Chronic inflammation and elastin degradation in abdominal aortic aneurysm disease: an immunohistochemical and electron microscopic study.
OBJECTIVE
To investigate (i) elastin degradation and the possible association between proteolysis and inflammation in abdominal aortic aneurysm disease (AAA), and (ii) the presence of cytomegalovirus (CMV) infection in the walls of AAA.


METHODS
Specimens from 12 infrarenal AAAs, eight aortas with occlusive disease (AOD) and two normal aortas were studied by conventional light microscopy, immunohistochemistry using a monoclonal anti-elastin antibody BA-4 and anti-CMV antibody and transmission electron microscopy (TEM).


RESULTS
In AAA the decrease in elastin immunoreactivity and the presence of elastin degradation was associated with increased mononuclear inflammatory cell infiltrates (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 chronic inflammation and degradation of elastin in AAA suggests a possible immune-mediated mechanism. The inflammation may be induced by the chemotactic properties of elastin-derived peptides.
Satta
J
J
Department of Surgery, University of Oulu, Finland.
Laurila
A
A
Pääkkö
P
P
Haukipuro
K
K
Sormunen
R
R
Parkkila
S
S
Juvonen
T
T
D000328:Adult; D000368:Aged; D000956:Antigens, Viral / Q000032:analysis; D017544:Aortic Aneurysm, Abdominal / Q000473:pathology*; D001402:B-Lymphocytes / Q000473:pathology; D002908:Chronic Disease; D003586:Cytomegalovirus Infections / Q000473:pathology; D004549:Elastin / Q000648:ultrastructure*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D016130:Immunophenotyping; D007249:Inflammation / Q000473:pathology; D008264:Macrophages / Q000473:pathology; D008297:Male; D008854:Microscopy, Electron; D008875:Middle Aged; D013601:T-Lymphocytes / Q000473:pathology
D000956:Antigens, Viral; D004549:Elastin