It’s not the future. It’s now.
So says, Dr. James Baumgartner, pediatric neurosurgeon at Florida Children’s Hospital with regard to the use of cord blood stem cells to treat a number of prevalent, devastating conditions in children. Dr. Baumgartner presented an update on a phase 1 trial using autologous (a child’s own) umbilical cord blood stem cells to treat acquired hearing loss in children.[i]
Families who elect to do cord blood banking ensure the availability of these stem cells for their family’s therapeutic use.
What is acquired hearing loss?
The term ‘childhood acquired hearing loss’ is defined as any hearing loss that is not present at birth, but identified at a later date. Approximately three children per 1,000 will be identified as having childhood acquired or late onset hearing loss.[ii]
Half of those cases are caused by genetics, and the other half are considered acquired (for example, as a result of prematurity, antibiotic exposure and/or recurrent ear infections.) The loss is often progressive for many children.
Hearing loss in a child is akin to a neurologic emergency. According to research presented by Dr. Baumgartner, approximately 12 months of normal auditory input is necessary before a child can speak. There is a limited time window during which the necessary brain development for language can occur. If a child is deprived of sound for 18 months, they will never speak normally. If a child is deprived of sound for more than 3.2 years, they will never acquire spoken language. “It’s a really big deal and a lot of people don’t realize that,” reflects Dr. Baumgartner.
What leads to it?
The organ of corti
, a sensitive element located in the inner ear, can be thought of as the body's microphone. It is situated on the basilar membrane in one of the three compartments of the Cochlea and contains four rows of hair cells which protrude from its surface.[iii]
Auditory nerve fibers rest below the hair cells and pass signals on to the brain.[iv]
Acquired hearing loss appears to be caused by a loss of hair cells in the organ of corti.
How can cord blood stem cells help
Current treatment options to address acquired loss in children include hearing aids or cochlear implants, which treats the symptom but does not cure the condition. Current trials are investigating ways to regenerate the lost hair cells in the organ of corti. There is hope regeneration can be induced or stem cells can be used to build up new hair cells.[v]
In a previous trial, infusing human umbilical cord blood stem cells to treat a murine model of hearing loss, the mice showed replacement of hair and support cells within the cochlea. “We thought this was meaningful,” reports Baumgartner.[vi]
The latest trial was further inspired by the results of a Duke University retrospective analysis of 30 patients treated with cord blood transplants to treat sensorineural hearing loss as a result of mucopolysaccharidosis.[vii]
(Mucopolysaccharidoses are a group of metabolic disorders.) The results of the transplants on hearing loss was measured in terms of ABR. ABR is a measure of the number of functioning hair cells. ABR improvement suggests an increase in the number of functioning hair cells.
“There was a pretty significant improvement,” says Baumgartner, in particular if the stem cell transplant was done before 25 months of age.” The Duke analysis suggests that this treatment did replace hair cells.
The current trial
Dr. Baumgartner is the lead investigator of this, Phase 1 clinical trial. The trial seeks to enroll 10 children between 6 weeks to 6 years of age with less than 18 months of hearing loss. The intended end point is spoken language. According to Dr. Baumgartner, improved ABR/audiogram alone is not enough.
Thus far, 9 patients have received IV infusions of their own cord blood stem cells (autologous) with no adverse events. The anticipated completion date is February, 2017. While Dr. Baumgartner is not allowed to discuss the results until the final patient is treated, “I can say the results from that Duke paper is something we are encouraged by.” When asked if donor cord blood might next be investigated, Dr. Baumgartner expressed that people are interested in using matched donor cord blood, but that “it’s easier to convince the FDA to use a 6 week’s old own cord blood because it’s considered safer.”
Cryo-Cell International will report on the results when the trial is complete. For parents, when weighing the pros and cons of cord blood banking, it’s incredible to hear that the number of conditions being treated with cord blood continues to steadily climb, as does the number of cord blood transplants (close to 35,000 to date.) When Cryo-Cell International began stem cell storage more than 25 years ago, acquired hearing loss was not one of the conditions that could be treated with cord blood stem cells. But today it is. It’s not the future, it’s now.
"Early Hearing Detection and Intervention Program." N.C. DPH: Early Hearing Detection and Intervention: Resources and Links
. NC Department of Health and Human Services, n.d. Web. 15 Mar. 2016.
Oghalai, John S. “Hearing and Hair Cells.” Department of Otolaryngology & Communicative Sciences, Baylor College of Medicine, 18 Dec. 1997. Web. 15 Mar. 2016.
Bodmer, Daniel. “Protection, Regeneration and Replacement of Hair Cells in the Cochlea: Implications for the Future Treatment of Sensorineural Hearing Loss.” Swiss Med Weekly
138. 47-48 (2008): n. pag. Web. 15 Mar. 2016.
Revoltella RP, et al., Cochlear Repair by Transplantation of Human Cord Blood CD133+ to Nod-Scid Mice Made Deaf with Kanamycin and Noise. Cell Transplantation 2008 17:665-678.
[vii] DaCosta et al, Improvements in Sensorineural Hearing Loss After Cord Blood Transplantation in Patients with Mucopolysaccharidosis. Arch Otalaryngol Head Neck Surg 2012 138(11)1071-1076.