Association of IL‐1Ra gene polymorphism, but no association of IL‐1β and IL‐4 gene polymorphisms, with Kawasaki disease

The purpose of this study was to evaluate whether IL-1 beta (IL-1beta promoter and IL-1beta exon 5), IL-1 receptor antagonist (IL-1 Ra), and IL-4 (IL-4 promoter and IL-4 intron 3) gene polymorphisms act as markers of susceptibility to Kawasaki disease (KD), or of the severity of the disease. The study included 107 KD patients and 103 normal controls. Polymorphisms for cytokine genes were detected by polymerase chain reaction (PCR). Genotypes and allelic frequencies for cytokine gene polymorphisms in both groups were compared. No significant difference was observed in the genotypes and allelic frequencies of cytokines between patients with coronary aneurysm and without. In addition, there was no significant association in the genotype and allelic frequencies of IL-1 beta, IL-4, and IL-6 in patients with KD. The genotype I/II for IL1-Ra and the frequency of allele II for IL1-Ra are associated with a higher susceptibility to KD, and thus may be useful markers for predicting the development of KD.