Abstract:

Ｏｂｊｅｃｔｉｖｅ：To investigate the effect of CYP3A4*18B, CYP3A5*3 and MDR1 on concentration/dosage×body body weight ratios (C/D) of tacrolimus in renal transplant patients.
Ｍｅｔｈｏｄｏｌｏｇｙ：The CYP3A4*18B, CYP3A5*3, MDR1 C1236T, G2677T/A and C3435T genotypes of 227 renal transplant patients were determined by PCRRFLP method. The differences of C/D ratios were compared among all of the genotype groups treated with tacrolimus.
Ｒｅｓｕｌｔｓ：CYP3A4*18B and CYP3A 5*3 gene polymorphisms were associated with the C/D ratios of patients (P<001). No significant association was found between C/D of tacrolimus and CYP3A4*18B genotypes when they were classified by two CYP3A5 genotypes (P>005), While after the effects of CYP3A4*18B genotype was eliminated, the C/D ratio of tacrolimus in patients with CYP3A5*1/*1 and *1/*3 genotype group were significantly lower than those with CYP3A5*3/*3 genotype groups (P<001). There was no significant difference in the C/D ratio of tacrolimus among  MDR1 C1236T，MDR1 G2677T/A and MDR1 C3435T genotype groups．
Ｃｏｎｃｌｕｓｉｏｎ：CYP3A4*18B and MDR 1 gene polymorphisms do not affect blood  concentration of tacrolimus.

Key words: renal transplantation, tacrolimus, polymorphism, Blood drug concentration