High prevalence of polymorphisms of angiotensin-converting enzyme (I/D) and endothelial nitric oxide synthase (Glu298Asp) in patients with systemic sclerosis

Purpose Systemic sclerosis is characterized by progressive microvascular occlusion and fibrosis and by an imbalance in the fibrinolytic system. In vivo and in vitro studies suggest that the renin-angiotensin system partly regulates vascular fibrinolytic balance. Angiotensin II increases the production and secretion of plasminogen activator inhibitor-1, while angiotensin-converting enzyme (ACE) contributes to reduced production of tissue plasminogen activator and endothelial nitric oxide synthesis by bradykinin degradation. The aim of our study was to investigate the effects of ACE insertion/deletion (I/D) and endothelial nitric oxide synthase (eNOS) Glu298Asp (G894→T) and T–786→C polymorphisms in patients with systemic sclerosis. Subjects and methods We studied 73 consecutive patients (47 with limited and 26 with diffuse cutaneous systemic sclerosis) and 112 control subjects. ACE I/D and eNOS polymorphisms were genotyped by polymerase chain reaction–restriction fragment length polymorphism analysis. Results The ACE I/D and the eNOS G894→T polymorphisms were more common in patients than in controls (for the ACE D allele: odds ratio [OR] = 3.4; 95% confidence interval [CI]: 1.5 to 7.9; P = 0.003; for the eNOS T allele: OR = 1.9; 95% CI: 1.0 to 3.4; P = 0.04). There was no association between the eNOS T–786→C polymorphism and systemic sclerosis. Conclusion Our findings of an increased risk of systemic sclerosis in ACE D and eNOS 894T allele carriers suggest that these polymorphisms may contribute to the pathogenesis of the disease.