Halstensen T S, Mollnes T E, Garred P, Fausa O, Brandtzaeg P
Laboratory for Immunohistochemistry and Immunopathology (LIIPAT), Institute of Pathology, Oslo, Norway.
Gut. 1992 Jul;33(7):902-8. doi: 10.1136/gut.33.7.902.
IgG1 and activated complement are colocalised on the colonic epithelial brush border in active ulcerative colitis. To investigate whether such deposition is specific for ulcerative colitis, we examined ethanol fixed mucosal specimens from 18 patients with Crohn's colitis and 14 with terminal ileitis by indirect two colour immunofluorescence staining. Monoclonal antibodies to the IgG subclasses and to neoepitopes of activated complement C3b and the terminal complement complex were used in combination with rabbit antiserum to C1q, C4c or cytokeratin. Granular deposition of C3b and terminal complement complex were observed at the luminal face of the surface epithelium in 10 of 18 patients with Crohn's colitis. Specimens from eight of 14 patients with ileal involvement were intensely stained for activated complement (primarily C3b) within the surface mucus layer. No epithelial IgG, C1q or C4c deposition was observed. The results suggest that early and late phase complement activation takes place at the luminal face of the epithelium in Crohn's disease. The absence of colocalised IgG and complement components involved in the classical activation pathway (C1q and C4c), however, suggest that other immunopathological mechanisms (the alternative pathway?) are primarily involved in Crohn's disease in contrast with ulcerative colitis.
在活动性溃疡性结肠炎中，IgG1和活化补体共定位于结肠上皮刷状缘。为了研究这种沉积是否为溃疡性结肠炎所特有，我们通过间接双色免疫荧光染色检查了18例克罗恩病结肠炎患者和14例末端回肠炎患者的乙醇固定黏膜标本。将针对IgG亚类以及活化补体C3b和末端补体复合物新表位的单克隆抗体与兔抗C1q、C4c或细胞角蛋白抗血清联合使用。在18例克罗恩病结肠炎患者中的10例患者的表面上皮腔面观察到C3b和末端补体复合物的颗粒状沉积。14例累及回肠的患者中有8例的标本在表面黏液层内有强烈的活化补体（主要是C3b）染色。未观察到上皮IgG、C1q或C4c沉积。结果表明，在克罗恩病中上皮腔面发生早期和晚期补体激活。然而，经典激活途径中涉及的IgG和补体成分（C1q和C4c）未共定位，这表明与溃疡性结肠炎相比，其他免疫病理机制（替代途径？）在克罗恩病中起主要作用。
