A recent study from MIT and Massachusetts Eye and Ear examined patients with Covid-19 who reported symptoms of hearing loss, tinnitus, vertigo and balance problems after infection.
The study provides evidence that the virus can infect inner ear cells, particularly hair cells.
The researchers conducted the study on 10 Covid-19 patients who reported a variety of ear-related symptoms, with the most prominent symptom being hearing loss.
Each individual’s hearing loss varies from mild to profound; nine of the patients had tinnitus and six patients had vertigo.
Using elderly inner ear tissue from patient donors who had surgery to treat severe vertigo and did not have Covid-19, as well as self-developed new cell models of the inner ear, they were able to conduct the study and share their findings .
They found an infection pattern seen in human inner ear tissue that matched the patient’s symptoms.
Because it is very difficult to harvest human tissue from the inner ear, the team developed models to be used for further research. They were able to create tissue models of the inner ear by taking cells from human skin, reprogramming the cells to become stem cells, and then directing the stem cells to develop into hair cell precursors, or Schwann cells.
Anatomy of the ear.
The study was co-led by Dr. Lee Gehrke and Dr. Konstantina Stankovic. Gehrke is the Hermann LF von Helmholtz Professor at MIT’s Institute of Medical Engineering and Science. Stankovic is a former associate professor at Harvard Medical School and former chief of otology and neurotology at Massachusetts Eye and Ear, who is now the Bertarelli Foundation Professor and chair of the Department of Otolaryngology – Head and Neck Surgery at Stanford University School of Medicine.
Minjin Jeong, the lead author of the paper, which appeared in Communications Medicine on October 29, 2021, is a former postdoctoral fellow in Stankovich’s lab at Harvard Medical School and is now a postdoctoral fellow at Stanford Medical School.
Healthy and damaged hair cells in the cochlea.
Findings
For an individual to be infected with SARS-CoV-2, they must have specific proteins on their cell surfaces.
The researchers found the proteins in both types of human inner ear cell samples: hair cells and Schwann cells. Hair cells function to sense sound waves for hearing and movement to maintain balance, while Schwann cells provide electrical insulation for nerve cells in the inner ear.
Like the inner ear samples collected from donors, the same cell precursors produced by the researchers have the proteins required for SARS-CoV-2 infection. The virus mainly infects the hair cell precursors. Schwann cells are less affected.
The results of the experiments strongly suggest that SARS-CoV-2 can infect the inner ear and cause hearing and balance problems associated with Covid-19, although the overall percentage of patients with Covid-19 who had problems related to ears, not known.
Health and good physical and mental condition
Add Comment