Interleukin-4 and Interleukin-4 Receptor Alpha Gene Polymorphisms in Recurrent Aphthous Stomatitis.

Area of Science:

• Immunogenetics
• Oral Medicine
• Molecular Biology

Background:

• Recurrent aphthous stomatitis (RAS) significantly impacts quality of life.
• RAS pathogenesis is linked to T helper-1 (Th1) cytokine overexpression.
• Interleukin-4 (IL-4) and its receptor (IL-4Rα) counteract Th1 pathways, suggesting their gene polymorphisms may influence RAS.

Purpose of the Study:

• To investigate the association between IL-4 and IL-4Rα gene polymorphisms and the susceptibility to minor RAS.
• To determine if specific single-nucleotide polymorphisms (SNPs) or haplotypes in IL-4 and IL-4Rα genes are more prevalent in RAS patients compared to healthy controls.

Main Methods:

• Genotyping of 3 IL-4 promoter SNPs (-1098G/T, -590C/T, -33C/T) and 1 IL-4Rα SNP (+1902 A/G) in 64 minor RAS patients and 141 healthy controls.
• Analysis of allele frequencies, genotype distributions, and haplotype associations between the patient and control groups.

Main Results:

• No significant differences in IL-4 allele frequencies or IL-4Rα gene polymorphism between groups.
• RAS patients showed a higher frequency of the IL-4 -590 CC genotype and a lower frequency of the IL-4 -590 TC genotype.
• Specific IL-4 haplotypes (TCT, GTT, GCT, GTC) were more frequent in RAS patients, while GCC and TTT haplotypes were more common in controls.

Conclusions:

• Specific polymorphisms and haplotypes within the IL-4 gene are associated with an increased predisposition to recurrent aphthous stomatitis.
• IL-4 gene variations may play a role in the pathogenesis of RAS.
• IL-4Rα gene polymorphism does not appear to be significantly associated with RAS susceptibility.