Impact of CYP3A5 and MDR-1 gene polymorphisms on the dose and level of tacrolimus among living-donor liver transplanted patients: single center experience

AIM OF WORK: To assess the impact of Cytochrome P450 3A5 (CYP3A5) and multidrug resistance-1 gene (MDR-1) single nucleotide polymorphisms on the dose and blood level of tacrolimus among liver transplanted patients. PATIENTS AND METHODS: We enrolled a prospective study of 41 liver transplanted patients. Dose-adjusted trough blood concentration (C/D ratio) was calculated. Polymerase chain reaction-restriction fragment length polymorphism followed by sequencing was done for genotyping of CYP3A5*3 (6986A > G). RESULTS: At 1 week, 1 and 3 months C/D ratio were significantly lower in CYP3A5 expressers *1/*1 patients compared to non-expressers *3/*3. CONCLUSION: CYP3A5 (6986A > G) genotype, rather than MDR-1 (2677G > A/T) variant, has an impact on tacrolimus pharmacokinetics.