Cochlear Changes Caused by Peginterferon α-2b.

To evaluate the effect of peginterferon α-2b on guinea pigs' hearing and its cochlea, and to determine whether these effects are permanent or reversible. This study is an experimental animal study done on the organs of Corti of 30 guinea pigs after a peginterferon α-2b injection course. The cochleae of guinea pigs were extracted and examined by scanning electron microscopy for the right side and immunohistochemistry for the left side. All guinea pigs were subjected to pinna reflex, otological examination, and distortion product otoacoustic emission (DPOAE) both before and after the receiving of interferon (IFN). Electron microscopic scanning and immunohistochemistry of the cochleae revealed that peginterferon α-2b has a harmful effect on guinea pigs' cochleae, in the form of structural changes in the hair cells and supporting cells with apoptotic changes in the organ of Corti and the stria vascularis. These changes were reversible. DPOAE showed a significant reduction in distortion product mean amplitude and signal-to-noise ratio in all frequencies after 3 days from the last dose of IFN injection except at 1,006 Hz. After 14 days, there was a significant improvement in most of the frequencies, but are still below the normal values.