(DOWNLOAD) "Biomarkers for Inflammatory Bowel Disease (Clinical PRACTICE)" by Clinical Laboratory Science # eBook PDF Kindle ePub Free
eBook details
- Title: Biomarkers for Inflammatory Bowel Disease (Clinical PRACTICE)
- Author : Clinical Laboratory Science
- Release Date : January 22, 2007
- Genre: Engineering,Books,Professional & Technical,
- Pages : * pages
- Size : 177 KB
Description
Over the past ten years, the field of gastroenterology has seen the rapid development of commercially available diagnostic serological tests for a variety of intestinal diseases. Laboratory assays are routinely used to help diagnose conditions such as celiac disease, H. pylori infection, malabsorption, colon cancer, Zollinger Ellison syndrome, and others. More recently, biomarkers used to assist in the diagnosis of inflammatory bowel disease (IBD) have been studied. IBD refers to a heterogeneous group of disorders of unclear etiology but sharing common histopathological features. IBD patients have chronic intestinal mucosal inflammation at the microscopic level with the potential for macroscopic and extra-intestinal inflammation. IBD is divided into three entities: ulcerative colitis (UC), Crohn's disease (CD), and indeterminate colitis. UC is a chronic inflammatory disorder of the colonic mucosa which occurs from the anus and can extend proximally to involve the entire colon. In contrast, CD is a chronic inflammatory disorder that can occur anywhere from the mouth to the anus in a patchy distribution, involving the full thickness of the intestine. Currently, despite complete clinical, endoscopic, radiologic, and pathologic evaluations, 10% to 15% of adult patients with IBD cannot be differentiated; these patients fall into the category of indeterminate colitis. The clinical importance of distinguishing CD from UC is threefold: (1) defining pathogenesis, (2) guiding treatment regimens, and (3) predicting prognosis. The Crohn's and Colitis Foundation of America estimates that approximately one million Americans have IBD, evenly distributed between CD and UC, with ten percent classified as having indeterminate colitis. In the US pediatric population it is estimated that approximately 100,000 children carry the diagnosis of IBD. There has been a particular push to develop biomarkers for UC and CD in pediatric patients so that invasive procedures (colonoscopy/endoscopy) can be avoided in children. The pathogenesis of IBD remains poorly understood. It has been hypothesized that the observed chronic inflammation may be the result of a dysfunctional immune response to gut bacteria. The exploration of the relationship between enteric bacteria and the human immune response has led to the development of several assays that detect the presence of antibodies to specific bacterial antigens. Note that none of these tests have been shown to have any direct pathophysiological significance. In clinical practice, the combination of these assays may be most useful when the results of other appropriate diagnostic evaluations are inconclusive. As of yet, none of these tests are appropriate for use in for general population screening. It should also be noted that many of the reported sensitivities and specificities of these tests are based on study populations with high disease prevalence, ranging from 42%-68%. (1) The spectrum of patients is thus very important when considering the value of new IBD biomarkers since factors like duration and severity could affect diagnostic sensitivity and specificity. In general, biomarkers for IBD have better specificity than sensitivity. They are typically more useful in the differentiation between UC and CD in IBD patients and less useful in detecting IBD in presenting patients. Currently available serological tests that evaluate specific microbial or leukocyte antigens include the following: