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COVID-19

Unraveling the Mystery of Long-COVID: New Research on "Zombie" Cells

Strategic Insights

— 2 min read

Millions of people worldwide have been left with lingering symptoms after recovering from COVID-19, influenza, and other viral infections, which are now classified as long-COVID or post-viral fatigue syndromes. These conditions share many characteristics with myalgic encephalomyelitis or chronic fatigue syndrome (ME/CFS), including chronic fatigue, brain fog, exercise intolerance, and other debilitating symptoms. A new study, led by a researcher from Stellenbosch University, proposes that certain viruses drive endothelial cells, which line the blood vessels, into a "zombie-like" state, contributing to the development of long-COVID and ME/CFS.

Key Takeaways:

  • **"Zombie" endothelial cells:** Viruses such as SARS-CoV-2, Epstein-Barr virus, and influenza A can trigger endothelial senescence, a state where cells stop dividing but continue to release molecules that confuse the immune system, leading to blood clotting, inflammation, and impaired blood flow.
  • **Cellular senescence:** Senescent endothelial cells, also known as "zombie cells," are thought to be responsible for the increase in oxidative stress, inflammation, and oxidative damage in ME/CFS and long-COVID patients.
  • **Immune dysfunction:** Impaired natural-killer cell function, sluggish macrophages, and complement dysfunction enable senescent endothelial cells to evade the immune system, creating a self-sustaining loop of vascular and immune dysfunction.
  • **Clinical implications:** The study suggests that targeting senescent endothelial cells directly may offer a route to healthier blood vessels and improved disease management in ME/CFS and long-COVID patients.
  • **Future research directions:** A registered clinical trial in the US is investigating senescence in long-COVID using non-invasive imaging and fluorescent probes to detect the presence of "zombie cells" in patients.
  • **Therapeutic potential:** Understanding the role of "zombie cells" in ME/CFS and long-COVID may lead to the development of novel treatments that target senescent endothelial cells, improving overall health outcomes for affected individuals.

Statistics:

  • **Estimated 400 million:** Since the start of the pandemic in 2020, over 400 million people have developed long-COVID symptoms, with nearly half of them now meeting the criteria for ME/CFS.
  • **Viral load:** Research suggests that SARS-CoV-2 has the ability to induce senescence in a variety of cell types, including endothelial cells, which can contribute to chronic illness.
  • **Endothelial dysfunction:** Senescent endothelial cells are thought to be responsible for the constriction of blood vessels, limited blood flow, and other symptoms associated with ME/CFS and long-COVID.

Sources:

  • The Conversation -- Africa -- By Burtram C. Fielding, Dean Faculty of Sciences and Professor in the Department of Microbiology, Stellenbosch University
  • World Health Organization
  • United States Centers for Disease Control and Prevention
  • Registered clinical trial in the US (no specific reference number provided)
  • The Conversation article -- "Long-COVID, viruses and 'zombie' cells: new research looks for links to chronic fatigue and brain fog"

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