P819 Seroprevalence of Borrelia burgdorferi antibodies in patients with ulcerative colitis

Abstract

Abstract Background Lyme disease is a significant zoonotic tick-borne disease with an increasing prevalence in northern hemisphere. The infected tick of the genus Ixodes is responsible for spreading of the disease. Erythema migrans lesions, cranial-nerve (particularlyfacial-nerve) palsy and meningitis, carditis and arthritis are the main manifestations of the disease. Diagnosis of Lyme disease mainly depends on medical history, compatible clinical signs in connection with laboratory findings including more than two IgM bands or more than 5 IgG bands on immunoblot. Ulcerative colitis (UC) is a immun-mediated large bowel disease that is characterised by abdominal pain, bloody diarrhoea and tenesmus due to lymphoplasmocyter infiltration of the mucosal crypts. There have been many studies describing a wide range of genetic, immunologic and environmental risk factors in patients with UC. However, there is no report whether Borrelia burgdorferi antibodies are protective in patients with UC. Methods This was a single centre retrospective observational study of patients with UC vs. age and -matched healthy controls. The medical records of gastroenterology clinic patients with UC between July 2018 and May 2019 were reviewed. At total, 51 (15 female; the mean age 46 years; 35 of them were using anti-TNF agents) UC patients have tested for Borrelia antibodies. On the other hand, 66 age-matched otherwise healthy control subjects (36 female; mean age was 54 years) were selected as comparator group. Results While, only 2 patients (3%) were tested positive for Borrelia bugdorferi (BB) Ig G antibody, 15 subjects (22.7%) had a positive result for BB Ig G antibody in control group. There was a significant difference between groups in terms of BB Ig G seropositivity (p < 0.001). found significantly low rates of BB Ig g seroprevalance in patients with UC. The reason of this phenomenon is unclear. Conclusion The low rate of BB Ig G in patients with UC may have been related to presence of aberrant NK T cells in colonic mucosa. Evidence suggests a inverse link between Lyme arthritis and elevated levels of NK T cells, therefore we hypothesise that UC-related T cells regulates Borrelia trafficking. On the other hand, it has been a well known fact that UC is also related to improvement in sociodemographic development in developing world. Lyme disease is mostly driven by tick exposure in rural areas and mostly seen in forestal areas of the world rather than city centres. This phenomenon may also compatible with real life prevalence models of the inflammatory bowel diseases. In conclusion, these data indicate, for the first time, the inverse association between UC and seropositivity of BB antibodies could lead to design new diagnostic and prognostic tools.