The pathogenesis in how Long COVID developing remains a mystery and truly undefined as to why some people become afflicted by this condition and why others do not. However, investigators are gathering clues towards increasing evidence of how it takes hold.
Annie Antar, MD, PhD, assistant professor of medicine, Johns Hopkins University School of Medicine believes there are 2 ways in which Long COVID might develop and they might be related. She has been examining how delayed viral clearance and viral rebound during acute COVID contribute to the development of Long COVID.
“I think what might be happening is there might be a two-hit hypothesis, where you have one hit, which is like you’re in the minority of people who happen to have virus persist, but then something else happens, and then that’s triggering you to develop the syndrome of Long COVID, while other people who have virus persisting don’t feel the same way,” Antar said.
Antar and coinvestigators studied the relationship between severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viral dynamics during infection. Their findings were published in Clinical Infectious Diseases.
“We observed that slower viral clearance rates during acute COVID-19 were associated with increased risk and more symptoms of Long COVID. Early viral-host dynamics appear to be mechanistically linked to the development of Long COVID,” Antar and her coauthors wrote.1
In terms of biomarkers to help predict Long COVID risk, Antar believes IgA autobody response could be one that is involved, but she acknowledges it could be multifactorial.
“I do think that probably IgA antibody response is a big part of that. There are other parts of your immune system that are involved in clearing virus and viral antigen, things like macrophages, can clear viral antigen from the tissue and destroy it, and also help prompt more of an immune response. So it could be antibody responses, it could be weakened T cell responses, it could be weakened kind of innate responses, things like macrophages that it should be patrolling. So I think all those things are probably involved. And, in terms of biomarkers, the virus itself is a great biomarker,” Antar said.
Ultimately, the understanding of the pathogenesis is still undetermined, but they are getting closer to understanding it. Antar will presenting data from her published paper at the ongoing CROI meeting in San Francisco.
