Neutrophil to lymphocyte ratio in the prediction of coagulopathy in traumatic brain injury

Lay abstract Traumatic brain injury (TBI) is a public health issue of increasing incidence. Coagulopathy after TBI is a frequent event, associated with a poor prognosis and biomarkers that could predict coagulopathy occurrence are needed. The neutrophil-to-lymphocyte ratio (NLR) is useful as a cost-effective biomarker to assess prognosis and the need for cranial computed tomography in patients with mild TBI. We found that NLR could additionally predict which TBI patients might develop coagulopathy with a 87.5% sensitivity and 52.9% specificity. Combination of NLR with other low-cost biomarkers and the clinical findings might further increase accuracy in the prediction of coagulopathy. Aim: Traumatic brain injury (TBI) is a public health issue of increasing incidence. Coagulopathy after TBI is a frequent event, associated with a poor prognosis, and biomarkers that could predict coagulopathy occurrence are needed. The neutrophil-to-lymphocyte ratio (NLR) is useful as a cost-effective biomarker to assess prognosis and the need for cranial computed tomography in patients with mild TBI. As no study has yet evaluated the association of NLR with coagulopathy, we investigated whether the NLR at presentation could predict coagulopathy occurrence after TBI. Materials & methods: A retrospective study was conducted of patients aged >18 years who attended the emergency department (ED) with TBI, over a 3-year period. We included all patients for whom the NLR at presentation was available, and who underwent a brain CT scan. Results: The study included 173 patients (mean age 57.4 +/- 21.1 years) with TBI, the most frequent cause of which was a fall. According to the Glasgow Coma Scale, 37 patients had severe TBI, 19 moderate and 117 mild TBI and 40 patients (23.1%) developed coagulopathy. Their mean NLR was 7.5 +/- 6.7. Using receiver operating characteristic curve analysis, a cut-off value of 4.2 for NLR had 87.5% sensitivity and 52.9% specificity for predicting coagulopathy occurrence. Conclusion: Coagulopathy occurs frequently after TBI. This study investigated the value of NLR as a biomarker to predict coagulopathy occurrence, and concluded that NLR might be a novel and inexpensive biomarker for decision making in the management of TBI. Combination of NLR with other low-cost biomarkers and the clinical findings might further increase accuracy in the prediction of coagulopathy.