Nov 04, 2021 06:00:00

The new coronavirus can infect the ears and cause symptoms such as deafness

It has been

reported that some patients with Severe Acute Respiratory Syndrome (COVID-19) develop symptoms such as deafness, tinnitus, and dizziness. So far, the relationship between COVID-19 and ear symptoms has been unclear, but a new research team such as the Massachusetts Institute of Technology (MIT) has announced that the new coronavirus (SARS-CoV-2) has a sense of hearing and balance. It may infect the cells of the inner ear involved in the disease. '

Direct SARS-CoV-2 infection of the human inner ear may underlie COVID-19-associated audiovestibular dysfunction | Communications Medicine
https://www.nature.com/articles/s43856-021-00044-w

Study finds the SARS-CoV-2 virus can infect the inner ear | MIT News | Massachusetts Institute of Technology
https://news.mit.edu/2021/sars-cov-2-inner-ear-1029

Coronavirus May Infect, Harm the Inner Ear | Health News | US News
https://www.usnews.com/news/health-news/articles/2021-10-29/coronavirus-may-infect-harm-the-inner-ear

Even before the COVID-19 pandemic, it was known that cytomegalovirus and mumps virus, which causes mumps (mumps), could cause deafness. However, because it was difficult to obtain human inner ear tissue, it was difficult to proceed with research, and the mechanism was unclear.

So, the MIT Medical Engineering Institute belongs to Lee Gehrke of Mr. and Stanford University School of Medicine Konstantina Stankovic and his colleagues, had been engaged in the development of cell models for studying the infection of the inner ear from the previous pandemic of COVID-19 .. Under such circumstances, a pandemic of COVID-19 occurred, and Stankovic and his colleagues learned that some COVID-19 patients were experiencing symptoms such as deafness, tinnitus, and dizziness.

Since deafness and tinnitus are not very special symptoms, it was unclear whether COVID-19 was causally related to these symptoms. Therefore, the research team decided to study the possibility of SARS-CoV-2 infecting the inner ear using the cell model system of the inner ear that they had been working on for some time.

The newly developed cell model converts skin cells collected from humans into

iPS cells (induced pluripotent stem cells) and stimulates them into hair cells , sustentacular cells , nerve fibers, and Schwann cells found in the inner ear. Differentiated one. These cells were cultured as flat layers or three-dimensional organoids.

Using a cell model developed by the research team and samples of inner ear tissue obtained from patients who underwent surgery to remove tumors that cause severe dizziness and deafness, SARS-CoV-2 could infect inner ear cells. I investigated. As a result, hairy cells and Schwann cells express proteins such as ACE2 receptor and type II transmembrane serine protease necessary for SARS-CoV-2 invasion, so SARS-CoV-2 can be infected. It was confirmed that there was sex.

The hair cells examined by the research team were vestibular hair cells that sense the movement of the head and are involved in the sense of balance. On the other hand, cochlear hair cells related to hearing could not be studied in human cells because it is difficult to make them with a cell model, but proteins involved in SARS-CoV-2 invasion in mouse cochlear hair cells as well. Was shown to be expressed. In addition, an otoacoustic emission test conducted by the research team on patients who experienced mild to severe hearing loss after becoming COVID-19 showed that all 6 patients tested had damage to cochlear hair cells. The research team said that was suggested.

The results of this study show that SARS-CoV-2 can infect the inner ear and adversely affect hearing and balance. It is possible that some patients were diagnosed with COVID-19 but were distracted by other symptoms and did not notice hearing loss or tinnitus. It is unclear if tinnitus or dizziness will occur.

Gehrke believes that the inner ear model used in this study can be applied not only to SARS-CoV-2, but also to other virus studies. 'Having a model is the first step, and this study opens the door to combat not only SARS-CoV-2, but other viruses that affect hearing,' he said.