title: Beta-trace protein in ascites and pleural effusions: limits of CSF leakage detection.
abstract: Rhino- and/or otoliquorrhea can be diagnosed by detecting beta-trace protein (β-TP) in nasal or ear secretions, as β-TP is found in high concentrations in cerebrospinal fluid (CSF) but not in serum. CSF fistulae following trauma or surgery can also occur at other anatomical sites, resulting in CSF leakage into the thoracic and abdominal cavities. By analogy, determination of ß-TP has also been used to diagnose CSF admixture in pleural effusions and ascites. However, no systematic study has yet evaluated the concentrations of β-TP in such fluids in the absence of CSF. To determine the validity of β-TP determination as a marker for the presence of CSF, we investigated β-TP concentrations in pleural effusions and ascites without CSF admixture. Patients from whom samples of ascites or pleural effusion and a paired plasma sample were available were investigated. One hundred sixty-four patients were prospectively recruited. ß-TP concentrations were determined by nephelometry. Mass spectrometric proteome analysis confirmed the presence of ß-TP in the samples. Median β-TP concentrations detected in ascites and pleural effusions (range, 0.014-26.5 mg/L, median 2.29 mg/L) exceeded the corresponding plasma concentrations 2.6-fold. According to cutoffs published to diagnose rhino- and otoliquorrhea, between 6.1% and 95.7% of the specimens would have been erroneously rated CSF-positive. Protein analysis confirmed the presence of β-TP in pleural effusion and ascites. Ascites and pleural effusion contain high concentrations of β-TP that exceed the levels in corresponding plasma. Therefore, β-TP is not a specific marker for the presence of CSF in these fluids.
authors.affiliation: Department of Neurology, University Greifswald, Greifswald, Germany.
authors.forename: Joanna
authors.initials: J
authors.lastname: Dietzel
authors.forename: Alexander
authors.initials: A
authors.lastname: Krebs
authors.forename: Dominique
authors.initials: D
authors.lastname: Böttcher
authors.forename: Manuela
authors.initials: M
authors.lastname: Sieb
authors.forename: Michael O
authors.initials: MO
authors.lastname: Glocker
authors.forename: Jan
authors.initials: J
authors.lastname: Lüdemann
authors.forename: Markus
authors.initials: M
authors.lastname: Roser
authors.forename: Alexander
authors.initials: A
authors.lastname: Dressel
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001201:Ascites / Q000378:metabolism*; D001930:Brain Injuries / Q000134:cerebrospinal fluid / Q000175:diagnosis; D002558:Cerebrospinal Fluid Otorrhea / Q000134:cerebrospinal fluid; D002559:Cerebrospinal Fluid Rhinorrhea / Q000134:cerebrospinal fluid; D016172:DNA Fingerprinting; D004591:Electrophoresis, Polyacrylamide Gel; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D019746:Intramolecular Oxidoreductases / Q000134:cerebrospinal fluid* / Q000378:metabolism; D054834:Lipocalins / Q000134:cerebrospinal fluid* / Q000378:metabolism; D008297:Male; D013058:Mass Spectrometry; D008875:Middle Aged; D010996:Pleural Effusion / Q000134:cerebrospinal fluid* / Q000378:metabolism; D020543:Proteome; D055815:Young Adult
chemical_list: D054834:Lipocalins; D020543:Proteome; D019746:Intramolecular Oxidoreductases; C022466:prostaglandin R2 D-isomerase