Milton S Hershey Medical Center, Penn State College of Medicine, 500 University Dr, Hershey, PA, 17033, USA.
Division of Gastroenterology and Hepatology, Penn State Milton S Hershey Medical Center, 500 University Dr, Hershey, PA, 17033, USA.
Clin Rev Allergy Immunol. 2019 Oct;57(2):179-193. doi: 10.1007/s12016-018-8690-3.
Inflammatory bowel disease (IBD) is a chronic immune-mediated inflammatory condition primarily involving the gastrointestinal tract. It includes Crohn's disease (CD), ulcerative colitis (UC), and a less common phenotype-indeterminate colitis. It is thought to result from a complex interplay of environmental, microbial, and host factors including genetic factors, although the exact mechanism is not known. Dietary factors have been shown to play a role in the pathogenesis of IBD and can potentially alter the intestinal microbiota as well as disrupt the immune function in the gut. CD is characterized by transmural inflammation, sometimes associated with granulomatous lesions, and involves the entire gastrointestinal tract but often spares the rectum. UC is characterized by mucosal inflammation typically confined to the colon and rectum. Although IBD is mostly seen in western world, recent data suggests that the incidence and prevalence are increasing worldwide. Enteral nutrition has been shown to be effective in inducing remission in pediatric population with CD; however, there is mixed data in adult population. Nutritional deficiencies such as vitamin D and zinc deficiency are often noted in IBD patients. Several extraintestinal manifestations are noted in patients with IBD. Some of them parallel with the disease activity and others are independent of the disease course. Assessment of IBD disease activity clinically, radiologically, if indicated, biochemically and endoscopically is important to guide therapy in IBD. To ensure comprehensive care, it is important to assess associated conditions such as nutritional and psychological well-being, as well as age appropriate health maintenance status prior to starting treatment for IBD. Several biologic agents including anti-tumor necrosis factor alpha (anti-TNF-α) drugs, anti-integrins, and antibodies to the p40 subunit of IL12/23 are approved for induction and maintenance of remission of IBD. Steroids are also often used for induction. Anti-metabolites and thiopurines are also useful either as monotherapy or in combination regimens. Potential side effects of anti-TNF-α drugs such as serious infections, malignancy, worsening of heart failure, and infusion-related reactions should be considered prior to starting these drugs. Anti-TNF-α drugs with or without immunomodulators (azathioprine, 6-mercaptopurine, methotrexate) are often used for the induction and maintenance of remission. Treating to target of endoscopic and clinical remission provides the best long-term outcomes. Our knowledge and understanding of IBD has grown significantly. However, there are several unanswered questions on pathogenesis, disease behavior, and drivers of inflammation in various patient subgroups which require further research.
炎症性肠病（IBD）是一种主要涉及胃肠道的慢性免疫介导的炎症性疾病。它包括克罗恩病（CD）、溃疡性结肠炎（UC）和一种不太常见的表型不确定结肠炎。据认为，它是由环境、微生物和宿主因素（包括遗传因素）的复杂相互作用引起的，尽管确切的机制尚不清楚。饮食因素已被证明在 IBD 的发病机制中起作用，并可能改变肠道微生物群并破坏肠道中的免疫功能。CD 的特征是透壁性炎症，有时伴有肉芽肿性病变，涉及整个胃肠道，但通常不涉及直肠。UC 的特征是黏膜炎症，通常局限于结肠和直肠。尽管 IBD 主要见于西方国家，但最近的数据表明，其发病率和患病率在全球范围内都在增加。肠内营养已被证明在诱导 CD 儿科患者缓解方面有效；然而，在成人中数据存在差异。IBD 患者常出现维生素 D 和锌等营养缺乏。在患有 IBD 的患者中还注意到几种肠外表现。其中一些与疾病活动平行，另一些则与疾病过程无关。临床上、放射学上（如果有指征的话）、生化和内镜下评估 IBD 疾病活动对于指导治疗非常重要。为了确保全面的护理，在开始治疗 IBD 之前，评估相关疾病，如营养和心理健康状况，以及年龄适当的健康维持状况非常重要。几种生物制剂，包括抗肿瘤坏死因子-α（anti-TNF-α）药物、抗整合素和抗 IL12/23 的 p40 亚单位抗体，已被批准用于诱导和维持 IBD 的缓解。类固醇也常用于诱导。抗代谢物和硫嘌呤也可单独使用或联合使用。在开始使用这些药物之前，应考虑 anti-TNF-α 药物的潜在副作用，如严重感染、恶性肿瘤、心力衰竭恶化和输注相关反应。anti-TNF-α 药物联合或不联合免疫调节剂（硫唑嘌呤、6-巯基嘌呤、甲氨蝶呤）通常用于诱导和维持缓解。达到内镜和临床缓解的治疗目标可提供最佳的长期结果。我们对 IBD 的认识和理解有了显著的提高。然而，在各种患者亚组中，关于发病机制、疾病行为和炎症驱动因素仍有几个悬而未决的问题，需要进一步研究。
