TYPE: Abstract Publication TOPIC: Pulmonary Vascular Disease PURPOSE: The aim of our study was to define some mediators of ED and angiogenesis (endothelin1 (ET-1), vascular endothelial growth factor (VEGF), Plasminogen Activator Inhibitor-1 (PAI1) in patients with different clinical forms of IIP. METHODS: PATIENTS AND METHODS: 39 patients (22 – usual interstitial pneumonia, 17 – nonspecific interstitial pneumonia) with morphologically proved IIP were examined. Standard clinical examination, pulmonary function tests, echocardiography, high-resolution computed tomography (HRCT), measurement of diffusion capacity of the lung for carbon monoxide (DLCO) were evaluated. Plasma concentrations of ET-1, VEGF and PAI1 (ELISA) and morphometrics of lung biopsy for estimation of intensity of neoangiogenesis were performed. RESULTS: RESULTS: Markers of ED correlated positively with HRCT patterns of lung fibrosis (VEGF r=0,31, p=0,004; ET-1 r=0,37 p=0,003, PAI-1 r=0,38, р=0,006), the level of VEGF in the blood correlated with parameters of neoangiogenesis in the lung tissue (r=0,37, p=0,001). Patients with PH in comparison with patients without PH demonstrated higher concentrations of ЕТ-1 и PAI-1 (r=0,34, p=0,005 and r=0,37, р=0,002 respectively). Inverse correlation was established between PAI-1 and DLCO (r = -0,71, p<0,05), PAI-1 and FVC (r = -0,72, p<0,05). CONCLUSIONS: CONCLUSION: these data demonstrate the important role of the studied markers of ED and neoangiogenesis in the mechanisms of IIP progression and may be used as predictors of survival. CLINICAL IMPLICATIONS: Angiogenesis and endothelial dysfunction(ED) in idiopathic interstitial pneumonias(IIP) are considered as key mechanisms of lung tissue remodeling and pulmonary hypertension (PH). DISCLOSURE: No significant relationships. KEYWORDS: endothelial dysfunction, interstitial pneumonias