Association of Inflammatory and Nutritional Biomarkers in Children with Febrile Seizures: A Case-Control Study of NLR, PNI, and CAR.

Background/Objectives: Febrile seizures (FS) are the most frequent seizure disorder in childhood. Growing evidence suggests that systemic inflammatory responses may contribute to FS pathogenesis. Easily accessible inflammatory markers derived from routine blood tests, including the neutrophil-to-lymphocyte ratio (NLR), prognostic nutritional index (PNI), and C-reactive protein-to-albumin ratio (CAR), have been investigated as potential indicators of inflammatory status. This study aimed to explore the association between these biomarkers and FS in children. Methods: The medical records of 401 children were retrospectively evaluated, including 200 patients diagnosed with FS and 201 age-matched controls without a history of seizures. Demographic data and laboratory parameters were obtained, and NLR, PNI, and CAR were calculated. Group comparisons were performed using appropriate statistical tests. Multivariable logistic regression was applied to determine independent factors associated with FS, and receiver operating characteristic (ROC) analysis was conducted to evaluate biomarker performance. Results: Compared with controls, children with FS had higher neutrophil counts, NLR, and CAR values, whereas lymphocyte counts and PNI values were lower (all p < 0.05). Male sex was more frequent in the FS group (62.5% vs. 47.8%, p = 0.004). In multivariable analysis, younger age, male sex, and increased NLR were independently associated with FS. However, CAR and PNI did not remain significant after adjustment. NLR showed the highest discriminative ability among the evaluated markers, although its diagnostic performance was limited (AUC = 0.647). Conclusions: NLR may reflect the inflammatory response associated with febrile seizures and could provide supportive clinical information. However, its moderate diagnostic accuracy prevents its use as a standalone diagnostic marker. Further studies are required to clarify its clinical utility.