Covid virus leaves antibodies that may attack healthy tissues: study

Such survivors with elevated levels of antibodies find themselves in a peculiar situation where these antibodies could attack their own organs and tissues, according to new findings of these studies. They also continue to carry such antibodies months after recovering from SARS-CoV-2 infection, it adds. 

A study carried out by the Cedars-Sinai Smidt Heart Institute in Los Angeles among 177 healthcare workers who had recovered from confirmed coronavirus infections contracted before the availability of vaccines, has found that all had persistent autoantibodies, including ones that can cause chronic inflammation and injury of the joints, skin and nervous system. 

"We would not normally expect to see such a diverse array of autoantibodies elevated in these individuals or stay elevated for as long six months after full clinical recovery," Susan Cheng who was part of the research team, said.

Patterns of elevated autoantibodies varied between men and women, the researchers reported in the Journal of Translational Medicine.

"We don't yet know how much longer, beyond six months, the antibodies will stay elevated and/or lead to any important clinical symptoms," Cheng said. "It will be essential to monitor individuals moving forward." 

The research team is investigating whether autoantibody elevations are linked with persistent symptoms in people with long SARS-CoV and the  autoantibody levels after infections with newer variants of the virus, including the Omicron variant.

Once the body learns to recognise SARS-CoV-2, either after infection or vaccination, the immune system's "memory B cells" generate fresh antibodies against the virus if there are not already enough antibodies circulating in the blood that can neutralise it. In a study reported on bioRxiv, researchers analysed the strength of more than 300 antibodies produced by memory B cells obtained from vaccinated volunteers, including some who had a prior SARS-CoV-2 infection.

"Omicron seemed to evade a very large share of the memory B cells pool," researchers said, adding, it "seems to still be efficiently recognised by 30 per cent of total antibodies and close to 10 per cent of all potent neutralising antibodies," said Matthieu Mahevas and Pascal Chappert of Universite de Paris in a joint email. Memory B cells' robust ability to proliferate and produce antibodies might compensate "in less than two days" for those antibodies' reduced effectiveness, they say.

Along with spike mutations that help the coronavirus break into cells, mutations that change how the virus behaves inside the cells are a big factor in why some variants have been more transmissible, researchers have discovered.