Red Cell Distribution Width to Platelet Count Ratio as a Promising Indicator of Mortality for Acute Traumatic Brain Injury: a Study on Large ICU Cohorts

Abstract

Background: Outcome prediction is crucial for the effective treatment of patients with acute traumatic brain injury (TBI). However, there is still a lack of reliable and routinely available blood predictors with sufficient clinical evidence till now. This research is designed to investigate the association between red cell distribution width to platelet count ratio (RPR) and mortality risk of TBI patients, thereby providing a promising indicator for prognosis evaluation of TBI.Methods: Clinical data of 2,220 patients with TBI that extracted from two large ICU cohorts (MIMIC-III database and eICU Collaborative Research Database), were integratively analyzed using our developed method named MeDICS. The association between RPR and hospital mortality was determined using the logistic regression model and Lowess Smoothing technique. Multivariable logistic regression analyses were used to control for confounders. The receiver-operating characteristic (ROC) curve was depicted to show the prognostic performance. The stepwise backward elimination method was performed to develop a nomogram, where tenfold cross-validation was used to protect it against overfitting. Results: Higher RPR can be observed among non-survivors than survivors with TBI (p < 0.001). Besides, high RPR was associated with increased mortality, with the odds ratio (OR) increasing from RPR of 0.074-0.098 (OR: 2.13, 95% CI 1.39 to 3.28, p = 0.001) to > 0.098 (OR: 3.82, 95% CI 2.55 to 5.72, p < 0.001), using RPR of < 0.057 as the reference. RPR had a moderately good prognostic performance with an area under ROC Curve (AUC) of 0.7367, which was greater than that of Glasgow Coma Scale (GCS, AUC = 0.6022). The nomogram consisting of RPR, GCS and other risk factors can further improve the prognostic value of RPR (Harrell’s C-index = 0.8582, p value of Hosmer-Lemeshow test = 0.3159). In addition, in-vivo experiments indicated that the continuous change in RPR after TBI was attributed to the development of inflammatory response.Conclusions: As an easily accessible index, RPR is a promising predictor of mortality for acute TBI. The nomogram generated from RPR can be used in resource-limited settings, thus be proposed as a prognosis evaluation aid for patients with TBI in all levels of medical system.

Prediction of Early Mortality Among Children With Moderate or Severe Traumatic Brain Injury Based on a Nomogram Integrating Radiological and Inflammation-Based Biomarkers

“…On the other hand, along with their well-known hemostatic functions, platelets play an active role in inflammation regulation. While platelets bind to coagulation factors, they also include a large variety of inflammatory factors, such as TNF-α, interleukins, and serotonin, all of which are involved in tissue injury and repair ( 7 ). Therefore, it is reasonable to conclude that a high PLR may be associated with an increased risk of death in pediatric patients with MS-TBI.…”

“…Additionally, complete blood counts are frequently performed as non-invasive laboratory procedures in clinical practice. Peripheral blood counts, including neutrophil, lymphocyte, and platelet counts, have previously been used to assess central nervous system and peripheral inflammation following injury ( 7 ). Recently, several inflammation-based prognostic scores, including the neutrophil-to-lymphocyte ratio (NLR) ( 8 ), platelet-to-lymphocyte ratio (PLR) ( 9 ), lymphocyte-to-monocyte ratio (LMR) ( 10 ) and systemic immune-inflammation index (SII) ( 11 ) have been demonstrated to accurately predict outcomes in patients with neurological diseases such as stroke, subarachnoid hemorrhage (SAH), and Alzheimer's disease ( 12 – 14 ).…”