FKBP1A rs6041749 polymorphism is associated with allograft function in renal transplant patients

To investigate the potential impact of single-nucleotide polymorphisms (SNPs) in the FK506-binding protein (FKBP)-calcineurin (CaN)-nuclear factor of activated T cells (NFAT) signaling pathway on the efficacy and safety of tacrolimus (TAC) in Chinese renal transplant patients.

Seventy-seven tag SNPs were detected in 146 patients who were on TAC-based maintenance immunosuppression and who followed up for at least 2 years. The relationships of these polymorphisms with clinical outcomes such as acute rejection, acute nephrotoxicity, pneumonia, and estimated glomerular filtration rate (eGFR) were explored. For the FKBP1A rs6041749 polymorphism, which has a significant association with renal function over time, a preliminary functional analysis was performed using a dual-luciferase reporter gene system.

The patients with FKBP1A rs6041749 TT genotype had a more stable eGFR level than CC and CT carriers (P = 2.08 × 10-8) during the 2 years following transplantation. Dual-luciferase reporter assay results showed that the rs6041749 C variant could enhance the relative luciferase activity compared with the T variant, which indicated that the rs6041749 C allele may increase the FKBP1A gene transcription. In addition, we did not find any association between these genetic variants and the risk of acute rejection, acute nephrotoxicity, and pneumonia in renal transplant patients receiving TAC-based immunosuppression.

FKBP1A rs6041749 C allele carriers are at higher risk for eGFR deterioration. The variant might serve as a biomarker to predict allograft function in renal transplant patients.