Association Analysis of Interleukin-1β, Interleukin-6, and HMGB1 Variants with Postictal Serum Cytokine Levels in Children with Febrile Seizure and Generalized Epilepsy with Febrile Seizure Plus

BACKGROUND AND PURPOSEFebrile seizure (FS) is a unique type of seizure that only occurs during childhood. Genelized epilepsy with febrile seizure plus (GEFS+) is a familial epilepsy syndrome associated with FS and afebrile seizure (AFS). Both seizure types are related to fever, but whether genetic susceptibility to inflammation is implicated in them is still unclear. To analyze the associations between postictal serum cytokine levels and genetic variants in the cytokine genes interleukin (IL)-1β, IL-6, and high mobility group box-1 (HMGB1) in FS and GEFS+. METHODSGenotyping was performed in 208 subjects (57 patients with FS, 43 patients with GEFS+, and 108 controls) with the SNaPshot assay for IL-1β-31 (rs1143627), IL-1β-511 (rs16944), IL-6-572 (rs1800796), and HMGB1 3814 (rs2249825). Serum IL-1β, IL-6, and HMGB1 levels were analyzed within 2 hours after seizure attacks using the ELISA in only 68 patients (38 FS, 10 GEFS+, and 20 controls). The allele distribution, genotype distribution, and correlations with serum cytokine levels were analyzed. RESULTSNear-complete linkage disequilibrium exists between IL-1β-31 and IL-1β-511 variants. CT genotypes of these variants were associated with significantly higher postictal serum IL-1β levels than were CC+TT genotypes in FS (both p