[Modern concept of differential diagnosis of colitis: from G.F. Lang to the present day. A review].

The aim of the article is to improve the differential diagnosis of specific and nonspecific inflammatory bowel diseases. In Russia, this scientific direction is associated with the name of G.F. Lang, who performed in 1901-1902 the study "On ulcerative inflammation of the large intestine caused by balantidiasis". The etiology of specific colitis is associated with infection with parasites, bacteria and viruses that cause inflammation of the intestinal wall, diarrhea, often with an admixture of mucus, pus and blood. Specific colitis (SC) may be accompanied by fever, abdominal pain, and tenesmus. Bacterial colitis is commonly caused by Salmonella, Shigella, Escherichia coli, Clostridium difficile, Campylobacter jejuni, Yersinia enterocolitica, and Mycobacterium tuberculosis. Viral colitis is caused by rotavirus, adenovirus, cytomegalovirus, and norovirus. Parasitic colitis can be caused by Entamoeba histolytica and balantidia. In gay people, SC can cause sexually transmitted infections: Neisseria gonorrhoeae, Chlamydia trachomatis, and treponema pallidum, affecting the rectum. Stool microscopy, culture, and endoscopy are used to establish the diagnosis. Stool culture helps in the diagnosis of bacterial colitis in 50% of patients, and endoscopic studies reveal only nonspecific pathological changes. Differential diagnosis of SC should be carried out with immune-inflammatory bowel diseases (ulcerative colitis, Crohn's disease, undifferentiated colitis), radiation colitis and other iatrogenic bowel lesions. The principles of diagnosis and therapy of inflammatory bowel diseases associated with various etiological.

[Tuberculosis infection in patients with inflammatory bowel diseases. Clinacal cases].

In most cases Tuberculosis (TB) affects the lungs, but 10-15% of patients have extrapulmonary TB localisations, that is difficult to diagnose. TB is more spread among patients having the human immunodeficiency virus and among those who receive immunosuppressive therapy, specifically in patients with inflammatory bowel disease requiring long-term treatment with immunosuppressants and/or biologics. The symptoms of intestinal TB are nonspecific and may include chronic diarrhea, weight loss, fever and ascites. Differential diagnosis includes Crohn's disease, malignant neoplasms, periappendiceal abscesses, yersiniosis, etc. The article presents cases showing similarity of the intestinal form of TB with Crohn's disease, complexity dealing, diagnosing and treating patients with inflammatory bowel disease also having latent tuberculosis infection.

[Loss of response and frequency of adverse events in patients with ulcerative colitis and Crohn's disease when switching from the original infliximab to its biosimilars].

AIM: To define the frequency of adverse events and loss of the response in patients with ulcerative colitis (UC) and Crohn's disease (CD), treated with original medicine infliximab (IFX) "Remicaide" and its biosimilars. MATERIALS AND METHODS: We included 154 patients with IBD: 78 UC patients (50.6%) и 76 CD patients (49.4%), treated with original medicine IFX Remicade and its biosimilars. In our study we did not include patients, who previously underwent induction treatment with IFX and its biosimilar. RESULTS: Among 78 UC patients, IFX was cancelled in 25 (32.0%) patients and they were switched to the other anti-TNF inhibitor or medicine with the another mechanism of action; in patients group, treated with biosimilar ­ 16 (20.5%) and 9 (11.5%) patients, who were interchanged biosimilar and/or original IFX. Among 76 CD patients IFX was cancelled in 20 (26.3%) patients: 11 (14.5%) patients in group, treated with similar trade name biosimilar, 8 (10.5%) patients, who were interchanged biosimilar and/or original IFX and 1 patient (1,3%), receiving original IFX. We found no difference in the secondary loss of response and adverse events in patients with CD and UC, switched from original IFX to biosimilar (p=0.6257 and p=0.6635, correspondingly). The frequency of the secondary loss of response or adverse events in patients with UC and CD, switched from original IFX to IFX biosimilar, was similar (p>0.05). CONCLUSION: Approximately 30% of IBD patients, receiving IFX biosimilar, will be switched to the other anti-TNF therapy or medicine with the another mechanism of action because of secondary loss of response or adverse events.