Do gene polymorphism in IL-1β, TNF-α and IL-6 influence therapeutic response in patients with drug refractory epilepsy?

SummaryPurposePro-inflammatory cytokines may play an important pathophysiological role in patients with epilepsy. To understand the role of genes encoding pro-inflammatory cytokines in epilepsy, this study aimed to evaluate the polymorphisms of the promoter regions of IL-1β-511C > T (rs16944), TNF-α–308G > A (rs1800629) and IL-6-174G > C (rs1800795) genes and to look into the interaction between these genes in influencing seizure susceptibility, seizure frequency and response to therapy.MethodsThe comparative frequency of polymorphism was determined in rs16944, rs1800629 and rs1800795 using PCR-RFLP in a group of 120 persons with epilepsy (PWE) and 110 ethnically matched healthy subjects of comparable age and sex in the North Indian population.ResultsAlleles and genotypes of rs16944, rs1800629 and rs1800795 were not found to influence the odds ratio of having susceptibility to epilepsy. Also gene–gene interaction of possible nine combinations of these genes did not show any positive association with epilepsy. The genotype and allelic frequency of rs1800795 showed a significant association (p < 0.05) in seizure frequency (number of seizures/6-months) and drug refractory epilepsy. However, the genotype and allelic frequency of rs16944 and rs1800629 were not found to have such effect.ConclusionThis study demonstrates that the rs16944, rs1800629 and rs1800795 polymorphism does not act as a strong susceptibility factor for epilepsy in North Indian population. The genotypic association of rs1800795 with seizure frequency and drug-refractory epilepsy raises the issue that a specific set of polymorphic genes can influence seizures and therapeutic response in epilepsy.