ABSTRACT
Objective To establish an allele-specific PCR method for the detection of cytochrome P-450 CYP3A5 (A6986G) and multiding resistance gene MDR-1 (C3435T) polymorphisms,and investigate the correlations of their polymorphisms with blood tacrolimus (Tac) concentration/dose (C/D) ratio in renal transplant recipients.Methods The allele-specific PCR primers were designed according to the polymorphism sites of CYP3A5 (A6986G) and MDR-1 (C3435T) genes.Then,their polymorphisms in the genomic DNA of peripheral blood samples from 72 renal transplant recipients were analyzed,and the results were validated by DNA sequencing.The blood Tac concentration was determined by the chemiluminescence microparticle immunoassay and the differences of concentration,dose and C/D ratio of blood Tac in renal transplant recipients with different genotypes were compared at 1 month after transplantation.Results The coincidence rate between the established allele-specific PCR and DNA sequencing was 100％.The frequencies of CYP3A5 * 1/* 1,* 1/* 3 and * 3/* 3 genotypes in 72 renal transplant recipients were 18.1％,31.9％ and 50.0％,respectively,and those of MDR-1 C/C,C/T and T/T genotypes were 27.8％,58.3％ and 13.9％,respectively.There were significant differences in blood Tac concentration (P =0.014) and Tac C/D ratio (P =0.019) between different CYP3A5 genotypes of renal transplant recipients.Further analysis found that the Tac C/D ratio of CYP3A5 * 3/* 3 genotype was significantly higher than that of CYP3A5 * 1/* 1 and * 1/* 3 genotypes (P ＜ 0.05).Conclusion The allele-specific PCR method for the detection of CYP3A5 and MDR-1 polymorphisms is successfully established and the polymorphism of CYP3A5 * 3 gene in renal transplant recipients is obviously correlated with the pharmacokinetics of Tac.