Hearing Loss Image

A study investigating stem cell therapy for hearing loss is currently recruiting participants at Florida Hospital for Children and the Florida Hospital Center for Cellular Therapy. The aim of this clinical trial is to discover whether an infusion of autologous human umbilical cord blood cells is a safe and effective treatment for children who have acquired hearing loss.

Hearing loss affects up to an estimated 300 million people worldwide, with incidence increasing with age. Due to a life time of exposure to environmental toxins, excessive noise, and in some cases, a genetic predisposition, the incidence of hearing loss increases from 1 in 1000 at birth, to 1 in 3 by the age of 80. This degeneration in hearing occurs due to the death of inner ear hair cells and sensory neurons, which do not re-generate.

Sound perception occurs in the inner ear, beginning with the sensory hair cells that are found in the cochlea. These hair cells convert the vibration of sound into electrical signals. The electrical signals are passed on through the neurons and the auditory nerve to the brain. Sensorineural hearing loss describes the loss of ability to convert sound signals into electrical signals and the transferring of these signals to the brain. There is currently no cure for sensorineural hearing loss.

There have been some advances in the use of stem cells to generate hair cells and auditory neurons in an effort to treat hearing loss. Recent laboratory studies have been successful at differentiating stem cells into hair cells, and have even implanted stem cells in the inner ear of laboratory animals. Experiments using human umbilical cord blood treatment of mice and guinea pigs with acquired hearing loss have demonstrated re-growth of hair cells, and some restoration of auditory brainstem response.

Umbilical cord blood stem cells are derived from the umbilical cord of a newborn baby. This blood has a high concentration of stem cells. To date, umbilical cord blood stem cells have been used to treat multiple diseases, including leukemia, lymphoma, and anemia.

Participants included in the stem cell therapy for hearing loss study will be between 6 weeks and 6 years old, with sensorineural hearing loss (unilateral or bilateral, sudden or progressive, moderate to profound). Participants will only be included if they have a normally shaped cochlea, acquired hearing loss, with a negative genetic test. Additionally, participants will only be included if they were fit with hearing aids no later than 6 months after diagnosis, and have less than 18 months of hearing loss at the time of treatment. Patients will not be included if there is evidence of genetic component to the hearing loss, if the patient has been fitted with a cochlear implant, if the hearing loss is mild, or if it has been longer than 18 months since the hearing loss was diagnosed.

The participants will receive a single dose of intravenously administered autologous human umbilical cord cells. The cells will be obtained from the patients’ umbilical cord stem cells that were collected at birth and stored at the Cord Blood Registry. The primary outcomes for the study are safety, feasibility, improvement of inner ear function, audition and language development.

 

Clinicaltrials.gov “Safety of Autologous Stem Cell Infusion for Children With Acquired Hearing Loss” Available from: http://www.clinicaltrials.gov/ct2/show/NCT02038972?term=stem+cells+AND+hearing&rank=1Last Accessed: July 23, 2014.

Gwenaëlle S. G. Géléoc, Jeffrey R. Holt “Sound Strategies for Hearing Restoration”Science 9 May 2014:Vol. 344 no. 6184, DOI: 10.1126/science.1241062

Francisco Santaolalla, Carlos Salvador, AgustínMartínez, Jose María Sánchez, Ana Sánchez del Rey“Inner ear hair cell regeneration (A look from the past to the future)”Neural Regeneration ResearchVol. 8 no.24, p2284-2289, 2013.

Image courtesy of rajcreationzs / FreeDigitalPhotos.net

 

Written by Deborah Tallarigo, PhD

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