Detection of M. paratuberulosis in Crohn's Disease

克罗恩病中副结核分枝杆菌的检测

• 批准号: 8890781
• 负责人: Vivek Kapur
• 金额: $ 16.13万
• 依托单位: PENNSYLVANIA STATE UNIVERSITY, THE
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-08-01 至 2017-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8890781
• 关键词: Address; Animals; Antibodies; Biological Assay; Blinded; Cattle; Characteristics; Chronic; Clinical; Clinical Sensitivity; Collaborations; Collection; Crohn' s disease; Detection; Development; Diagnosis; Diagnostic tests; Disease; Epidemiology; Food Supply; Formalin; Future; Gastrointestinal tract structure; Genetic; Genus Mycobacterium; Goals; Health; Histologic; Human; Human Milk; Immunohistochemistry; Individual; Infection; Inflammatory; Inflammatory Bowel Diseases; Intestinal Diseases; Intestines; Investigation; Letters; Manure; Milk; Molecular; Monoclonal Antibodies; Mus; Mycobacterium Infections; Mycobacterium avium; Mycobacterium tuberculosis; Organism; Paraffin Embedding; Paratuberculosis; Pathogenesis; Patients; Performance; Play; Predisposition; Prevalence; Public Health; Recombinant DNA; Reproducibility; Resources; Role; Ruminants; Sampling; Sensitivity and Specificity; Specificity; Testing; Time; Tissue Sample; Tissues; animal tissue; base; diagnostic assay; enteritis; genome wide association study; genome-wide; human tissue; meetings; mycobacterial; pathogen; prevent; tissue fixing; tool; trend

DESCRIPTION (provided by applicant): Crohn's disease (CD) is a chronic inflammatory disorder of the gastrointestinal tract, and there is strong evidence of considerable overlap between susceptibility loci for CD and mycobacterial infections. Increasing trends of CD are observed worldwide, and it is estimated that there are 400,000-600,000 patients with CD in the US. A clinically and histopathologically similar disease in ruminants, called Johne's disease (JD), is caused by Mycobacterium avium subspecies paratuberculosis (MAP). However, although long hypothesized, the association between MAP and CD remains unproven. This is, in large part, because of a lack of sensitive and specific diagnostic tests that are robust and can be easily applied to screen a sufficiently large number of tissue or clinical samples. After many years of effort, preliminary studies have finally led to the development of a monoclonal antibody (17A12) that specifically recognizes MAP. Hence, we here propose exploratory studies to meet the well-recognized need to develop highly specific and sensitive assays to detect MAP in tissues from CD patients. Two specific aims are proposed. In Aim 1, we will develop and establish performance characteristics of an immunohistochemistry (IHC) assay for the detection of MAP in tissues using the MAP-specific monoclonal antibody, 17A12. The IHC assay will be developed, standardized and validated on a collection of paraffin embedded tissue samples from animals with pluribacillary or pauciacillary infections, and from mice experimentally inoculated with other mycobacteria (M. avium and M. tuberculosis). Performance characteristics such as analytical sensitivity, specificity, precision (repeatability and reproducibility), and accuracy of the newly developed assay will be determined. In Aim 2, we will apply the newly developed IHC assay as a preliminary screen to test intestinal tissue from a convenience sample of CD patients and healthy controls for the presence of MAP and establish initial estimates of analytical and clinical sensitivity and specificity of the newly developed assay. Together, these studies will provide us with a long-needed robust toolkit to specifically detect MAP in tissues from patients with CD, and enable future large scale epidemiologic and mechanistic investigations that can address the association of MAP with CD. In the long-term, the availability of this highly specific and sensitive assay may have important clinical implications for the treatment of CD by enabling the identification of individuals that may benefit from targeted anti- mycobacterial therapy, as well as stimulate the development of control strategies to prevent the contamination of milk and the human food supply with MAP.

描述（由申请人提供）：克罗恩病（CD）是一种胃肠道慢性炎症性疾病，有强有力的证据表明CD和分枝杆菌感染的易感基因座之间存在相当大的重叠。在全球范围内观察到CD的增加趋势，估计美国有400，000 - 600，000例CD患者。反刍动物中的一种临床和组织病理学相似的疾病，称为约翰氏病（JD），由鸟分枝杆菌副结核亚种（MAP）引起。然而，尽管长期假设，MAP和CD之间的关联仍然未经证实。这在很大程度上是因为缺乏灵敏和特异的诊断测试，这些测试是强大的，可以 可以容易地应用于筛选足够大量的组织或临床样品。经过多年的努力，初步研究终于导致特异性识别MAP的单克隆抗体（17 A12）的开发。因此，我们在这里提出了探索性研究，以满足公认的需要，开发高度特异性和灵敏度的测定，以检测MAP组织从CD患者。提出了两个具体目标。在目标1中，我们将开发并确定使用MAP特异性单克隆抗体17 A12检测组织中MAP的免疫组织化学（IHC）试验的性能特征。将在多杆菌或少杆菌感染动物和实验性接种其他分枝杆菌（M. avium和M.肺结核）。将确定新开发试验的性能特征，如分析灵敏度、专属性、精密度（重复性和重现性）和准确度。在目标2中，我们将应用新开发的IHC检测法作为初步筛选，以检测CD患者和健康对照的方便样本中肠组织中是否存在MAP，并建立新开发检测法的分析和临床灵敏度和特异性的初步估计值。总之，这些研究将为我们提供一个长期需要的强大工具包，以特异性检测CD患者组织中的MAP，并使未来的大规模流行病学和机制研究能够解决MAP与CD的关联。从长远来看，这种高度特异性和敏感性的检测方法的可用性可能对CD的治疗具有重要的临床意义，因为它可以识别可能受益的个体， 从有针对性的抗分枝杆菌治疗，以及刺激发展的控制策略，以防止污染的牛奶和人类食品供应与MAP。