CHRONIC INFLAMMATION AND ELASTIN DEGRADATION IN ABDOMINAL AORTIC-ANEURYSM DISEASE - AN IMMUNOHISTOCHEMICAL AND ELECTRON-MICROSCOPIC STUDY

Objectives: To investigate (i) elastin degradation and the possible as sociation between proteolysis and inflammation in abdominal aortic ane urysm disease (AAA), and (ii) the presence of cytomegalovirus (CMV) in fection in the walls of AAA. Materials: Specimens from 12 infrarenal A AAs, eight aortas with occlusive disease (AOD) and two normal aortas w ere studied by conventional light microscopy, immunohistochemistry usi ng a monoclonal anti-elastin antibody BA-4 and anti-CMV antibody and t ransmission electron microscopy (TEM). Main results: In AAA the decrea se in elastin immunoreactivity and the presence of elastin degradation was associated with increased mononuclear, inflammatory cell infiltra tes (p=0.004 and p=0.00002, respectively). The CMV immunostainings of the normal aortic wall and all the AAA and AOD samples were negative, nor could any CMV particles be demonstrated by TEM. Conclusions: The c hronic inflammation and degradation of elastin in AAA suggests a possi ble immune-mediated mechanism. The inflammation may be induced by the chemotactic properties of elastin-derived peptides.