Endothelial nitric oxide synthase polymorphism influences renal allograft outcome

Atherosclerotic lesions within the graft are considered to be a major cause of interstitial fibrosis/tubular atrophy (IF/TA). We evaluated the factors that influence the development of IF/TA and three- and five-yr graft survival including nitric oxide synthase (eNOS) and angiotensin II type 1 and type 2 receptor gene polymorphism.

Seventy-one male and 35 female patients (age: 34.9 ± 11.2 yr) who underwent living-related renal transplantation were included. Angiotensin type 1 and type 2 receptor gene polymorphisms and eNOS intron 4 gene polymorphism were analyzed. The pre- and post-transplant laboratory data, patient characteristics, acute rejection episodes, and presence of IF/TA were evaluated.

Patients with the bb allele of eNOS gene had a lower prevalence of post-transplant third year (12.6% and 38.5%, p = 0.005) and fifth year IF/TA (46.6% and 82.3%, p = 0.02) and a lower incidence of five-yr graft failure (35.4% and 55.6%, p < 0.005). The eNOS gene polymorphism was independent and was the most prominent factor associated with third and fifth year IF/TA (p = 0.01, RR: 29.72, and p = 0.03, RR: 4.1, respectively). No significant relationship existed when angiotensin II gene polymorphisms were considered.

We concluded that recipient eNOS gene polymorphism can predict IF/TA, and the presence of the bb allele is associated with better graft outcome.