Background: Perilymphatic fistula (PLF), defined as an abnormal communication between the inner and middle ear, presents with a symptomatology of hearing loss and vestibular disorder that is indistinguishable from a number of other inner ear diseases. Methods of diagnosis remain controversial. We have previously shown that Cochlin-tomoprotein (CTP) is selectively detected in the perilymph. To establish a definite diagnostic test for PLF using CTP as a biochemical marker, we examined the diagnostic performance of the CTP detection test. Methods: CTP detection test was performed by Western blot using recombinant human CTP (rhCTP) as a spiked standard. We evaluated the specificity of the CTP detection test by testing non-PLF cases. To describe the limitations of the test, we tested samples from patients with middle ear infection. We also studied the stability of CTP protein by storing the samples at room temperature (25°C) or 4°C for 55 days. The effects of repeated freezing and thawing were also evaluated. Serially diluted perilymph was tested to find out the detection limit of CTP. Findings: We have established a standardized CTP detection test using high (0.27 ng) and low (0.13 ng) spiked standards of rhCTP in Western blotting. Middle ear lavages (MEL) from 54 of 55 non-PLF cases were negative in the CTP detection test, i.e. the specificity of the test is 98.2%. MEL from 43 out of 46 cases with chronic suppurative otitis media or middle ear cholesteatoma were negative for CTP. CTP is a stable protein and detection was not affected by the storage, or freezing and thawing. The detection limit of perilymph was 0.161 µl/lane in an average of 5 samples. Interpretation: CTP is a stable perilymph-specific protein, and this CTP detection could be the first clinically established diagnostic tool to detect PLF with a high specificity. PLF is surgically correctable by sealing the fistula. Appropriate recognition and treatment of PLF can improve hearing and balance in afflicted patients.

Keywords:
Diagnostic accuracy, Perilymphatic fistula, Hearing loss, Vertigo, Perilymph, COCH gene, Cochlin isoform, Cochlin tomoprotein, Human, Specificity
1.
Abe S, Katagiri T, Saito-Hisaminato A, Usami S, Inoue Y, Tsunoda T, Nakamura Y: Identification of CRYM as a candidate responsible for nonsyndromic deafness, through cDNA microarray analysis of human cochlear and vestibular tissue. Am J Hum Genet 2003;72:73–82.
2.
Black FO, Pesznecker S, Norton T, Fowler L, Lilly DJ, Shupert C, Hemenway WG, Peterka RJ, Jacobson ES: Surgical management of perilymphatic fistulas: a Portland experience. Am J Otol 1992;13:254–262.
3.
Fitzgerald DC: Perilymphatic fistula and Meniere’s disease: clinical series and literature review. Ann Otol Rhinol Laryngol 2001;110:430–436.
4.
Friedland DR, Wackym PA: A critical appraisal of spontaneous perilymphatic fistulas of the inner ear. Am J Otol 1999;20:261–276.
5.
Goodhill V: Sudden deafness and round window rupture. Laryngoscope 1971;81:1462–1474.
6.
House JW, Morris MS, Kramer SJ, Shasky GL, Coggan BB, Putter JS: Perilymphatic fistula: surgical experience in the United States. Otolaryngol Head Neck Surg 1991;105:51–61.
7.
Hughes GB, Sismanis A, House JW: Is there consensus in perilymph fistula management? Otolaryngol Head Neck Surg 1990;102:111–117.
8.
Ikezono T, Omori A, Ichinose S, Pawankar R, Watanabe A, Yagi T: Identification of the protein product of the Coch gene – hereditary deafness gene – as the major component of bovine inner ear protein. Biochim Biophys Acta 2001;3:258–265.
9.
Ikezono T, Shindo S, Ishizaki M, Li L, Tomiyama S, Takumida M, Pawankar R, Watanabe A, Saito A, Yagi T: Expression of cochlin in the vestibular organ of rats. ORL J Otorhinolaryngol Relat Spec 2005;67:252–258.
