Effect of pregnane X receptor polymorphisms on tacrolimus blood concentrations and the resulting adverse reactions in kidney transplantation recipients

We investigated the effect of pregnane X receptor (PXR) polymorphisms on tacrolimus (FK506) blood trough concentrations and the associated adverse reactions in kidney transplantation recipients (KTRs). Polymerase chain reaction (PCR)-restriction fragment length polymorphism was used to detect the genotypes of single nucleotide polymorphism loci in 336 KTRs. The PXR six-base deletion mutation was classified using specific allele PCR, and the FK506 blood trough concentration in the KTRs was measured by chemiluminescent microparticle immunoassay. There were significant differences in adverse reactions resulting from FK506 in age, weight, body mass index (BMI) and treatment course (P < 0.05). Logistical regression revealed that the FK506 treatment course and BMI were risk factors for hyperlipidemia, and the risk of hyperlipidemia increased 27.534 times when the BMI was less than 18.5. Moreover, age was also a risk factor leading to hyperglycemia. FK506 blood trough concentration and C-0/D value had an impact on adverse reactions induced by hyperglycemia. The KTRs' PXR rs3842689, rs6785049, and rs1523127 mutation frequencies were 26.07, 11.79, and 16.07%, respectively. There was no statistically significant difference in the mutation frequency of each locus between the control group and the adverse reaction groups. Therefore, rs3842689, 7635G> A (rs6785049), and 24381C> A (rs1523127) PXR polymorphisms have no obvious impact on FK506; furthermore, the PXR rs3842689 wild-type homozygous WW genotype is a risk factor of FK506 and results in gastrointestinal reactions.