Association of cell adhesion molecule gene polymorphisms with recurrent aphthous stomatitis

Recurrent aphthous stomatitis (RAS) is a common oral ulcerative condition. At ulcer sites vascular adhesion molecule-1 (VCAM-1), E-selectin and intercellular adhesion molecule-1 (ICAM-1) are strongly expressed on blood vessels, and ICAM-1 is expressed on keratinocytes. Expression of these molecules would promote leukocyte accumulation and invasion of the epithelium. Thus, polymorphisms in these candidate genes might contribute to RAS susceptibility. We investigated whether the inheritance of specific selectin, ICAM and VCAM gene polymorphisms is associated with RAS susceptibility.

Ninety-six RAS cases and 153 controls were recruited from a Jordanian population. Blood was collected for hematological investigations and genotyping. Six SNPs were genotyped: E-selectin rs5361 and rs1805193, L-selectin, rs2205849, ICAM-1 rs5498, ICAM-5 rs885743 and VCAM-1 rs1800821. Association was determined using chi-square and binary logistic regression analysis after correcting for confounding factors. Linkage disequilibrium was determined using the EH program, and the Phase 2.1 program was used to construct and compare haplotypes between cases and controls.

There was a significant association of the A allele (Pcorr  = 0.027), AA and AC genotypes (OR = 10.9 and 9.0, respectively) of the E-selectin rs5361 gene polymorphism and TAA haplotype (rs2205849, rs5361, and rs1805193, respectively; P = 0.03) with RAS. None of the other SNPs showed a significant association.

This is the first report to link inheritance of the A allele, AA and AC genotypes of the E-selectin rs5361 polymorphism with increased risk of RAS. Further studies in different patient cohorts are needed to confirm the association, and functional analyses might clarify the biological significance of the association.