Diagnostic Accuracy of Beta-2 Transferrin GEL Electrophoresis for Detecting Cerebrospinal Fluid Rhinorrhea
Recommended Citation
Eide J, Mason W, Mackie H, Cook B, Ray A, Asmaro K, Robin A, Rock J, Craig J. Diagnostic Accuracy of Beta-2 Transferrin GEL Electrophoresis for Detecting Cerebrospinal Fluid Rhinorrhea. Journal of Neurological Surgery, Part B: Skull Base 2024; 85.
Document Type
Conference Proceeding
Publication Date
2-5-2024
Publication Title
Journal of Neurological Surgery, Part B: Skull Base
Abstract
Background: Unilateral thin clear rhinorrhea (UTCR) is a common presenting rhinologic complaint and may represent a variety of pathologies, the most concerning being cerebrospinal fluid (CSF) rhinorrhea. Assessing for beta-2 transferrin (B2Tf) on gel electrophoresis (GE) has become the preferred initial noninvasive testing modality for confirming CSF rhinorrhea due to reportedly high sensitivity (87-100%) and specificity (71-100%). However, despite widespread use, there have been relatively few studies assessing its diagnostic accuracy. The purpose of this single-institution study was to determine the accuracy of B2Tf GE in detecting CSF rhinorrhea. Methods: A single-center retrospective review was conducted from 2015 and 2021 for all patients who presented with UTCR and underwent B2Tf GE. Institutional review board approval was obtained for this study. The gold standard for diagnostic confirmation of true and false positives (TP, FP) as well as false negatives (FN) was endoscopic exploration. The gold standard for true negative (TN) was response to medical therapy. A true positive was defined as a positive B2Tf GE result with positive endoscopic exploration and repair. Indeterminate B2Tf GE results were recorded but not included in analyses. Results: A total of 72 patients underwent 100 B2Tf GE tests. Of these, 35 patients (48.6%) were diagnosed with CSF rhinorrhea. Of the 100 B2Tf GE tests, there were 42 TPs, 40 TNs, 12 FPs, and 6 FNs yielding 87.5% sensitivity, 76.9% specificity, 77.8% positive predictive value, and 87% negative predictive value. Conclusion: While this single-institutional data demonstrates sensitivities, specificities, and predictive values within ranges previously reported in the literature, it also demonstrates potential diagnostic limitations. Clinicians should be aware that FP and FN results can occur. On a case-by-case basis, especially if B2Tf GE results deviate from clinical suspicion, one must consider the utility of repeat B2Tf GE versus other forms of confirmatory diagnostic testing. Future studies should explore reasons for erroneous B2Tf GE results and how these may change clinical decision-making.
Volume
85
