Jansen Anke, Mandić Ana D, Bennek Eveline, Frehn Lisa, Verdier Julien, Tebrügge Irene, Lutz Holger, Streetz Konrad, Trautwein Christian, Sellge Gernot
a Department of Internal Medicine III , University Hospital RWTH Aachen , Aachen , Germany.
Scand J Gastroenterol. 2016 Dec;51(12):1453-1461. doi: 10.1080/00365521.2016.1205130. Epub 2016 Jul 25.
Inflammatory bowel disease (IBD), particularly Crohn's disease (CD), is associated with increased microbial-specific IgG and IgA antibodies, whereas alterations of anti-food antibodies are still disputed. The knowledge about IgG subclass antibodies in IBD is limited. In this study we analysed IgG subclass antibodies specific for nutritional and commensal antigens in IBD patients and controls.
Serum IgG1, IgG2, IgG3 and IgG4 specific for wheat and milk extracts, purified ovalbumin, Escherichia coli and Bacteroides fragilis lysates and mannan from Saccharomyces cerevisiae were analysed by ELISA in patients with CD (n = 56), ulcerative colitis (UC; n = 29), acute gastroenteritis/colitis (n = 12) as well as non-inflammatory controls (n = 62).
Anti-Saccharomyces cerevisiae antibodies (ASCA) of all IgG subclasses and anti-B. fragilis IgG1 levels were increased in CD patients compared to UC patients and controls. The discriminant validity of ASCA IgG2 and IgG4 was comparable with that of ASCA pan-IgG and IgA, whereas it was inferior for ASCA IgG1/IgG3 and anti-B. fragilis IgG1. Complicated CD defined by the presence of perianal, stricturing or penetrating disease phenotypes was associated with increased ASCA IgG1/IgG3/IgG4, anti-B. fragilis IgG1 and anti-E. coli IgG1 levels. Anti-food IgG subclass levels were not different between IBD patients and controls and did not correlate with food intolerance. In contrast to anti-microbial Abs, food-specific IgG responses were predominately of the IgG4 isotype and all food-specific IgG subclass levels correlated negatively with age.
Our study supports the notion that the adaptive immune recognition of food and commensal antigens are differentially regulated.
炎症性肠病（IBD），尤其是克罗恩病（CD），与微生物特异性IgG和IgA抗体增加有关，而抗食物抗体的改变仍存在争议。关于IBD中IgG亚类抗体的知识有限。在本研究中，我们分析了IBD患者和对照组中针对营养和共生抗原的IgG亚类抗体。
通过酶联免疫吸附测定法（ELISA）分析了56例CD患者、29例溃疡性结肠炎（UC）患者、12例急性胃肠炎/结肠炎患者以及62例非炎症对照组血清中针对小麦提取物、牛奶提取物、纯化卵清蛋白、大肠杆菌和脆弱拟杆菌裂解物以及酿酒酵母甘露聚糖的IgG1、IgG2、IgG3和IgG4。
与UC患者和对照组相比，CD患者中所有IgG亚类的抗酿酒酵母抗体（ASCA）和抗脆弱拟杆菌IgG1水平均升高。ASCA IgG2和IgG4的判别效度与ASCA全IgG和IgA相当，而ASCA IgG1/IgG3和抗脆弱拟杆菌IgG1的判别效度较差。由肛周、狭窄或穿透性疾病表型定义的复杂性CD与ASCA IgG1/IgG3/IgG4、抗脆弱拟杆菌IgG1和抗大肠杆菌IgG1水平升高有关。IBD患者和对照组之间抗食物IgG亚类水平无差异，且与食物不耐受无关。与抗微生物抗体相反，食物特异性IgG反应主要为IgG4同种型，且所有食物特异性IgG亚类水平与年龄呈负相关。
我们的研究支持食物和共生抗原的适应性免疫识别受到不同调节这一观点。
