Irritable bowel syndrome: extra- intestinal comorbidity, psychological, morphometric and genetic predictors of variants of the course of the disease

Purpose of the study. To determine clinical, morphometric, genetic predictors of non-refractory and refractory variants of the course of irritable bowel syndrome (IBS).Materials and methods. We examined 148 patients with non-refractory (41 people) and refractory (107 people) the course of irritable bowel syndrome. The control group consisted of 36 healthy volunteers. The analysis of the symptoms of the current exacerbation of the disease, verifi cation of comorbid gastroenterological pathology (taking into account the Roman criteria- IV and Russian recommendations), assessment of signs of psychological maladaptation (The Four-D imensional Symptom Questionnaire), fi brocolonoscopy, immunohistochemical, morphometric study of colobiopts, determination of the expression area of colonocytes immunopositive to motilin and sirtuin-1, determination of genotypes of polymorphic marker rs4680 of the СOMT gene by polymerase chain reaction.Results. The intensity of abdominal pain, the severity of “intestinal” symptoms was higher in refractory IBS compared with non-refractory. Functional comorbidity (functional dyspepsia, functional disorder of the gallbladder) was more common in the refractory variant of the course of the disease, mainly with diarrhea. Indicators of distress, depression, anxiety, somatization in the refractory course of the disease were higher compared to non-refractory, did not diff er signifi cantly in IBS with constipation and diarrhea. The indicators of the expression area of motilin-p ositive colonocytes were reduced in IBS with constipation, increased in IBS with diarrhea (the maximum changes were in the refractory variant of the course of the disease). The expression area of sirtuin-1-positive colonocytes was reduced in IBS with diarrhea compared to IBS with constipation and with the control group. Associations of genotypes of the polymorphic marker rs4680 of the СOMT gene with a refractory variant of the course of IBS, as well as with the severity of abdominal pain syndrome and signs of psychological maladaptation were found.Conclusion. Patients with irritable bowel syndrome are characterized by functional comorbidity, signs of psychological maladaptation, more pronounced in the refractory variant of the course of the disease. Patients with IBS, in comparison with the control group, are characterized by a change in the expression area of motilin- and sirtuin-1-positive colonocytes, correlating with the variant of intestinal dysfunction and maximally expressed in the refractory course of the disease. Variants of the course of irritable bowel syndrome are associated with polymorphic markers rs4680 of the gene of the enzyme СOMT.