Effect of CYP3A5*1 expression on tacrolimus required dose after liver transplantation: A systematic review and meta-analysis.

We systematically collected eligible data to measure the effect of CYP3A51 expression on personalized tacrolimus therapy. Six databases were searched for studies on adult liver transplant recipients and donors of liver graft which reported tacrolimus dose requirement, trough blood concentration, and/or concentration/dose (C/D) ratio in expressers and nonexpressers of CYP3A51. Eligible data were pooled by meta-analysis. Sixteen observational studies (1309 recipients, 1044 donors of liver graft) were included in the analyses. Tacrolimus C/D ratio was lower, and the dose was higher in recipient expressers of CYP3A51 and/or carriers of expresser liver graft at 1-4 weeks and 2-4, 6, and 12 months post-transplantation. Tacrolimus blood concentration was lower at the first two weeks. Pair expressers were affected by about twofold, and the effect was different between ethnic groups. CYP3A51 expression in recipients increased tacrolimus required dose by 0.023 at first, 0.022 at third, and 0.012 mg/kg/day at sixth month. Its expression in graft tissue increased tacrolimus required dose by 0.024 at first, 0.035 at third, and 0.032 mg/kg/day at sixth month. Considering CYP3A5*1 polymorphism can be helpful in individualization of tacrolimus efficient dose prior to administration, and it can remove initial high-risk lag time (over/underdose period before reaching target blood level) at first few days post-transplantation.