IL-10 and TNF-alpha polymorphisms in subjects with irritable bowel syndrome in Mexico.

BACKGROUND: there has been recent evidence of an alteration in irritable bowel syndrome (IBS) immune regulation, as well as variations in cytokine polymorphisms.

AIMS: to determine the frequency of the IL-10 (-1082G/A) and TNF-alpha (-308G/A) polymorphisms in subjects with IBS in Mexico.

METHODS: volunteers answered the Rome II Questionnaire and were classified as IBS (n = 45) and controls (n = 92). The IBS subjects were then categorized as IBS-D: 22.2%, IBS-C: 28.9%, and IBS-A/M: 48.9%. The polymorphism frequency among groups was compared.

RESULTS: there were no differences between IBS vs. controls in the frequency of the high (8.9 vs. 18.5%), intermediate (60.0 vs. 57.6%), or low (23.9 vs. 38.9%) producer IL-10 genotypes, p = 0.315. Neither were there differences in the high (0 vs. 1.1%), intermediate (55.4 vs. 43.2%), or low (43.5 vs. 56.8%) producer TNF-alpha genotypes, p = 0.296. However the low producer of IL-10 was more frequent in IBS-D vs. IBS-C vs. IBS-A/M (63.6 vs. 7.1 vs. 33,3%) p = 0.023.

CONCLUSIONS: in this group of volunteers in Mexico, the frequency of the IL-10 (-1082G/A) and TNF-alpha (-308G/A) genotypes was similar in IBS and controls. However, there was a greater frequency of the low producer of IL-10 in those subjects with IBS-D, suggesting a genetic predisposition to abnormal immune regulation due to a lower anti-inflammatory component in this subgroup.