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

Objective: Cerebrospinal fluid (CSF) fistulas need to be reliably diagnosed for the optimal management. Recently, in preference to beta2-transferrin, another CSF protein, beta-trace protein (betaTP), is similarly used with a new method for CSF diagnosis. This study evaluates the sensitive interpretation and limits of this new betaTP test for use in routine CSF fistula diagnosis.
Methods: Nephelometric detection of betaTP 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 betaTP test can also be used to reliably diagnose CSF rhinorrhea even slightly better than the beta2-transferrin test. It should not be used for patients with renal insufficiency and bacterial meningitis as they substantially increase serum and decrease CSF betaTP values, respectively.
Conclusion: Quantitative measurement of betaTP 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 beta2-transferrin test or sodium-fluorescein test.