P-179 Assessment of Allelic and Genotypic Distribution of IL-6 and IL-10 Cytokine Genes in Ulcerative Colitis

Abstract

Ulcerative colitis (UC) is a form of inflammatory bowel disease (IBD) and is often confused with Irritable bowel Syndrome (IBS). Ulcerative colitis is treated as an autoimmune disease. A number of cytokines have been implicated in chronic inflammatory lesions of UC. It has been reported that inflammatory cytokines play important role in the development of the disease. The production of Il 10 presents important interindividual variations regulated by gene polymorphism within the promoter region. Studies have found that the inflamed mucosa from patients with UC revealed the increased expression and link between polymorphism of pro inflammatory cytokine IL 6. The aim of present study is to evaluate the role of cytokines IL-6 (174G/C) and IL-10 (1082G/A, -819C/T, -592C/A) gene polymorphism in UC and IBS patients. In this study we enrolled 56 patients of IBS, 36 patients of UC and 16 healthy controls (HC). Blood samples were obtained after informed consent for DNA isolation. PCR for IL 10 (-1082G/A, -819C/T, -592C/A) followed by restriction digestion using enzyme Mnl1, RsaI and MaeIII was done. For IL-6 (174G/C) PCR was done using ARMS PCR. Standard protocol has been followed for PCR and RFLP. The PCR products obtained were analysed on 2% agarose gel. Genotypic study of IL-10-1082G/A IBS, UC patients and HC showed dominance of AA genotype having 57.1%, 61.1% and 62% respectively. AG genotype was found 28.6% in IBS, 22.2% in UC and 12.5% in HC and GG genotype was found to be least in all the 3 groups having 14.3% in IBS, 16.7 in UC and 25% in HC. For IL-10-819 genotype maximum number of 50% of healthy controls followed by 39% of IBS showed CC genotype whereas 57% of UC patients had CT genotype. In genotype IL-10-592C/A majority of IBS (64.3%) followed by UC patients (44%) and HC (25%) showed AA genotype. Whereas IL-6 (174G/C) genotype was found to be 72.2% in UC and 69.64% in IBS patients and 75% in HC were GG genotype. Distribution of allelic frequency for IL10 (1082A/G), allele A was higher 71.43%, 75.0% and 68.75 in IBS, UC and HC respectively. In IL10 (819C/T) allele C was found to be higher in IBS (58.03%) and HC (62.5%) while T allele was higher in 61.12% in UC. In IL 10 (592C/A) allele A was higher in IBS (74.1%) and UC (63.88%) while allele C was higher in HC (56.25%). Whereas in IL 6 (174G/C) allele G was higher in all the study group having 83.33% in UC, 82.14% in IBS and 85.93% in HC. Results indicate AA genotype (low producer) of anti inflammatory cytokines IL-10 in patients with UC and IBS and A allele of IL 10 (592) showed significantly higher association. For IL-6 we found that the IBS and UC patients showed almost equal genotypic distribution and higher G allele frequency.