B-280 Sensitivity and Specificity of Beta-2 Transferrin Gel Electrophoresis With Immunofixation for Evaluating Nasal Cerebrospinal Fluid Leaks

Abstract Background Cerebrospinal fluid (CSF) rhinorrhea usually presents as unilateral clear thin nasal drainage, is caused by a direct communication from the subarachnoid space to sinonasal cavities and can lead intracranial infection, pneumocephalus, or death. Diagnosing CSF be challenging. While gold standard for leak confirmation surgical exploration, testing beta-2 transferrin (B2Tf) via agarose gel electrophoresis followed immunofixation (AGEI) remains initial non-invasive confirmatory test of choice. However, AGEI requires subjective interpretation immune-stained protein bands. Multiple studies have reported high sensitivity specificity B2Tf (90–100%), but other shown wider ranges 70–100%. Due small sample sizes methodologic differences between studies, comparing results problematic. The purpose this study was assess in confirming excluding patients with determine inter-reviewer variability interpretation. Methods This retrospective observational who had performed on their drainage 2020 through 2022. A pathologist four trained medical laboratory scientists conducted visual reviews archived gels were compared documented status. Results also original patients’ charts. Sensitivity specificity, agreement assessed rhinorrhea. exploration. included either negative exploration resolution after therapy aimed at treating rhinitis rhinosinusitis. varied five reviewers results, sensitivities ranging 65.0 86.0% (mean ± SD, 73.0 5.7) specificities 61.4 88.6% (84.1 11.0). false positive rate 8.7%, 13.9%. 57.1 82.1% 72.1, 9.3) 75.0 97.26% (91.6 9.4). abilities reliability identify moderate, kappa statistics 0.313 0.646 (weighted average 62.2, 4.0). Two demonstrated substantial almost perfect expert reviewer, two demonstrating moderate agreement. Conclusions lower than some previous reports, however larger size very well-defined clinical standards non-CSF present 9 14% cases, non-invasive, helpful stratifying into those more less likely There variability, highlighting challenges modality. Larger prospective would accurately diagnostic accuracy AGEI, well explore practices help limit variability.