantly reduced as compared with control group (P ＜ 0.05 ). The percentage and number of NK cells in low concentration Tac group and high-concentration Tac group at 6th month after operation were significantly reduced as compared with control group (P＜0.05).The number of NK cells in lowconcentration Tac group was significantly greater than in high-concentration Tac group (P＜ 0.05).There was no significant differende in the expression of CD85j,CD158,CD94 and NKG2D before operation between two groups(P＞0.05).The expression of CD85j and CD158d in two groups was increased,but that of CD94 and NKG2D was decreased at 6th month post-transplantation as comapred with that preoperation.In low-concentration Tac group,the expression of CD85j and CD158d was increased as compared with that in high-concentration Tac group (P＜0.05 ).Spearman correlation analysis revealed that the CD85j and CD158d expression had a positive correlation with sHLA-G5(P＜0.01 ),but the NKG2D had a negative correlation with sHLA-G5(P＜0.01 ).Conclusion There was correlation between the concentrations of Tac and NK cells count and NK receptors. Low concentrations of Tac can safely and effectively protect kidney function.The number of NK cells andtheir inhibitor receptors are increased in the recipients with low concentration of Tac.