肺炎衣原体与动脉粥样硬化关系的病理学探讨

Relationship between detection of Chlamydia pneumoniae DNA in human coronary artery and extent of atherosclerosis

目的近年来感染作为动脉粥样硬化(AS)发病的新的危险因素受到格外关注,特别是肺炎衣原体(C.pn)感染和AS两者是否具有因果关系一直是争议的焦点。本研究试从病理学的角度探讨C.pn在动脉组织检出的意义及其在AS发生发展过程中的作用。方法利用高灵敏度的nestedPCR法对90例尸检材料采取的右冠状动脉(RCA)组织切片进行C.pn检测,同时根据美国心脏学会的AS组织学分类标准将所有标本进行分类。结果使用Nested PCR法除正常RCA之外在不同程度的AS病变组织中均有C.pn特异性DNA片段检出。90例中C.pn阳性检出率为48%(43/90),其中心脑血管病死因组为50%(15/30),其他死因组为41%(28/60),C.pn阳性检出组和阴性对照组的尸检患者临床特征如性别比例、死亡时的平均年龄及是否为心血管病死因等进行对照分析,结果显示均无显著性差异。在对90个标本4个病变内膜组中C.pn阳性检出率进行对照分析的结果显示,C.pn阳性检出率在病变初期组高于进展组,但随病变程度的增强却有意义的呈现低值。结论本研究结果提示C.pn普遍存在于AS的各类病变中,C.pn感染可能是AS形成初期阶段的启始因子,但对AS病变的发展没有直接的促进作用。

Objective Recently numerous studies have suggested Chlamydia pneumoniae(C.pn)as a possible candidate for infectious agents in the etiology of atherosclerosis. However, it is still unclear whether C.pn plays a causal role in this disease and its sequelae. Accordingly, right coronary arteries (RCA) on autopsied subjects were examined with molecular biological detection method and standard histopathological method to determine the role of C.pn in atherosclerosis development. Methods C.pn DNA in RCA segments from 90 autopsied patients (30 cases with cardiovascular disease and 60 cases free from cardiovascular disease) was detected by a sensitive nested polymerase chain reaction (PCR). Each segment was classified by the standard of American Heart Association. Results C.pn was detected in 48% (43/90) of subjects, 50% (15/30) in cardiovascular death group and 41% (29/60) in noncardiovascular death group. There was no significant difference between with and without cardiovascular disease groups. Furthermore, there was no statistical difference in age, sex, or cause of death in subjects with or without C.pn DNA in their RCA. Among the four intimal lesion groups, the frequency of C.pn detection was highest in the fatty streak lesion, which is characteristic of developing atherosclerosis, and thereafter decreased with progression of atherosclerosis. Conclusion This autopsy study demonstrated that C.pn can be a common finding in the atherosclerotic lesions. C.pn infection may play an initiating role in atherosclerosis development, but it did not correlate with progression of intimal lesion in RCA.