Heat shock protein gene 70-2 polymorphism is differentially associated with the clinical phenotypes of ulcerative colitis and Crohn's disease

Background and Aim: A single nucleotide polymorphism in heat shock protein 70‐2 (HSP70‐2) has been shown to be associated with a severe clinical course in Crohn's disease (CD), but it is not known if such a relationship exists in ulcerative colitis (UC). The aim of the present study was to identify associations between the HSP70‐2 polymorphism and the clinical courses of CD and UC in Koreans. Methods: Restriction fragment length polymorphism analysis was performed for HSP70‐2 polymorphisms using the PstI‐cleavage site present in the B allele but not in the A allele of the DNA obtained from 101 patients with CD, 144 patients with UC, and 245 age‐ and sex‐matched healthy controls. Study subjects were classified by disease behavior, severity and extent of disease. Results: In CD, multivariate analysis showed that the AA genotype of HSP70‐2 polymorphisms was associated with non‐perforating disease (OR 10.10, 95% CI 1.66–15.38) and male sex (OR 3.56, 95% CI 1.04–12.23), and that the BB genotype was associated with severe CD (OR 12.03, 95% CI 1.60–101.56). In contrast, multivariate analysis for UC showed that the AA genotype was associated with severe UC (OR 2.02, 95% CI 1.34–3.03). Conclusions: CD patients with BB genotype of HSP70‐2 polymorphism tend to experience a more severe clinical course and allele A is associated with more severe UC. HSP70‐2 polymorphism may be used to predict CD and UC phenotypes, which can illuminate immunological differences in CD and UC.