Interleukin-18 and IL18-607A/C and-137G/C Gene Polymorphisms in Patients with Penicillin Allergy

This study investigated the association between polymorphisms (-607A/C and -137G/C) in the promoter region of the IL18 gene (which encodes interleukin 18) and serum levels of IL-18, using standard genotyping techniques (sequence specific primer-polymerase chain reaction) and an enzyme-linked immunosorbent assay, respectively, in patients allergic to penicillin. A higher frequency of A alleles and the AA genotype was found at position -607A/C in patients allergic to penicillin than in control subjects. For the -137G/C position, the C allele was more frequent in patients allergic to penicillin than in control subjects. Haplotype analysis showed that the -607A/-137C haplotype was more frequent in patients allergic to penicillin than in control subjects. The patients had a significantly higher serum IL-18 level than the control subjects. In conclusion, IL18 -607A/C and -137G/C promoter polymorphisms are associated with susceptibility to penicillin allergy. In particular, the -137G/C position appears to play an important role in IL18 expression.