The Impact of Neutrophil-Lymphocyte Ratio in Febrile Seizures: A Systematic Review and Meta-Analysis.

This meta-analysis was conducted to determine the relationship between neutrophil to lymphocyte ratio (NLR) and febrile seizure (FS). Our study was registered with the PROSPERO (ID: CRD42021259944). Web of Science, Embase, PubMed, Scopus, and ProQuest Central were searched, and finally, 17 studies were included. Standardized mean difference (SMD) was reported with a 95% confidence interval (CI) for the NLR levels. Compared with the febrile control group, the FS patients' NLR levels were significantly higher (SMD = 0.49; 95%CI = 0.26 to 0.72, P < 0.001). Furthermore, we conducted a comparison of NLR levels between febrile controls against simple and complex FS cases separately and found that NLR levels of children with either simple or complex FS were higher compared with those of febrile controls (SMD = 0.42, 95%CI = 0.14 to 0.69, P = 0.003 and SMD = 0.90, 95%CI = 0.71 to 1.09, P < 0.001, respectively). Also, in comparison with the NLR levels of the simple FS group, the complex FS patients' NLR levels were significantly higher (SMD = 0.59, 95%CI = 0.34 to 0.85, P < 0.001). Our study indicated that NLR could be recommended as an inexpensive diagnostic biomarker for FS. In addition, it can be useful when distinguishing between simple FS and complex FS.