Regulatory effect of FK506 on CD152 and PD-1 in the liver allorecipients

AIM: We dynamically observed the expression of CD152 and PD-1 on T-cell surfaces in peripheral blood of liver allorecipients to explore the regulatory effect of FK506 on negative costimulatory molecules. METHODS: We evaluated 20 liver allorecipients, 19 end-stage liver disease patients, and 20 healthy volunteers for FK506 concentrations measured by an enzyme-multiplied immunoassay technique and flow cytometry to determine T-cell subsets as well as CD152 and PD-1 expression. RESULTS: After liver transplantation, the frequency of CD4+ T cells gradually decreased to significantly lower level than those in the disease controls (P < .05). CD8+ T cells in each treatment group were obviously higher than those in the disease controls (P < .05). The expression of CD152 on CD4+ and CD8+ T cells was greater than those in healthy controls (P < .05); and at 2 and 4 weeks, higher than those in disease controls (P < .05). The expression of PD-1 on CD4+ T cells from the 2 weeks after treatment was significantly greater than that in healthy controls (P < .05), and that on CD8+ T cells increased obviously from the 4 weeks compared with disease controls (P < .05). CONCLUSION: FK506 up-regulated the expression of CD152 and PD-1 on the T-cell surface inhibiting proliferation and activation of effector T cells, favoring the survival of allorecipients.