Immunohistochemical study of intimal microvessels in coronary atherosclerosis.

Two hundred ninety-nine human coronary artery paraffin-embedded tissue blocks were examined for intimal microvessel invasion by probing for factor VIII-associated antigen with indirect immunofluorescence and high resolution confocal microscopy. The results obtained confirm that intimal microvessels originate in the adventitia and show that the richness of intimal microvessels is strongly positively correlated with intimal thickness and negatively correlated with relative lumen size. A number of plasma constituents were examined in serial sections. Comparison of immunofluorescence distribution patterns of these components with intimal microvessel distribution patterns reveals that intimal microvessels leak plasma albumin into artery walls, exude fibrinogen, and are associated with the build-up of plasma cells within atherosclerotic lesions. Therefore, intimal microvessels are demonstrated to play important roles in the development of atherosclerosis.