Increased eNOS levels in hereditary angioedema.

Abstract Background Hereditary angio-edema (HAE), characterized by recurrent episodes of angioedema involving the skin and the mucosa of the upper respiratory or the gastrointestinal tracts, results from heterozygosity for deficiency of the serine proteinase inhibitor (serpin), C1 inhibitor (C1-INH). Objective In this study, serum inflammatory cytokine levels and circulating endothelial cells collected from HAE patients during both acute attacks and asymptomatic periods were evaluated. Method Twenty-four patients with Type I and 1 patient with Type II HAE in an asymptomatic period (Group I), 8 patients with Type I HAE during a mild to moderate acute attack (Group II) and 20 healthy subjects (13 females, mean age: 32.1 ± 8.2 years) were included. Serum IL-6, IL-8, IL-1β, TNF-α, vascular endothelial growth factor (VEGF) and endothelial nitric oxide synthase (eNOS) levels were detected by ELISA. Circulating endothelial cells (CECs) and circulating endothelial progenitors (CEPs) were evaluated using Fluorescence Activated Cell Sorting (FACS). Results Serum eNOS levels of HAE patients were significantly higher than healthy subjects (p  Conclusion These results suggest that an inflammatory response is not necessary to trigger HAE attacks. On the other hand, increased eNOS levels might reflect a sustained hyperpermeability state in HAE patients.