Histologic otosclerosis is associated with the presence of measles virus in the stapes footplate.
OBJECTIVE
Persistent measles virus infection of the otic capsule is presumed to be one of the etiologic factors in otosclerosis. The viral pathogenesis of otosclerosis could be established only by correlative analysis: histologic examination of the stapes footplates and reverse-transcriptase polymerase chain reaction amplification of the viral RNA. At present, histologic analysis of the removed stapes footplates is the only appropriate method of distinguishing otosclerotic and nonotosclerotic stapes fixations.


BACKGROUND
The presence of measles virus was shown in otosclerotic patients by reverse-transcriptase polymerase chain reaction amplification of the viral RNA and detecting the viral proteins by immunohistochemistry.


METHODS
Nucleic acids (mRNA, vRNA, and DNA) were extracted from ankylotic stapes footplates of stapes fixation patients (n = 44). Measles virus genomic nucleoprotein RNA was amplified by seminested reverse-transcriptase polymerase chain reaction. Amplification results were correlated to postoperative histologic findings.


RESULTS
Measles virus RNA was detectable only in histologically otosclerotic stapes footplates (n = 32). Histology for virus-negative footplates (n = 12) excluded otosclerosis. Virus-negative stapes footplates showed annular calcification (n = 8), bone resorption with increased numbers of hemosiderophages (n = 2), and mononuclear cell infiltration with osteolysis (n = 2).


CONCLUSIONS
Stapes ankylosis is a heterogenous disease causing conductive hearing loss with different causes. Nonotosclerotic stapes fixations may belong to degenerative disorders with variable histopathology. Otosclerosis is an inflammatory disease resulting from persisting measles virus infection of the otic capsule.
Karosi
Tamás
T
Departments of Otolaryngology Head & Neck Surgery, University Medical School of Debrecen, Debrecen, Hungary.
Kónya
József
J
Petkó
Mihály
M
Sziklai
István
I
D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D008459:Measles virus / Q000648:ultrastructure*; D008875:Middle Aged; D009698:Nucleoproteins / Q000032:analysis; D010040:Otosclerosis / Q000473:pathology / Q000601:surgery / Q000821:virology*; D012367:RNA, Viral / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013199:Stapes / Q000473:pathology / Q000821:virology*; D013201:Stapes Surgery
D009698:Nucleoproteins; D012367:RNA, Viral