Contribution of the interleukin 4 gene to susceptibility to subacute sclerosing panencephalitis

Background: Although the exact pathogenesis of subacute sclerosing panencephalitis (SSPE) remains to be determined, both viral and host factors seem to be involved. Objective: To identify host genetic factors involved in the development of SSPE. Methods: We investigated the association of polymorphisms in the T helper (Th)1 and Th2 cytokine, and related genes (interferon [IFN]-gamma, IFN-gamma receptor 1 [IFN-gammaR1], IFN-gammaR2 [IRF-1], interleukin 12 receptor beta1 [IL-12Rbeta1], IL-4, IL-4R, and IL-10 genes) with SSPE in Japanese subjects. Results: A significant association (P = .03) was observed between SSPE and the T allele of the biallelic polymorphism at position -589 in the promoter region of the IL-4 gene. The IRF-1 allele 1 tended to interact with the IL-4 promoter -589 T genotype in the development of SSPE (P = .06), as judged on logistic regression analysis. The frequency of the genotype combination of IL-4 promoter -589 T and IRF-1 allele 1 (at least 1 allele) in patients with SSPE was much higher than that in the controls (47.7% vs 22.0%; P = .003, chi(2) analysis). However, there was no association between other polymorphisms and SSPE. Conclusion: To our knowledge, this study is the first to demonstrate the possibility that the IL-4 promoter gene -589 T gene polymorphism with increased IL-4 synthesis in combination with IRF-1 allele 1 confers host genetic susceptibility to SSPE in Japanese subjects.