Utility of systemic immune-inflammation index, neutrophil-to-lymphocyte ratio, and platelet-to-lymphocyte ratio as a predictive biomarker in pediatric traumatic brain injury.

Background: Traumatic brain injury (TBI) remains the predominant cause of mortality and disability among the pediatric population. At present, there are no radiation-free, simple, and cost-effective tools available to assess the severity and prognosis of pediatric TBI. The systemic immune-inflammation index (SII), neutrophilto-lymphocyte ratio (NLR), and platelet-to-lymphocyte ratio (PLR) serve as inflammatory biomarkers that may assist in predicting the outcome of pediatric TBI. This research aims to assess the utility of SII, NLR, and PLR as a predictive biomarker in children with TBI.

Methods: A retrospective analysis was conducted on SII, NLR, and PLR by reviewing the medical records of all pediatric (age ≤18 years) TBI cases who came to the emergency department in the period from January 2023 to August 2024. Patients were categorized according to 28-day mortality and the severity of TBI. The correlation between the biomarkers and outcomes was analyzed.

Results: A total of 206 patients were included in this study. The mean age was 13.81 (1-18). The 28-day mortality rate was 5.3% (n = 11). There were no significant differences in SII, NLR, and PLR between the survivor and mortality groups (P = 0.317, P = 0.288, and P = 0.200, respectively). Based on the TBI severity, there was a significant difference in the SII, NLR, and PLR across mild, moderate, and severe TBI (P = 0.006, P = 0.002, P = 0.001, respectively).

Conclusion: The findings of our study did not reveal a significant predictive relationship between SII, NLR, and PLR to 28-day mortality. Nonetheless, there were significant differences in SII, NLR, and PLR among mild, moderate, and severe TBI groups. Further research under more controlled conditions is essential to facilitate the use of SII, NLR, and PLR as predictive biomarkers in pediatric TBI.