Severe COVID-19 Cases Linked to Antibodies That Attack the Body

In people infected by COVID-19, some life-threatening cases are traced to weak spots in patients' immune systems, revealed analyses reported in two papers in the journal Science. The new study discovered some root causes of life-threatening COVID-19, says study leader Jean-Laurent Casanova, a Howard Hughes Medical Institute Investigator at The Rockefeller University. “These two papers provide the first explanation for why COVID-19 can be so severe in some people, while most others infected by the same virus are okay,” he says. Casanova’s team first began enrolling COVID-19 patients in their study in February. They sought young people with severe forms of COVID-19 to investigate whether these patients might have underlying weaknesses in their immune systems that made them especially vulnerable to coronavirus.

The study planned to scan patients’ genomes, particularly a set of 13 genes involved in interferon immunity against influenza. In healthy individuals, interferon molecules act as the body’s security system.

Interferons detect invading viruses and bacteria and sound the alarm, bringing other immune defenders to the scene. The team found that 23 out of 659 patients studied carried errors in genes involved in producing antiviral interferons.

Study Findings

• 3.5 percent of the study patients with severe coronavirus had mutations in genes involved in antiviral defense.
• 10 percent of patients with severe COVID-19 disease created “auto-antibodies” that attack the immune system, instead of fighting the virus.
• 94 percent of patients with harmful antibodies were men.

“It’s an unprecedented finding,” says study co-author Isabelle Meyts, a pediatrician at the University Hospitals KU Leuven, in Belgium, who earlier this year helped enroll patients in the study, gather samples, and perform experiments. By testing for the presence of these antibodies, she says, “you can almost predict who will become severely ill.”

Looking Ahead

The research team is now looking for the genetic driver behind those auto-antibodies. They could be linked to mutations on the X chromosome and might not affect women.

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Source-Medindia