克隆病肠粘膜匀浆诱发地鼠肉芽肿性肠炎

Granulomatous enteritis induced by tissue homogenates of Crohn' sdisease in hamsters

目的探讨副结核杆菌（Ｍｙｃｏｂａｃｔｅｒｉｕｍｐａｒａｔｕｂｅｒｃｕｌｏｓｉｓ，Ｍｐ）在克隆病（Ｃｒｏｈｎ＇ｓｄｉｓｅａｓｅ，ＣＤ）病因学中的作用．方法将５例ＣＤ患者肠道的活检组织制成匀浆，１００μＬ作ＰＣＲ分析，４０μＬ接种地鼠肠壁后４ｍｏ，作肉眼和组织学观察，炎症程度评分按Ｔａｎａｋａ的肠道损伤积分标准．结果５例ＣＤ肠粘膜匀浆中，有２例扩增出Ｍｐ４００ｂｐ的ＤＮＡ片段．用ＰＣＲ阳性组ＣＤ匀浆接种１０只地鼠后，有５只出现了肉芽肿性改变，并再次ＰＣＲ扩增检出了Ｍｐ．ＰＣＲ阳性组肠道损伤平均积分为４８±２４；ＰＣＲ阴性组仅有１只出现肉芽肿性炎症，积分为３７±１７，两组无显著性差异（Ｐ＞００５）；而两组动物肉芽肿性肠炎的发病率有显著性差异（Ｐ＜００５）；ＣＤ匀浆组和正常肠粘膜组的积分有显著性差异（Ｐ＜００５）．结论Ｍｐ确实可能为部分ＣＤ的致病菌．

AIM To investigate whether Mycobacterium paratuberculosis (Mp) plays an etiologic role in Crohn's disease (CD). METHODS One hundred L homogenates of intestinal biopsy tissue from CD patients was analysed by PCR, and 40 L homogenates was inoculated intramurally into the cecum and terminal ileam of each hamsters (n=5), tissues from two inoculated segment of ileum and cecum were obtained and evaluated macroscopically and histologically after 4 months. Each hamster was scored on the criteria for assessment of intestinal damage. RESULTS Two of five CD homogenates were positive for Mp. The 5 of 10 hamsters receiving PCR positive CD homogenates developed mucosal ulceration and granulomatous changes. The correct 400bp amplification product was obtained again in the granulomatous intestinal tissues of 5 hamsters inoculated PCR positive CD homogenates when the IS900 PCR was applied. The average score of hamsters intestinal damage induced by PCR negative CD homogenates was 37 17 which markedly increased as compared with those of normal gut mucosa group(P<005); but no statistically significant difference was shown when compared with PCR positive CD homogenates group. CONCLUSION Mp possibly plays an etiologic role in at least some cases of Crohn' s disease.