Beta-trace protein (prostaglandin D synthase)--a stable and reliable protein in perilymph.

OBJECTIVE: Beta-trace protein (beta-TP) has been analysed in human cerebrospinal fluid (CSF) and other body fluids. Beta-trace protein is a very sensitive and specific clinical marker and can confirm reliably the presence of CSF in patients with a suspected CSF leakage. DESIGN: Perilymph specimens from the scala vestibuli (n=10) and from the lateral semicircular canal (n=4) were taken from patients undergoing stapedotomy or surgery for acoustic neuroma. During post-mortem examinations perilymph specimens from the scala vestibuli (n=70), the scala tympani (n=11), endolymph specimens (n=21) and CSF specimens (n=17) were obtained. All specimens were analyzed by a one-dimensional immunoelectrophoresis using a polyclonal, monospecific antibody. RESULTS: Specimens from live surgery showed a mean concentration of 51.5 +/- 48.9 mg/l beta-TP in scala vestibuli perilymph. Specimens from post-mortem examinations revealed a mean concentration of 49.1 +/- 17.7 mg/l in CSF, 71.9 +/- 29.3 mg/l in perilymph and 68.0 +/- 21.7 mg/l in endolymph. There was no evidence of a circadian alteration of beta-TP in CSF or inner ear fluids. CONCLUSIONS: Our results demonstrated clearly that beta-TP is contained in human perilymph and endolymph. This is the first published data that point out the aptitude of the beta-TP-test in verifying traces of perilymph, a valuable diagnostic tool for the existence of perilymphatic leaks.

[Diagnosis and surgical treatment of liquorrhea]. / Diagnostikk og kirurgisk behandling av likvoré.

BACKGROUND: Liquorrhea caused by cerebrospinal fluid fistula may lead to meningitis and should be treated surgically. The diagnostic approach and the surgery may be difficult and improvements are needed. MATERIAL AND METHODS: We present two cases of liquorrhea. A review of the diagnostic and surgical methods is given. RESULTS: In both cases the diagnosis was confirmed by detection of beta-trace protein. In one case the surgery was complicated. This patient had a cerebrospinal fluid fistula from the sphenoid sinus. In a third operation, performed with sodium fluorescein dying, the fistula was closed. INTERPRETATION: Rhinorrhea and meningitis are unspecific signs of a possible cerebrospinal fluid fistula. Beta-trace protein is recommended as a diagnostic marker, because this protein has the highest positive predictive value for the presence of cerebrospinal fluid. High-resolution CT scans are the most helpful imaging technique for determining the leakage site, but this is not conclusive in all cases. Using sodium fluorescein may give better outcomes of surgical interventions.

Incidence of occult cerebrospinal fluid fistula during paranasal sinus surgery.

OBJECTIVE: To determine the incidence of occult cerebrospinal fluid fistulas after endoscopic paranasal sinus surgery. DESIGN: Prospective diagnostic test study with a 6-month follow-up in case of cerebrospinal fluid detection. SETTING: Tertiary care hospital. SUBJECTS: The study population comprised 69 patients undergoing routine endoscopic paranasal sinus surgery. Patients with an obvious intraoperative or postoperative cerebrospinal fluid fistula were not included. INTERVENTION: Analysis of 112 samples from intraoperative applied tamponades and of 69 serum samples using a nephelometric research assay for beta-trace protein (prostaglandin D synthase). MAIN OUTCOME MEASURES: Incidence of occult cerebrospinal fluid fistula during endoscopic paranasal sinus surgery as indicated with the help of a test for beta-trace protein; at least a 6-month follow-up of patients with an occult cerebrospinal fluid fistula; and relation of occult cerebrospinal fluid fistula with surgical experience of the surgeon. RESULTS: Beta-trace protein was found in ethmoid roof samples from 2 patients, giving an incidence of 2.9% for occult cerebrospinal fluid fistula. Both patients were operated on by very experienced surgeons. Signs of a cerebrospinal fluid fistula were not found at follow-up at least 6 months after surgery. CONCLUSIONS: Nephelometric beta-trace protein assay is a highly sensitive method to detect otherwise unobserved cerebrospinal fluid fistulas. The clinical course of the 2 patients with an occult cerebrospinal fluid fistula indicated the possibility of an uneventful follow-up of patients with small fistulas.

Predictive values of beta-trace protein (prostaglandin D synthase) by use of laser-nephelometry assay for the identification of cerebrospinal fluid.

OBJECTIVE: beta-Trace protein (beta-TP) is an immunological marker for the detection of cerebrospinal fluid traces. The aim of the study was to evaluate the predictive values of a new research assay for beta-TP. METHODS: A total of 154 specimens from patients with otorrhea or rhinorrhea were investigated for cerebrospinal fluid (CSF) by use of a laser-nephelometric assay for beta-TP. Samples were obtained between January 1994 and November 2000. A sample was reported to be positive for CSF when the beta-TP concentration was more than 6 mg/L. Case evaluations were performed retrospectively and tabulated for indication, clinical course, additional investigations, surgical procedure, and follow-up. RESULTS: beta-TP was detected in 16 specimens; 138 samples were negative for beta-TP with a value less than 3 mg/L. One sample was suggestive of CSF traces at 4.6 mg/L. In correlation with the clinical course, the intraoperative findings, intraoperative visualization with sodium fluorescein, high-resolution computed tomography of the paranasal sinuses or the petrous bone, computed tomographic cisternography, magnetic resonance imaging, and radionuclide cisternography, there was no false-positive result. On four occasions, false-negative results occurred, with an overall accuracy of 0.974. The beta-TP test had a negative predictive value of 0.971 and a positive predictive value of 1. CONCLUSION: Analysis of betas-TP via the nephelometric assay is a valuable and reliable test in cranial base surgery for the identification of CSF.