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Scientists Identify Factors That Appear Linked to Long Covid

Scientists seeking to find out which patients are most at risk of developing long Covid offered partial answers in a study.

Scientists Identify Factors That Appear Linked to Long Covid
A doctoral researcher works in  a chemical engineering lab.  (Photographer: Maria Magdalena Arrellaga/Bloomberg)

Scientists seeking to find out which patients are most at risk of developing long Covid offered partial answers in a study.

People who have circulating fragments of the coronavirus, specific antibodies directed against their own tissues or organs -- known as auto-antibodies -- and a resurgence of the Epstein-Barr virus appear more at risk, researchers said in an article in the scientific journal Cell

Scientists are racing to better understand and predict long Covid, in which patients still confront a wide range of health problems months after recovery. The team of more than 50 researchers found some markers that could be identified early and appeared to correlate with lasting symptoms, regardless of whether the initial infection was severe. 

The researchers followed 309 Covid patients from initial diagnosis to convalescence two or three months later and compared them to healthy control subjects. They analyzed blood samples and nasal swabs, integrating the data with patients’ health records and self-reported symptoms. 

After three months, more than half of patients reported fatigue and a quarter reported a lingering cough. Others suffered gastro-intestinal symptoms.

The study results were complex, with different profiles associated with different symptoms. Overall, the scientists pointed to a reactivation of the Epstein-Barr virus -- which usually remains dormant in the body -- and circulating fragments of SARS-CoV-2 at diagnosis as factors that could anticipate long Covid. So did a handful of auto-antibodies, including some associated with lupus. They also found that patients with respiratory symptoms had low levels of the hormone cortisol. 

The researchers found a correlation between type 2 diabetes and cough; that women tended to suffer neurological symptoms; and that patients with heart disease or pre-existing cough tended to experience loss of smell or taste. 

The authors said their findings pointed to potential treatment strategies that include antiviral medicines, since they have an effect on viral load, and cortisol-replacement therapy, for patients who are deficient.

©2022 Bloomberg L.P.