Massachusetts Eye and Ear Infirmary

COVID is a real pain in the ear

/ Kevin McCormack / 6 Comments

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The more you learn about COVID-19 the more there is to dislike about it. The global death toll from the virus is now more than five million and for those who survive there can be long-term health consequences. We know COVID can attack the lungs, heart and brain. Now we are learning it can also mess up your ears causing hearing problems, ringing in the ear (tinnitus) and leave you dizzy.

Viral infections are a known cause of hearing loss and other kinds of infection. That’s why, before the pandemic started, Dr. Konstantina Stantovic at Massachusetts Eye and Ear and Dr. Lee Gherke at MIT had been studying how and why things like measles, mumps and hepatitis affected people’s hearing. After COVID hit they heard reports of patients experiencing sudden hearing loss and other problems, so they decided to take a closer look.

They took cells from ten patients who had all experienced some hearing or ear-related problems after testing positive for COVID and, using the iPSC method, turned those cells into the kind found in the inner ear including hair cells, supporting cells, nerve fibers, and Schwann cells.  

They then compared those to cells from patients who had similar hearing issues but who had not been infected with COVID. They found that the hair and Schwann cells both had proteins the virus can use to infect cells. That’s important because hair cells help with balance and the Schwann cells play a protective role for neuronal axons, which help different nerve cells in the brain communicate with each other.

In contrast, some of the other cells in the inner ear didn’t have those proteins and so were protected from COVID.

In a news release Dr. Stankovic says it’s not known how many people infected with COVID experienced hearing issues. “Initially this was because routine testing was not readily available for patients who were diagnosed with COVID, and also, when patients were having more life-threatening complications, they weren’t paying much attention to whether their hearing was reduced or whether they had tinnitus. We still don’t know what the incidence is, but our findings really call for increased attention to audio vestibular symptoms in people with Covid exposure.”

The doctors are not sure how the virus gets into the inner ear but speculate that it may enter through the Eustachian tube, that’s a small passageway that connects your throat to your middle ear. When you sneeze, swallow, or yawn, your Eustachian tubes open, preventing air pressure and fluid from building up inside your ear. They think that might allow particles from the nose to spread to the ear.

The study is published in the journal Communications Medicine.

CIRM has funded 17 different projects targeting COVID-19, several of which are still active.

Listen up! Stem cell scientists craft new ears using children’s own cells

/ Kevin McCormack / 6 Comments

Imagine growing up without an ear, or with one that was stunted and deformed. It would likely have an impact on almost every part of your life, not just your hearing. But now scientists in China say they have found a way to help give children born with this condition a new ear, one that is grown using their own cells.

Microtia is a rare condition where children are born with a deformed or underdeveloped outer ear. This is what it can look like.

Microtia ear

In an interview in New Scientist, Dr. Tessa Hadlock, at Massachusetts Eye and Ear Infirmary in Boston, said:

“Children with the condition often feel self-conscious and are picked on, and are unable to wear glasses.”

In the past repairing it required several cosmetic surgeries that had to be repeated as the child grew. But now Chinese scientists say they have helped five children born with microtia grown their own ears.

In the study, published in the journal EBioMedicine, the researchers explained how they used a CT scan of the child’s normal ear to create a 3D mold, using biodegradable material. They took cartilage cells from the child’s ear, grew them in the lab, and then used them to fill in tiny holes in the ear mold. Over the course of 12 weeks the cells continued to multiply and grow and slowly replaced the biodegradable material in the mold.

While the new “ear” was being prepared in the lab, the scientists used a mechanical device to slowly expand the skin on the child’s affected ear. After 12 weeks there was enough expanded skin for the scientists to take the engineered ear, surgically implant it on the child’s head, and cover it with skin.

Over the course of the next two and a half years the engineered ear took on a more and more “natural” appearance. The children did undergo minor surgeries, to remove scar tissue, but other than that the engineered ear shows no signs of complications or of being rejected.

Here is a photo montage showing the pre and post-surgical pictures of a six-year old girl, the first person treated in the study.

Microtia

Other scientists, in the US and UK, are already working on using stem cells taken from the patient’s fat tissue, that are then re-engineered to become ear cells.

Surgeons, like Dr. Hadlock, say this study proves the concept is sound and can make a dramatic difference in the lives of children.

“It’s a very exciting approach. They’ve shown that it is possible to get close to restoring the ear structure.”