Comparing techniques to achieve high accuracy and low cost: how should we first diagnose Crohn's disease?

Abstract

Background Crohn’s disease (CD) is a life-long inflammatory disease, which may involve the whole gastrointestinal tract. Both its incidence and prevalence are increasing around the world, with an annual incidence ranging from 12.7 to 20.2 per 100,000 person-years, respectively, in Europe and North America, and a prevalence ranging from 319 to 322 per 100,000 persons [1]. Disease onset usually happens in the second or in the third decade of life, but a significant increase in incidence in pediatric population has been reported in recent years. The first symptoms of CD – abdominal pain and diarrhea – may be interpreted as those of other gastrointestinal disorders, such as particularly irritable bowel syndrome. Irritable bowel syndrome is more frequent (10–50-times) than CD and it is an important cause of symptoms (30–50%) in patients with CD [2,3]. The general rise in healthcare standards and the improvement in diagnostic tools, as well as the general awareness of inflammatory bowel disease (IBD) both by physicians and the public have led, in recent years, to an increasing demand for diagnostic investigations in adults and in young patients with abdominal symptoms, resulting in a significant impact on the healthcare system costs [2]. Diagnosis of CD: reality & clinical guidelines The diagnosis of intestinal diseases in patients with abdominal complaints may be challenging. A single gold standard for CD diagnosis is not available. Ileocolonoscopy with biopsies from the terminal ileum and colonic segments is the main diagnostic procedure [4]. However, this may not be the preferred tool approach for an initial investigation in pediatric setting; moreover, it is not possible to achieve the ileum in 5–15% of the patients [5]. According to recent European Crohn’s and Colitis Organisation’s guidelines [6] CRP, full blood count and fecal calprotectin should be performed before endoscopy in patients with symptoms compatible with CD. In addition to that, irrespective of the findings by ileocolonoscopy, further examinations are recommended in order to confirm CD diagnosis, its location, extent and complications [6,7]. In this regard, international guidelines have recognized that high-resolution intestinal ultrasonography (IUS), computed tomography enterography (CTE) and magnetic resonance enterography (MRE) have comparable diagnostic accuracy for the initial assessment of CD [8]. Before these investigations, biomarkers like fecal calprotectin have been suggested for “The diagnosis of intestinal diseases in patients with abdominal complaints may be challenging. A single gold standard for Crohn’s disease diagnosis is not available.”