Stainsby K J, Lowes J R, Allan R N, Ibbotson J P
Department of Microbiology, University College Hospital, Medical School, London.
Gut. 1993 Mar;34(3):371-4. doi: 10.1136/gut.34.3.371.
Cultural and serological studies have provided limited, often conflicting, evidence of a role for mycobacteria in the pathogenesis of Crohn's disease. Interest has focussed on Mycobacterium paratuberculosis, previously considered to be common in the environment with no major role as a human pathogen. Whether a specific serum antibody response to mycobacteria occurs in Crohn's disease or ulcerative colitis was investigated. Sera from patients with Crohn's disease (n = 38), ulcerative colitis (n = 15), and a healthy control population (n = 30) were assayed in an enzyme linked immunosorbent assay (ELISA) using eight filtered sonicate mycobacterial preparations and a purified protein derivative made from the bovine tubercle bacillus. In addition, IgG, IgM, and IgA levels to M paratuberculosis were determined in sera from patients with active (n = 24) or inactive (n = 29) Crohn's disease and the control populations. There was strong evidence of contact with environmental mycobacteria in all patients and control populations, with the greatest responses to preparations of M avium, M tuberculosis, and M kansasii. A large proportion of patients with Crohn's disease had antibodies that bound most antigens tested but there were no statistical differences between these values and those of the control population. Similarly, there were no differences in antibody levels to M paratuberculosis in patient and control groups. Although a subset of patients with active Crohn's disease (25%) had IgG concentrations that exceeded the control mean by more than 2 SD, this phenomenon may not be specific to Crohn's disease: 20% of a small group of patients with coeliac disease had similarly raised IgG levels to M paratuberculosis. These findings do not provide serological evidence of a role for this organism in the pathogenesis of Crohn's disease.
文化和血清学研究提供了有限的、常常相互矛盾的证据，证明分枝杆菌在克罗恩病发病机制中的作用。人们的兴趣集中在副结核分枝杆菌上，该菌以前被认为在环境中很常见，但作为人类病原体没有主要作用。研究了克罗恩病或溃疡性结肠炎患者是否会出现针对分枝杆菌的特异性血清抗体反应。使用八种经过滤的分枝杆菌超声破碎制剂和一种由牛结核杆菌制成的纯化蛋白衍生物，通过酶联免疫吸附测定（ELISA）对克罗恩病患者（n = 38）、溃疡性结肠炎患者（n = 15）和健康对照人群（n = 30）的血清进行检测。此外，还测定了活动期（n = 24）或非活动期（n = 29）克罗恩病患者及对照人群血清中针对副结核分枝杆菌的IgG、IgM和IgA水平。所有患者和对照人群都有与环境分枝杆菌接触的有力证据，对鸟分枝杆菌、结核分枝杆菌和堪萨斯分枝杆菌制剂的反应最为强烈。很大一部分克罗恩病患者的抗体能结合大多数检测的抗原，但这些值与对照人群的值之间没有统计学差异。同样，患者组和对照组针对副结核分枝杆菌的抗体水平也没有差异。虽然一小部分活动期克罗恩病患者（25%）的IgG浓度超过对照平均值2个标准差以上，但这种现象可能并非克罗恩病所特有：一小群乳糜泻患者中有20%针对副结核分枝杆菌的IgG水平也有类似升高。这些发现没有提供该生物体在克罗恩病发病机制中起作用的血清学证据。
