Coronary Artery Progressive Stenosis Relates To Vascular Intimal Macrophage Infiltration And Plaque Formation

Macrophages play an important role in atherosclerotic plaqueformation, progression and rupture, which are responsible for the majorityof acute coronary syndromes. This study was to assess the relationshipbetween intimal macrophage infiltration and the progressive stenosis incoronary arteries. And at the same time we examined the relationshipbetween the MCP-1 and NF-κB expression and macrophage infiltration. Thirty-nine left anterior descending coronary arteries in 39 autopsiedcases were enrolled. The arteries were analyzed and divided into 3 groupsaccording to the degree of stenosis (group A: < 50% stenosis; group B:50% ~75% stenosis; group C: >75% stenosis). Inflammatory response wasgraded from G-0 to G-4 according to inflammatory cell infiltration inadventitia, media and intima. Immunohistochemistry was used to visualizethe presence of macrophages (CD68) and to examine the MCP-1 andNF-κB expression, so that we can find the relationship betweenmacrophage infiltration and these cytokines. Vascular progressive stenosis with significant atherosclerotic plaqueformation was recognized, showing plaque area in group C larger than ingroup B (p<0.001), while there was no plaque in group A. Inflammatoryresponse was related to the degree of vascular stenosis and plaqueformation. Significant macrophage infiltration in intima was recognized ingroup B and C, mainly appearing in the plaque area. Ratio of IT/media indifferent groups had obvious difference (group B and group C versus groupA, p<0.0001). But there was no difference in the cross sectional area ofmedia. According to the percent of the plaque in the intima, we dividedgroup B and group C into two sub-groups respectively, B1 and B2sub-groups, C1 and C2 sub-groups. Then we found the plaque area andmacrophages counting of B2 and C2 are obvious larger than B1 and C1(p<0.0001 and p<0.00001, respectively). About the macrophage countingin three groups, we found the group B and C is much more than group A.MCP-1 immunoreactivity was found strongly in atherosclerotic plaque ofgroup B and group C, and the same result was found in NF-κB. And therewas positive relationship between MCP-1 and NF-κB. Our study has demonstrated that coronary artery progressive stenosisis caused by intimal hyperplasia. Plaque is the most capital component ofthe intima. Macrophage infiltration in arterial intima plays an importantrole in coronary artery progressive stenosis by plaque formation. MCP-1and NF-κB might regulate this progression. We concluded that the degreeof luminal stenosis much more related to the macrophage infiltration andplaque formation.