The impact of ICAM1 and VCAM1 gene polymorphisms on long-term renal transplant function and recipient outcomes

Intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) are implicated in endothelial cell-leukocyte adhesion. Several functional polymorphisms that affect the expression of ICAM-1 and VCAM-1, and therefore post-transplant immunological response, have been found in genes of these molecules. The aim of this study was to examine the impact of ICAM1 and VCAM1 gene polymorphisms on long-term renal transplant function and recipient outcome during a 5-year follow-up period.

The study enrolled 269 Caucasian renal transplant recipients (165 males, 104 females, mean age 47.58 ± 12.96 years) remaining under observation for 5 years. Genotyping of the c.1405A>G (Lys469Glu, rs5498) ICAM1, T(-1592)C (rs1041163), and T(-833)C (rs3170794) VCAM1 genes polymorphisms was performed using real-time PCR.

The rs5498 ICAM1 GG genotype was an independent risk factor associated with increased creatinine concentration at 12, 24, 36, 48, and 60 months after transplantation (p=0.0004, p=0.02, p=0.01, p=0.01 and p=0.04, respectively). Creatinine concentrations 36 and 48 months after transplantation were higher among CC homozygotes of the rs1041163 VCAM1 (TT+CT vs. CC, p=0.049 and p=0.04, respectively). The C allele of the rs1041163 VCAM1 gene polymorphism was identified as a risk factor for dialysis after transplantation (HR=3.323, 95%CI=1.44-7.67, p=0.005). The C allele of the rs1041163 VCAM1 gene was at the border of statistical significance as a risk factor for death after transplantation (p=0.06).

These results suggest that the rs5498 ICAM1 GG genotype is correlated with early and long-term allograft failure. The C allele of the rs1041163 VCAM1 gene may be associated with long-term allograft failure and graft loss, as well as increased morbidity after transplantation.