Kuzminets A. The diagnostic capabilities of non-invasive biomarkers for drug-induced intestinal lesions in patients with osteoarthritis

The dissertation is devoted to the study of non-invasive biomarker diagnostic capabilities for drug - induced intestinal lesions in patients with osteoarthritis. Osteoarthritis (OA) is the most common musculoskeletal disease. It is a potentially disabling disease, associated with a higher mortality rate than in a similar population without osteoarthritis[1]. It is also associated with a higher prevalence of gastrointestinal diseases (GI), which is mainly due to the frequent use of non-steroidal anti-inflammatory drugs (NSAIDs) by these patients [2]. According to the literature, NSAID-induced lower gastrointestinal lesions, are no less common than upper lesions, often asymptomatic [3], and can lead to malabsorption and nutrient deficiency, chronic protein loss and blood loss, and, in severe cases, to various types of intestinal obstruction. [3]. At present, there are no generally accepted non-invasive markers of NSAID-induced intestinal lesions, and the "gold standard" for the diagnosis of NSAID entero- and colopathy are invasive studies - video capsule endoscopy and colonoscopy, respectively. However, NSAID-induced lesions of the lower gastrointestinal tract, in contrast to those of the upper, are much less studied and do not have generally accepted recommendations for their treatment and prevention [4]. In the dissertation, the possibility of using non-invasive indicators is studied - fecal biomarkers of calprotectin, secretory immunoglobulin A, and hemoglobin/haptoglobin complex - in the diagnosis of NSAID-induced intestinal lesions and changes in the intestinal microbiome associated with such lesions. Aim of the research: Improvement of the diagnosis of drug-induced intestinal lesions in patients with osteoarthritis by studying the diagnostic capabilities of non-invasive fecal biomarkers of such lesions. Objectives of the research: 1. To study the prevalence and structure of changes in fecal biomarkers of inflammation (fecal - calprotectin, secretory immunoglobulin A, hemoglobin/haptoglobin complex) in patients with osteoarthritis. 2. To study the peculiarities of changes in the composition of the fecal microbiome (FM) as a non-invasive marker of intestinal lesions in patients with osteoarthritis, as well as to establish the relationship between the composition of the FM and laboratory indicators of intestinal wall inflammation. 3. To investigate the relationship between the intake of NSAIDs of varying degrees of selectivity and the presence of intestinal lesions as established by biochemical indicators. 4. To investigate the relationship between the intake of NSAIDs of varying degrees of selectivity and the composition of the FM. 5. To develop a statistical model for predicting the presence of NSAID-induced lesions in terms of non-invasive biomarkers.