In the United States alone, hearing loss affects more than 48 million people.
More than 12% of the global population is affected by some degrees of hearing loss, even if they’re otherwise completely healthy, so imagine how amazing this news is when this discovery came to light!
Researchers at the University of Indiana, School of Medicine has identified the autophagy pathway in hair cells that is connected to permanent hearing loss caused by the aminoglycosides class of antibiotics.
The aminoglycoside class of antibiotics consists of many different agents. In the United States, gentamicin, tobramycin, amikacin, plazomicin, streptomycin, neomycin, and paromomycin are approved by the US Food and Drug Administration (FDA) and are available for clinical use. Of these, gentamicin, tobramycin, and amikacin are the most frequently prescribed by intramuscular or intravenous injection for systemic treatment.
According to Sick Kid’s Hospital, children who already experience any loss of balance or hearing should take extra caution when being treated with Aminoglycosides. Some side effects that are not common, but are recorded, include the loss of hearing, ringing or buzzing in the ear, or a feeling of “fullness”, in addition to loss of balance and dizziness.
How widespread is this ‘uncommon problem’, exactly?
For more than a century, infections have been treated via the administration of Aminoglycosides. With its low cost and low incidence of antibiotic resistance, it’s been one of the most recommended, first-line-of-response treatment for many mild to serious bacterial infections.
However, data shows that Aminoglycosides has been one of the causes of hair cell death in the ear, which is one of the ways your body translates sound vibration and reception, and thus resulting in a causal and subsequent permanent hearing loss in 20 to 47% of patients who has been administered Aminoglycosides. To put that in perspective? If you flipped a coin and it landed on heads, you’ve got permanent hearing loss.
What’s the culprit behind hearing loss caused by aminoglycosides?
“As aminoglycosides specifically trigger a rapid localization change of RIPOR2 in hair cells, we hypothesize that RIPOR2 is essential for aminoglycoside-induced hair cell death,” Zhao said. Dr. Zhao is one of the key researchers in this project.
The researchers developed a model simulation with significantly decreased RIPOR2 expression. Through these experiments, Zhao’s team discovers that the simulation had no significant hair cell death, and no hearing loss after treatment with aminoglycosides class antibiotics.
“We then discovered RIPOR2 regulates the autophagy pathway in hair cells. Knowing this, we developed other laboratory models without the expression of several key autophagy proteins that did not exhibit hair cell death or hearing loss when treated with the antibiotic,” said Jinan Li, Ph.D.
The study suggests that a new line of medication can be developed based on the identified proteins and prevent aminoglycosides-induced hearing loss in the future.
If you’ve experienced any degree of hearing loss during or after an illness or infection, it’s best to speak with your hearing specialist or family doctor to determine whether it’s a temporary loss of hearing. In cases where the hearing loss is permanent, there are ways to treat it and elevate your quality of life once again. Hearing loss is not the end, and we have tools to help you.