A new study suggests that a blood test could one day help determine a person’s long-term risk of contracting Covid.
The study, published Tuesday in the journal Nature Communicationsfound that people who went on to develop prolonged Covid had lower levels of certain antibodies in their blood soon after they were infected with the coronavirus.
If confirmed through larger studies, the finding could help scientists develop a test to predict who might continue to have symptoms on a weekly, monthly, and even yearly basis. after infection.
“We wanted to be able to recognize and identify as early as possible, who is at risk,” said Dr Onur Boyman, author of the new study and a researcher in the immunology department at Zurich University Hospital. long-term Covid. .
Long Covid, a poorly understood condition with no standard definition, diagnosis or treatment, has plagued doctors and researchers worldwide since the pandemic began.
The exact number of long-term Covid patients is unclear, although it is estimated that one third of Covid patients Overall may experience symptoms for as little as a month.
Any early insight into how the patient could become a so-called persistent illness is welcome, outside experts say.
Charles Downs, a Long Covid researcher and an associate professor in the School of Nursing and Health Research at the University of Miami, called the study “very promising.”
“There is no single test, no imaging study, that can be used to make a diagnosis,” he said. “This helps move us in that direction.”
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Boyman’s research began in early 2020, during the first wave of the pandemic. His team followed the patients through the acute phase of infection, then for six months and then for a year when the persistent Covid phenomenon became apparent.
Compare more than 500 Covid patients – some of them have Castle and others have resolved the symptoms, he said.
What was most surprising was how the immune systems in patients who had developed long-term Covid initially responded to the virus.
Such patients in Boyman’s study showed a marked reduction in belong to two immunoglobulins, IgM and IgG3, are antibodies the immune system makes to fight infection. In a healthy immune system, the level of these Immunoglobulins tend to increase in the face of infection.
That antibody level, when combined with other factors, such as middle age and history of asthma, is 75% effective at predicting Covid persistence, Boyman said.
Because the researchers know which patients are suffering from prolonged Covid, further research is needed to determine if the criteria are as accurate as at the onset of the illness.
“These individuals may be at a disadvantage in the first place, and then because of their background in asthma, they may also respond slightly differently to the virus, leading to a false immune response,” he said. “.
Downs, University of Miami, says in his experience, many long-term Covid patients tend to have asthma or some other history of an underlying allergy-related illness, such as a chronic runny nose associated with allergies. related to seasonal allergies.
If confirmed in larger studies, this study could be “an important step forward in directing resources in post Covid-19 clinic for those who need them most,” Dr Kartik Sehgal, a longtime Covid researcher and medical oncologist at the Dana-Farber Cancer Institute in Boston, wrote in an email.
Some notes apply to new research. The patients in the study were infected between April 2020 and August 2021, before the omicron variant was preserved.
It is therefore uncertain whether the findings apply to people who may develop Covid long after a year omicron infection.
Furthermore, the study did not take into account the vaccination status of the participants. Many Covid patients became ill in early 2020, before a vaccine was available.
Claire Steves, senior clinical lecturer at Kings College London, said: “It is important to consider whether these markers are still predictable in vaccinated individuals as more and more people around the world. vaccinated or previously infected.
But “with the number of cases still high, many people are at risk of developing long-term symptoms,” said Steves, who was not involved in the new study. “We urgently need to scale up research on how to prevent this from happening.”
https://www.nbcnews.com/health/health-news/will-get-long-covid-study-may-offer-clues-rcna13436 Who will get Covid long term? Research can provide clues