The absence of an association between Interleukin 1ß gene polymorphisms and recurrent aphthous stomatitis (RAS).

OBJECTIVES: Recurrent aphthous stomatitis (RAS) is a chronic, ulcerative disease with a probable polygenic mode of inheritance and complex etiology with a strong immunological background. The aim of the present study was to determine the possible association between two single nucleotide polymorphisms (SNPs) of the IL-1ß gene: IL-1ß-511 T>C (rs16944) and IL-1ß+3954C>T (rs1143634) and RAS susceptibility in a moderately large group of patients. DESIGN: One hundred and four patients with minor, major and herpetiform RAS and 75 healthy volunteers were genotyped at IL-1ß-511 T>C (rs16944) and IL-1ß+3954C>T (rs1143634) using the PCR-RFLP approach. The results were statistically analysed with chi-square test and test of difference between two rates of structure, with p<0.05 assumed to be a statistically significance level (Statistica 10, StatSoft®, Kraków, Poland). RESULTS: There were no statistically significant differences in the genotype distribution for the IL-1ß C[+3954]T polymorphism between the RAS and control groups. The frequency of IL-1ß*T[-511]/*T[-511] homozygotes among the patients was significantly higher when compared to our study control (p<0.0347). The results after stratification into carriers and non-carriers of C and T alleles did not clearly indicate which SNP may be considered a risk factor for RAS. CONCLUSIONS: The genetic association between the studied SNPs of the IL-1ß gene and RAS remains controversial and requires further investigation.

Clinical phenotype of recurrent aphthous stomatitis and interleukin-1ß genotype in a Polish cohort of patients.

BACKGROUND: The aim of this study was to evaluate the relation between a clinical profile and the interleukin-1ß (IL-1ß) genotype in a Polish cohort of patients with RAS. METHODS: One hundred and four patients with RAS were enrolled in the study and all were subject to an oral examination. The severity of RAS was assessed according to the clinical type of the disease, the number of lesions per flare-up and the length of intervals between the episodes. The genotyping of two SNPs of the IL-1ß gene, IL-1ß c.-511 T>C (rs16944) and IL-1ß c.+3954 C>T (rs1143634), was carried out by genomic DNA isolated from blood samples and by using the PCR-RFLP approach. The results were statistically analysed with chi-square and Fisher's tests and Spearman's rank correlation, with P < 0.05 assumed to be a significance level (Statistica 10; StatSoft® , Kraków, Poland). RESULTS: No statistically significant associations or correlations were found between the presence of *2 allele and minor, major or herpetiform RAS nor after the stratification using the RAS severity score and the classification based on the number of lesions per one flare-up. A weak correlation was found between the number of lesions per one flare-up and heterozygosity promoting the A type of RAS, characterized by a low number of eruptions. CONCLUSIONS: The presence of IL-1 ß *2 allele within the c.+3954 and c.-511 SNPs was found to be neither a significant risk factor for a higher incidence of any type of RAS, nor did it influence the disease severity and mode of recurrences.