Angiogenic activity of sera from interstitial lung disease patients in relation to angiotensin-converting enzyme activity.

The role of angiogenesis in the pathogenesis of interstitial lung diseases (ILD) is unknown. Angiotensin-converting enzyme (ACE) is a marker of sarcoidosis activity and may modulate angiogenesis. The aim of this study was to examine the relationship between ACE activity in ILD patients' sera and their effect on microvessels formation in an in vivo model of leukocyte-induced angiogenesis. The study population consisted of 77 sarcoidosis patients, 22 idiopathic pulmonary fibrosis patients, 16 bird fanciers lung patients, eight silicosis patients and 14 healthy donors. Serum ACE activity was assayed by spectrophotometric method. As an angiogenic test, a leukocyte-induced angiogenesis assay in an animal model was used. Sera from interstitial lung disease patients significantly stimulated angiogenic activity of mononuclear cells compared with healthy donors (p < 0.001). The highest ACE serum activity was measured in sera from the silicosis patients, and lowest in sera from the sarcoidosis and IPF patients. A significantly lower serum ACE activity was detected in the bird fanciers lung patients. Serum angiogenic activity of ILD patients measured by angiogenesis index negatively correlated with ACE serum activity (r = ;-0.52; p < 0.01). This correlation was highest in the sarcoidosis group (r = -0.6; p < ). Sera from ILD patient constitute the source of factors modulating angiogenesis.