IL-10 and TGF-β1 gene polymorphisms in Greek patients with recurrent aphthous stomatitis

Recurrent aphthous stomatitis (RAS) is one of the most frequent inflammatory disorders of the oral mucosa. Cytokines, which play an important role in RAS pathogenesis, participate directly or indirectly in normal, immunological and inflammatory processes and are secreted from cells belonging to innate and adaptive immunity as a consequence of microbial and antigenic stimuli. Gene polymorphisms in specific cytokines may predispose to RAS development. The aim of this study was the investigation and association of IL-10 and TGF-β1 gene polymorphisms with RAS.

Study's cohort consisted of 60 Greek patients diagnosed with RAS, including 40 patients with minor, 10 patients with major and 10 with herpetiform aphthous ulcers. Forty age- and sex-matched control subjects were included in this study. DNA was extracted from whole blood samples of all patients and sequence-specific primers (SSP)-based polymerase chain reaction (PCR) was used for genotyping. Gene polymorphisms for cytokines IL-10 at loci -592 and -819 and for TGF-β1 at codon 10 were detected.

Significant differences between patients with minor RAS and healthy controls were recorded for IL-10 genotypes distribution at position -592 (p=0.042) and -819 (p=0.045) with predominance of C/A and C/T genotypes in RAS patients, respectively. Also, in patients with minor and herpetiform aphthous ulcerations, heterozygous TGF-β1 genotype C/T at codon 10 was associated with increased risk of RAS (p=0.044 and p=0.020, respectively).

These data provide evidence that genetic predisposition for RAS and possibly its specific clinical variants is related with the presence of gene polymorphisms for specific cytokines, including IL-10 and TGF-β1, which, in turn, may vary according to geographic origin and genetic background.