Nerve growth factor serum level is reduced in patients with sensorineural hearing impairment: possible clinical implications

Nerve growth factor (NGF) is the first and best characterised member of a family of neurotrophic factor. NGF is produced by numerous cells and it is present in physiologically relevant amounts in the bloodstream. It is known to promote the survival of peripheral sensory neurons and can be potentially useful as a therapeutic agent in neuronal system. On the both these observations we based our hypothesis that low circulating NGF might lead to sensorineural hearing loss (SNHL). To address this question we measured the levels of NGF in the bloodstream of patients affected by SNHL. The results showed that the amount of circulating NGF in these patients is significantly lower compared to levels found in patients not affected by this deficit. The results of the present study demonstrated that NGF might be a useful candidate for preventing the damage and promoting recovery or degeneration of the auditory pathways in humans.