Understanding Why COVID-19 Affects Some Individuals More Severely
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Factors Influencing COVID-19 Severity
Why does COVID-19 have a more devastating impact on certain individuals compared to others? Various factors, including race, age, and pre-existing health issues like obesity, hypertension, and heart disease, play a significant role. Furthermore, individuals undergoing active cancer treatments, such as chemotherapy, may also face heightened vulnerability. It's crucial to also consider vaccination status when evaluating risk.
The onset of life-threatening severe pneumonia, known as acute respiratory distress syndrome (ARDS), can vary greatly among individuals. Below, I will outline some insights gleaned from an article published by the University of California, San Francisco.
“Chaos was the law of nature; Order was the dream of man.”
— Henry Adams, The Education of Henry Adams
Ariel Bleicher highlights a key question: “What we still don’t know, however, is what tips one COVID-19 victim toward ARDS but not another.” It's noteworthy that patients infected with the novel coronavirus exhibit a distinct clinical progression compared to those with ARDS who aren't infected.
Patients with COVID-19 typically experience a more gradual onset of ARDS and often take longer to recover. Their immune system can become overly reactive, attacking its own body and inflicting damage on the lungs, leading to a critical lack of oxygen. This damaging immune response may persist even after the virus has been cleared.
The virus does not restrict its damage to the lungs alone; it can also affect the heart, gastrointestinal tract, brain, blood vessels, and more. In many cases, the immune response can be more detrimental than the direct viral impact itself, resulting in widespread inflammation.
In my recent writing, I discussed how COVID-19 microclots might contribute to long-term symptoms following infection, a condition commonly referred to as long COVID:
Long Covid: Could This Be Why?
MICROCLOTS. DO THEY HELP EXPLAIN the prolonged suffering experienced by some COVID-19 patients?
COVID-19 Disrupts the Immune System
Next, we turn our attention to the COMET (COVID-19 Multi-Phenotyping for Effective Therapies) study, which analyzes blood samples and other bodily fluids from hospitalized patients to explore their genes, immune cells, and various molecules.
Researchers sequenced RNA to identify which genes were activated, providing insights into the genetic responses of a patient’s immune cells to COVID-19. The results reveal that immune cells from patients with mild COVID-19 effectively executed critical virus defense mechanisms. In contrast, severely affected patients, often requiring ICU admission and experiencing ARDS, lacked an essential interferon response.
Bleicher elaborates on this. Our immune system employs several strategies to combat viral infections, with the interferon response being particularly vital. Specialized immune cells act as sentinels, monitoring for viral threats. Upon detection, these cells release warning proteins—interferons—that signal nearby cells to activate antiviral defenses and induce apoptosis in infected cells.
Professor Matthew “Max” Krummel, Ph.D., from UCSF, who co-leads the COMET study, notes that the absence of an interferon response is evident across the immune system.
Cytokine Storm Explained
Without an effective interferon response to limit the virus, COVID-19 spreads rapidly, leading to extensive cellular damage. Infected cells call for help by releasing inflammatory signals (cytokines) into the bloodstream. As white blood cells and antibodies rush to eliminate the virus, a significant inflammatory response ensues, resulting in tissue damage.
What is hindering the interferon response? Approximately ten percent of patients with severe COVID-19 produce antibodies that target interferons. Others may have unidentified antibodies that interfere with the interferon signaling pathway.
Researchers have made a startling conclusion: Hidden autoimmunity may turn a normally manageable infection into a life-threatening condition. Antibodies against interferons could be just the beginning. As we deepen our understanding of these antibodies and their influence on COVID-19, we may gain clearer insights into who is at risk of severe illness.
Thank you for joining me in examining this fascinating research.
Disclaimer: The information provided in this blog is intended for educational purposes only and is not a substitute for professional medical advice. If you seek medical guidance, diagnoses, or treatment, please consult a healthcare professional. I am not liable for any risks or issues that may arise from using or acting upon the information provided in this blog.
The second video title is Why Is Coronavirus Hitting People of Color So Hard? (feat. W. Kamau Bell) - YouTube, which discusses the disproportionate impact of COVID-19 on communities of color.