PAI-1 donor polymorphism influences long-term kidney graft survival

The type 1 plasminogen activator inhibitor (PAI-1) is involved in the development of fibrosis, and its intrarenal expression is increased in interstitial fibrosis and tubular atrophy (IFTA). Moreover, a 4G/5G polymorphism of the PAI-1 gene has been described associating 4G haplotype with higher PAI-1 plasma activity. We investigated the relationship between the donor and recipient PAI-1 polymorphism and kidney graft survival.

The PAI-1 genotype was determined for both the 304 donors and the 337 corresponding recipients. In recipients, PAI-1 antigen levels were also determined. We compared 4G/4G donors versus donors with other genotypes.

Donor or recipient genotype did not influence the PAI-1 plasma level in recipients. Actuarial kidney graft survival was significantly reduced in the 4G/4G donor group (107 months versus 147.5 months, P = 0.013), while recipient PAI-1 genotype did not show any influence on graft survival. Moreover, graft loss due to IFTA proved significantly higher in the 4G/4G donor group (13% versus 6%, P = 0.03). Multivariate analysis showed that the significant independent variables associated with graft loss were the donor 4G/4G genotype, acute clinical rejection and donor age.

Our study suggests that donor PAI-1 polymorphism influences kidney graft survival and that the donor 4G/4G genotype is an independent risk factor for graft loss. Prospective studies are needed to confirm these results.