Abstract:
Objective To investigate the relationship between the metabolic rate of tacrolimus (FK506) and BK virus infection early after renal transplantation.
Methods Eighty recipients undergoing allogenic renal transplantation in Institute of Organ Transplantation of the 309th Hospital of Chinese People' s Liberation Army were recruited in this study. The polymorphism of cytochrome P450 (CYP) 3A5 gene was detected in 80 recipients. All patients were divided into fast metabolism group (CYP3A5*1/*3 and CYP3A5*1/*1 genotypes, n=38) and slow metabolism group (CYP3A5*3/*3 genotype, n=42) based on the gene detection results. The distribution of CYP3A5 genotypes in 80 recipients was analyzed. The metabolic rate concentration/dose ratio (C/D value) of FK506 was statistically compared between two groups. The incidence of BK virus infection events BK viruria, BK viremia and BK virus nephropathy(BKVN) within postoperative 6 months were compared between two groups.
Results Among 80 recipients, 5 cases (6%) were detected with CYP3A5*1/*1 genotype, 33 (41%) with CYP3A5*1/*3 genotype, and 42 (53%) with CYP3A5*3/*3 genotype. Among the 160 alleles in 80 recipients, 117 CYP3A5*3 allele were identified, suggesting that the mutation rate of CYP3A5*3 allele was 73.1%. In the fast metabolism group, the C/D values at postoperative 1, 3, and 6 months were significantly lower than those in the slow metabolism group (all P < 0.01). The incidence rates of BK viruria in the fast and slow metabolism groups were 37% and 29%, 18% and 2% for BK viremia, and 3% and 0 for BKVN, respectively. In the fast metabolism group, the incidence of BK virenia was significantly higher than that in the slow metabolism group (P=0.02). The incidence of BK viruria and BKVN did not significantly differ between two groups (both P > 0.05).
Conclusions According to the CYP3A5 genotyping outcomes, the recipients with a high metabolic rate of FK506 have a high risk of BK viremia early after renal transplantation.