Polymorphisms of the TNF-α gene and risk of celiac disease in T1DM children

Background: Type 1 diabetes mellitus (T1DM) and celiac disease (CD) frequently occur together. Previous reports suggested that the (-308)A variant of the tumor necrosis factor-alpha (TNF-alpha) gene is associated either with T1DM or with CD. The aim of our study was to determine whether (-308)A and (-238)A allelic variants of the TNF-alpha gene might have any impact on the risk of CD in T1DM children. Methods: Three hundred and one T1DM children were enrolled to the study. The presence of CD was screened with IgA endomysial antibodies (EMA) test. Jejunal biopsy was performed to confirm CD. TNF-alpha -308 and -238 genetic variants were tested using the method of restriction fragment length polymorphism. Results: The prevalence of CD in the enrolled diabetic children was 6.3% (19 out of 301 children). The frequency of the (-308)A TNF-alpha variant was similar in the CD and the non-CD groups, exceeding the Hungarian healthy reference value. The number of (-238)A allele carriers was higher in the CD (4/19) than in the non-CD group (17/277) (p < 0.05). Conclusions Our study is limited by the small number of CD patients. On the basis of our findings, carriers of TNF (-308)A allele do not seem to have an increased risk for CD in T1DM. The association between TNF-alpha (-238)A allele carrier state and CD requires further investigation.