The pathophysiology of febrile seizure (FS) is not fully understood, and research results have revealed a complex interaction of inflammation, genetic tendency and cytokines. Tumor necrosis factor alpha (TNF-α), interleukin 1 beta (IL-1β) and interleukin 6 (IL-6) are the main cytokines involved in the pathophysiology of FS. 1,2 MicroRNAs (miRNAs) are small non-coding RNAs, and their main target is messenger RNAs (mRNAs). More than two thousand miRNAs have been identified thus far, and more than half of these are expressed in the human brain. 3 Alteration in the expression levels of specific miRNAs has been suggested as a possible cause in the pathophysiology of different diseases, such as cancer, Parkinson disease and epilepsy. 3,4 miRNAs have emerged as potent regulators of inflammation. 4,5 For example, miRNA-146a is the first inflammation-associated miRNA.

Background Febrile seizure is the most common neurological disorder in childhood. The exact pathophysiology of febrile seizures is unknown. Recent studies showed the role of vitamin K in nonhematological and inflammatory disorders. This study aimed to investigate the serum vitamin K levels in children with febrile seizures. Aims To evaluate vitamin K levels in children with febrile seizures. Study Design Prospective case-control study. Methods This multicenter study examined representative populations in 8 different cities in Turkey between April 1, 2018 and April 1, 2019. Blood samples were taken from all children at presentation. Vitamin K1, vitamin K2, tumor necrosis factor-alpha, interleukin 1 beta, and interleukin 6 levels were determined by enzyme-linked immunosorbent assay. Results A total of 155 children were included in the study—84 children with febrile seizures and 71 children in febrile control group. Serum vitamin K1 and vitamin K2 levels were also higher in children with febrile seizures than in the controls. The results of statistical analysis showed that vitamin K1 and vitamin K2 levels were correlated with tumor necrosis factor-alpha, interleukin 1 beta, and interleukin 6 levels. The median vitamin K1 and vitamin K2 levels of children experiencing their first febrile seizure were higher than those in children with recurrent febrile seizures. Type of febrile seizure has no effect on serum vitamin K1 and vitamin K2 levels. Conclusion In children with febrile seizures, vitamin K levels are higher than those in the control group. These new findings may contribute to elucidating the etiopathogenesis of febrile seizures.