β-trace protein test: new guidelines for the reliable diagnosis of cerebrospinal fluid fistula

Abstract

Objective Cerebrospinal fluid (CSF) fistulas need to be reliably diagnosed for the optimal management. Recently, in preference to β2-transferrin, another CSF protein, β-trace protein (βTP), is similarly used with a new method for CSF diagnosis. This study evaluates the sensitive interpretation and limits of this new βTP test for use in routine CSF fistula diagnosis. Methods Nephelometric detection of βTP has been made in nasal secretion, serum, and CSF samples from healthy individuals as well as patients with reduced glomerular filtration rate and with bacterial meningitis. Additionally, 53 patients with suspected CSF rhinorrhea are also analyzed. Results The βTP test can also be used to reliably diagnose CSF rhinorrhea even slightly better than the β2-transferrin test. It should not be used for patients with renal insufficiency and bacterial meningitis as they substantially increase serum and decrease CSF βTP values, respectively. Conclusion Quantitative measurement of βTP is a noninvasive, highly sensitive, quick, and inexpensive method that can be used for the detection of CSF rhinorrhea in nasal secretions. However, in cases where there is doubt about the interpretation, the results should be proved with β2-transferrin test or sodium-fluorescein test.