10.
Ikezono T, Shindo S, Li L, Omori A, Ichinose S, Watanabe A, Kobayashi T, Pawankar R, Yagi T: Identification of a novel Cochlin isoform in the perilymph: insights to Cochlin function and the pathogenesis of DFNA9. Biochem Biophys Res Commun 2004;314:440–446.
11.
Ikezono T, Shindo S, Sekiguchi S, Charuk Hanprasertpong, Li L, Pawankar R, Morizane T, Baba S, Koizumi Y, Sekine K, Watanabe A, Komatsuzaki A, Murakami S, Kobayashi T, Miura M, Yagi T: Cochlin-tomoprotein (CTP), a novel perilymph-specific protein and a potential marker for the diagnosis of perilymphatic fistula. Audiol Neurootol 2009;14:338–344.
12.
Kohut RI, Hinojosa R, Budetti JA: Perilymphatic fistula: a histopathologic study. Ann Otol Rhinol Laryngol 1986;95:466–471.
13.
Li L, Ikezono T, Watanabe A, Shindo S, Pawankar R, Yagi T: Expression of full-length Cochlin p63s is inner ear specific. Auris Nasus Larynx 2005;32:219–223.
14.
Minor LB: Labyrinthine fistulae: pathobiology and management. Curr Opin Otolaryngol Head Neck Surg 2003;11:340–346.
15.
Nomura Y: Perilymph fistula: concept, diagnosis and management. Acta Otolaryngol Suppl 1994;514:52–54.
16.
Podoshin L, Fradis M, Ben-David J, Berger SI, Feiglin H: Perilymphatic fistula: the value of diagnostic tests. J Laryngol Otol 1994;108:560–563.
17.
Robertson NG, Khetarpal U, Gutierrez-Espeleta GA, Bieber FR, Morton CC: Isolation of novel and known genes from a human fetal cochlear cDNA library using subtractive hybridization and differential screening. Genomics 1994;23:42–50.
18.
Robertson NG, Lu L, Heller S, Merchant SN, Eavey RD, McKenna M, Nadol JB, Miyamoto RT, Linthicum FH, Lubianca Neto JF, Hudspeth AJ, Seidman CE, Morton CC, Seidman JG: Mutations in a novel cochlear gene cause DFNA9, a human nonsyndromic deafness with vestibular dysfunction. Nat Genet 1998;20:299–303.
19.
Robertson NG, Cremers CW, Huygen PL, Ikezono T, Krastins B, Kremer H, Kuo SF, Liberman MC, Merchant SN, Miller CE, Nadol JB, Sarracino DA, Verhagen WI, Morton CC: Cochlin immunostaining of inner ear pathologic deposits and proteomic analysis in DFNA9 deafness and vestibular dysfunction. Hum Mol Genet 2006;15:1071–1085.
20.
Schuknecht HF: Myths in neurotology. Am J Otol 1992;13:124–126.
21.
Sekine K, Ikezono T, Matsumura T, Shindo S, Watanabe A, Li L, Pawankar R, Nishino T, Yagi T: Expression of cochlin mRNA splice variants in the inner ear. Audiol Neurotol 2010;15:88–96.
22.
Shindo S, Ikezono T, Ishizaki M, Sekiguchi S, Mizuta K, Li L, Takumida M, Pawankar R, Yagi T: Spatiotemporal expression of Cochlin in the inner ear of rats during postnatal development. Neurosci Lett 2008;444:148–152.
23.
Wall C, Rauch SD: Perilymph fistula pathophysiology. Otolaryngol Head Neck Surg 1995;112:145–153.
24.
Weber PC, Bluestone CD, Perez B: Outcome of hearing and vertigo after surgery for congenital perilymphatic fistula in children. Am J Otolaryngol 2003;24:138–142.
© 2009 S. Karger AG, Basel
2009
Copyright / Drug Dosage / Disclaimer
Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher.
Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in government regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug.
Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.
You do not currently have access to this content.