Serum anti-glycan-antibodies in relatives of patients with inflammatory bowel disease

BackgroundSerum anti-glycan antibodies are a promising tool for differential diagnosis, disease stratification and prediction of Crohn’s disease (CD). To investigate possible heritability of the markers we assessed the presence of serum anti-glycan antibodies in affected and unaffected relatives of patients with CD.MethodsSerum samples of 169 IBD patients of the German inflammatory bowel disease (IBD) network (140 CD & 29 Ulcerative colitis (UC)), 349 relatives of CD patients, 63 relatives of UC patients and 46 healthy controls were tested for the presence of anti-glycan antibodies by ELISA in a blinded fashion. Clinical data of the IBD patients and controls were available.ResultsA higher proportion of non-affected CD relatives was positive for anti-glycan antibodies compared to healthy subjects. No inheritance of a specific pattern of anti-glycan antibodies could be detected. No difference in marker expression depending on the degree of relationship in the non-affected relatives was noted and the presence of family history did not lead to a difference in marker levels in the affected CD subjects.ConclusionsNon-affected CD relatives had a higher frequency of anti-glycan antibodies compared to healthy subjects. This difference was mild and was found to be true for the overall reactivity to glycan antigens, but not for specific patterns. This may indicate an inherited mechanism resulting in a non-specific increased reactivity to microbial antigens in IBD.

Background
血清抗聚糖抗体是克罗恩病（Crohn’s disease, CD）鉴别诊断、疾病分层与预测的潜在有力工具。为探究该标志物的潜在遗传特性，我们对克罗恩病患者的患病及未患病亲属体内的血清抗聚糖抗体水平进行了检测。

Methods
本研究采用盲法酶联免疫吸附试验（ELISA），检测了以下样本的抗聚糖抗体存在情况：德国炎症性肠病（inflammatory bowel disease, IBD）网络收录的169名IBD患者（其中140例克罗恩病患者、29例溃疡性结肠炎（Ulcerative colitis, UC）患者）、349名克罗恩病患者亲属、63名溃疡性结肠炎患者亲属以及46名健康对照。同时可获取所有IBD患者与对照的临床数据。

Results
与健康受试者相比，未患病的克罗恩病亲属抗聚糖抗体阳性比例更高。未检测到抗聚糖抗体特定模式的遗传传递现象。在未患病亲属群体中，标志物表达水平与亲缘关系程度无显著差异；且存在家族史的克罗恩病患者与无家族史者相比，其标志物水平亦无明显差异。

Conclusions
相较于健康受试者，未患病的克罗恩病亲属抗聚糖抗体阳性频率更高。该差异程度较轻，且仅体现在对聚糖抗原的整体反应性上，而非特定抗体模式。这一结果提示，炎症性肠病（IBD）患者体内可能存在一种遗传机制，使其对微生物抗原产生非特异性的反应性增强。