S100B protein level for the detection of clinically significant intracranial haemorrhage in patients with mild traumatic brain injury: a subanalysis of a prospective cohort study

Abstract

BackgroundClinical assessment of patients with mild traumatic brain injury (mTBI) is challenging and overuse of head CT in the ED is a major problem. Several studies have attempted to reduce unnecessary head CTs following a mTBI by identifying new tools aiming to predict intracranial bleeding. Higher levels of S100B protein have been associated with intracranial haemorrhage following a mTBI in previous literature. The main objective of this study is to assess whether plasma S100B protein level is associated with clinically significant brain injury and could be used to reduce the number of head CT post-mTBI.MethodsStudy design: secondary analysis of a prospective multicentre cohort study conducted between 2013 and 2016 in five Canadian EDs. Inclusion criteria: non-hospitalised patients with mTBI with a GCS score of 13–15 in the ED and a blood sample drawn within 24 hours after the injury. Data collected: sociodemographic and clinical data were collected in the ED. S100B protein was analysed using ELISA. All CT scans were reviewed by a radiologist blinded to the biomarker results. Main outcome: the presence of clinically important brain injury.Results476 patients were included. Mean age was 41±18 years old and 150 (31.5%) were women. Twenty-four (5.0%) patients had a clinically significant intracranial haemorrhage. Thirteen patients (2.7%) presented a non-clinically significant brain injury. A total of 37 (7.8%) brain injured patients were included in our study. S100B median value (Q1–Q3) was: 0.043 µg/L (0.008–0.080) for patients with clinically important brain injury versus 0.039 µg/L (0.023–0.059) for patients without clinically important brain injury. Sensitivity and specificity of the S100B protein level, if used alone to detect clinically important brain injury, were 16.7% (95% CI 4.7% to 37.4%) and 88.5% (95% CI 85.2% to 91.3%), respectively.ConclusionPlasma S100B protein level was not associated with clinically significant intracranial lesion in patients with mTBI.

S100B, GFAP, UCH-L1 and NSE as predictors of abnormalities on CT imaging following mild traumatic brain injury: a systematic review and meta-analysis of diagnostic test accuracy

“…Another issue with S100B interpretation is its temporal serum kinetics, having a short half-life ranging from 60 to 120 h [89]. The importance of this is underscored by the findings of Blais-Lecuyer et al [11]. Despite the use of the conventional 0.10 μg/L threshold, in their study the sensitivity-specificity relationship appeared to be inverted with a relatively high false negative rate.…”

“…Limiting inclusion to studies sampling within 6 h resulted in the exclusion of 10 studies. Four were excluded as biomarker sampling was performed more than 6 h following injury [11,29,50,70], and 5 were removed as this was either not reported [8,51,69], or reported as a mean rather than a maximal time to sampling [9,49]. We also excluded a study using a matched-control design, which may induce a high risk of bias from this and all further analyses [16].…”

“…Next, we limited inclusion to studies using the Roche assays. This resulted in the exclusion of nine studies [10,11,14,15,29,36,50,51,70], with 20 remaining included. The optimal cutoff in this model was substantially lower at 0.39 μg/L, which had a sensitivity of 75% (95%CI 44-92) and a specificity of 72% (95%CI 57-84) with an AUC of 80% (95%CI 57-84).…”

“…One study [11] appeared to be a particular outlier, which is likely the result of their use of a 24-h time window to presentation from injury followed by a further 24-h potential time window to biomarker sampling. This likely contributed to a higher false negative rate, given the short half-life of S100B [75].…”

The Potential of S100 Calcium-Binding Protein B and Glial Fibrillary Acid Protein in Predicting the Intracranial Lesions in Mild Traumatic Brain Injury: A Systematic Review of Literature

“…No randomized control studies were identified. A pediatric sample was used in four studies [21], [22], [23], [24], and a sample older than 16 years was used in ten studies [25], [26], [27], [28], [29], [30], [31], [32], [33], [34]. A skier was utilized as a test subject in one research.…”