Characterisation of Interleukin-8 and monocyte chemoattractant protein-1 expression within the abdominal aortic aneurysm and their association with mural inflammation.
OBJECTIVE
Abdominal aortic aneurysms (AAAs) are characterised by chronic transmural inflammation. This study investigated the expression of interleukin-8 (IL-8) and monocyte chemoattractant protein-1 (MCP-1) within the AAA, and their relationship with mural inflammation.


METHODS
Biopsies were obtained from 25 AAAs, 15 abdominal aortas, and 10 atherosclerotic thoracic aortas. IL-8 and MCP-1 expression was measured in homogenised specimens by ELISA. Infiltrate composition and localised expression of IL-8 and MCP-1 were determined through immunohistochemistry.


RESULTS
ELISA analysis demonstrated that IL-8 and MCP-1 were raised in the AAA compared to the controls [(IL-8, AAA vs. abdominal aorta: >28-fold, P<.001; AAA vs. thoracic aorta: >28-fold, P<.001) (MCP-1, AAA vs. abdominal aorta: 9-fold, P<.001; AAA vs. thoracic aorta: 19-fold, P<.001)]. Immunohistochemistry revealed that IL-8 was localised to the inflammatory infiltrate, which consisted predominantly of CD3(+) T- and CD20(+) B-lymphocytes. MCP-1 was predominantly expressed by CD68(+) macrophages. Increasing IL-8 expression was associated with an increase in mural inflammation, and an increase in CD3(+) T-lymphocytes of CD4(+) phenotype within the infiltrate population.


CONCLUSIONS
Pathways involving IL-8 and MCP-1 may be involved in AAA pathogenesis. IL-8 may be directly involved in the chemotaxis of T(H)-lymphocytes into the AAA wall.
Middleton
R K
RK
Department of Cardiovascular Sciences, Vascular Surgery Group, University of Leicester, Leicester, UK. rk_middleton@yahoo.co.uk
Bown
M J
MJ
Lloyd
G M
GM
Jones
J L
JL
London
N J
NJ
Sayers
R D
RD
D000328:Adult; D000368:Aged; D017544:Aortic Aneurysm, Abdominal / Q000276:immunology* / Q000473:pathology; D018932:Chemokine CCL2 / Q000096:biosynthesis* / Q000276:immunology; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D016209:Interleukin-8 / Q000096:biosynthesis* / Q000276:immunology; D008214:Lymphocytes / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D055815:Young Adult
C111835:CCL2 protein, human; D018932:Chemokine CCL2; D016209:Interleukin-8