Angiogenic activity of sera from interstitial lung disease patients in relation to clinical and radiological changes

Clinical symptoms and radiological changes are useful in monitoring patients with interstitial lung diseases (ILD). Neovascularization participates in the pathogenesis of idiopathic pulmonary fibrosis and other ILD. The objective of the study was to examine the relationships between angiogenic activity of sera from ILD patients and clinical or radiological status.

Serum samples were obtained from 83 patients with sarcoidosis, 31 with idiopathic pulmonary fibrosis (IPF), 29 with hypersensitivity pneumonitis (HP), 16 with collagen diseases with pulmonary manifestation (CD), 13 with scleroderma (SCL), 14 with Wegener's granulomatosis (WG), 12 with pulmonary Langerhans cell histiocytosis (HIS), 12 with pneumoconiosis (PNC), 10 with drug-induced lung disease (DLD), 5 with cryptogenic organizing pneumonia (COP), and from 36 healthy volunteers. As an angiogenic test we used a cutaneous angiogenesis assay according to Sidky and Auerbach. Clinical status was evaluated using a special questionnaire. In all patients chest radiographs were performed.

The angiogenic properties of sera from ILD differed depending on the clinical diagnosis. The strongest proangiogenic effect was induced by sera from patients with HP (mean number of new vessels 16.8), CD (16.6), sarcoidosis (16.3), IPF (16.2), and PNC (15.7). In the case of DLD (13.2), the effect was comparable to healthy controls (13.5). In contrast, sera from SCL (mean number of the vessels 10.5) and HIS patients (10.8) significantly inhibited angiogenesis compared with controls. The angiogenic activity of sera from patients with hilar or mediastinal lymph nodes involvement was higher than that of sera from patients with lung fibrosis. There were also differences in the serum angiogenic activity in relation to the severity of dyspnea.

The data showed that sera from ILD patients constitute a source of mediators modulating angiogenesis, but the pattern of reaction is different in various diseases. Sera from HP, sarcoidosis, IPF, and CD patients demonstrated the strongest proangiogenic activity. However, sera from SCL and HIS inhibit angiogenesis. Angiogenic activity of examined sera was related to the clinical and radiological changes.