Abstract
Persistent measles virus infections play a crucial role in the pathomechanism of otosclerosis. The study was undertaken to investigate the role of tumor necrosis factor-α (TNF-α), interleukin 1β (IL-1β) and osteoprotegerin (OPG) in otosclerotic bone remodeling and to assess the relation of TNF-α, OPG and IL-1β expression levels in otosclerotic stape footplates to the occurrence of measles virus infection. 61 patients with otosclerosis were treated surgically. Thirty-one stapes obtained from cadavers of people, who had died from a sudden cause were used as a control group. The presence of measles virus RNA and the expression levels of TNF-α, IL-1β and OPG in otosclerotic foci were assessed using one-step RT-PCR. The presence of measles virus RNA was noted in 80.3 % of otosclerotic stapes (49 out of 61) and 9.7 % of normal tissues (3 out of 31). Transcript of TNF-α, IL-1β and OPG was detected in 40, 46 and 18 virus-positive stapes, respectively. The transcript level of TNF-α and IL-1β was significantly higher in otosclerotic tissues comparing to normal tissue. The OPG expression level was significantly lower in otosclerotic tissues comparing to controls. The presence of measles virus RNA in the stapes may indicate its role in the pathogenesis of otosclerosis. The presence of TNF-α and IL-1β mRNA in the virus-positive stapes could be the result of viral antigen stimulation and may be a marker of inflammation the otosclerotic focus. The lack of OPG mRNA and the presence of TNF-α and IL-1β mRNA in the majority of otosclerotic tissues reflect the bone remodeling process occurring in the stapes.