TBICheck: a rapid test to rule-out CT scans in mild Traumatic Brain Injury patients

Introduction The TBICheck TM Rapid test is an immunochromatographic rapid test capable of assisting in the triage of patients with mild Traumatic Brain Injury (mTBI) suspected of brain lesions. It quantitatively determines heart-type Fatty Acid Binding Protein (H-FABP) levels in whole blood, serum, or plasma. The aim of the present study was to evaluate its technical performance and test it in two different cohorts of mTBI patients as a potential diagnostic tool for detecting brain lesions in patients with mTBI. Material and methods Description of the assay: Linearity and low limit of quantification (LLOQ) of TBICheck TM lateral flow assay were determined using serial dilution of standardized samples. Results were read using the TBICheck TM Reader, a mobile photometric immunoassay analyzer based on reflectance measurements to capture the optical density. Obtained results were compared to classical ELISA assays, Meso Scale Diagnostics (MSD). Patient cohorts: Two different cohorts of adult mTBI patients were included: a retrospective one including 82 patients and a prospective one including 65 patients. Values of H-FABP area under the curve (AUC), specificity (SP), sensitivity (SE) and negative predictive value (NPV) were calculated. Results The H-FABP dose response fitted a linear regression within the range of 0.5-25 ng/mL. LLOQ in blood was 0.5 ng/mL. High Spearman correlation was found (ρ=0.933, p<0.001) when MSD ELISA and TBICheck TM concentrations were compared. In the retrospective cohort, when the clinical sensitivity was set at 100%, a specificity value of 32.9% was obtained. In the prospective cohort, the SP value raised to 66.1% with 100% SE, meaning that 6 out of 10 patients might be discharged on the basis of their serum H-FABP concentration at hospital admission. Conclusions The quantification of H-FABP by using the TBICheck TM Rapid test on adult mTBI patients may allow to rule out the need of a CT-scan reducing the radiation exposure and avoiding the long waiting times in emergency units. It may lead to savings in hospital resources and assists medical doctors to provide the most appropriate treatment to the patients.