Role Of Interleukin-10 Gene Polymorphism In Irritable Bowel Syndrome

BackgroundIrritable Bowel Syndrome (IBS) is a common functional bowel disorder affecting a substantial propertion of the population; point prevalence estimates usually range from 5%-30%. Prevalence rates vary significantly between countries. The etiology of IBS is complex and appears to be multifactorial, involving altered intestinal motility, increased visceral sensitivity, psychosocial factors,mucosal inflammation, diery intolerance and so on. Recently many research found Irritable bowel syndrome patients aggregates in families, perhaps this is due to genetic factors. Some investigators have proposed chronic low-grade mucosal inflammation as a potentialetiological factor of IBS. Interleukin 10 (IL-10) is one of the most important anti-inflammatory cytokine,there exist gene polymorphysm in the promoter region of the IL-10. As the elaboration of cytokines is under genetic control,there might be a genetic predisposition to an altered pattern of anti-inflammatorycytokine production in patients with irritable bowel syndrome. This study was designed to establish whether there might be a genetic predisposition to an altered pattern of IL-10 production in patients with irritable bowel syndrome of guang dong population.Objectives:To investigate the gene polymorphism -1082 G/A and -819 C/T in the IL-10 promoter region and their relationship to IBS in Chinese patients.Methods:Three hundred and thirteen patients with IBS diagnosed according to Romeâ…¢criteria and 321 healthy controls were enrolled to this study. Blood samples were taken from the patients and controls,then genome DNA was extracted from the blood , and then IL-10 gene DNA was amplifiedd by polymerase chain reaction (PCR) ,Their IL-10-1082 and IL-10-819 genotypes were detected by PCR- restriction fragment length polymorphism analysis.Results:There were no significant differences in IL-10-1082 A /G and -819 C/T allele frequency distribution between IBS and control group. The frequency of -819 T/T genotype in IBS group (51.1%)was significant more found than control (40.2%), which was also more seen from patients in three IBS subgroups. The IL-10-819 T allele frequency in both IBS with diarrhea (79.8%) and mixed IBS subgroup (77.1%) were distinct higher than controlled group (65.7%). The patients from IBS with diarrhea group had a greater frequency of -1082 A/A genotype compared with patients with mixed IBS, although there were no significant difference in -1082 A/A genotype between whole IBS group and controls. The combination of -1082 A/A and -819 T/T genotype in IL-10 promoter region was observed more frequent in IBS group than those in controlled group.Conclusion:The presence of IL-10-819 T/T genotype especially combination with -1082 A/A genotype maybe related to development of IBS.