Lack of association between the IL13 variant Arg110Gln and susceptibility to cedar pollinosis in a Japanese population.

BACKGROUND: Interleukin (IL)-13 has come to be appreciated as a molecule critically involved in allergic inflammatory responses. Recent studies revealed that a common variant in the coding region of the IL13 gene, Arg110Gln, has been implicated in the development of asthma and atopy. METHODS: To assess whether the IL13 variant Arg110Gln is associated with cedar pollinosis, one of the most common atopic diseases in the Japanese population, we examined the Arg110Gln variant using PCR-RFLP to compare the genotype and allele frequencies between 95 patients with cedar pollinosis and 95 healthy control subjects. Relationships between the Arg110Gln variant and the pollinosis-related traits, e.g. rhinitis severity, eosinophil counts in nasal secretion and serum total and allergen-specific IgE levels, were also investigated. RESULTS: The frequencies of the minor allele Gln110 were 25.8% in patients with cedar pollinosis and 30.9% in healthy control subjects (p > 0.05). There was also no significant difference in the genotype frequencies between cases and controls (p > 0.05). In addition, we found no significant association of the Arg110Gln variant with any of the pollinosis-related phenotypes (p > 0.05). CONCLUSIONS: Our data suggest lack of evidence for identifying the variant Arg110Glnat the IL13 locus as a genetic risk factor involved in the development of Japanese cedar pollinosis.