Severe COVID-19 Alters Immune System and Links to Inflammatory Protein
A recent study funded by the National Institute of Allergy and Infectious Diseases, part of the National Institutes of Health, suggests that severe COVID-19 can lead to long-lasting alterations in the innate immune system. These changes may help explain why the disease can cause damage to various organs and result in widespread inflammation in the body. The findings were published in the journal Cell.
Researchers from Weill Cornell Medicine in New York City examined immune cells and molecules in the blood samples of 38 individuals recovering from severe COVID-19 and other severe illnesses, as well as 19 healthy individuals. Using a new technique, they were able to collect and analyze rare blood-forming stem cells that circulate in the blood, eliminating the need for bone marrow extraction.
The researchers discovered that these rare stem cells, which give rise to immune cells, exhibited changes in gene expression. These changes were passed down to daughter cells, leading to an increased production of immune cells called monocytes. Interestingly, the monocytes from COVID-19 patients showed higher levels of inflammatory cytokines compared to those from healthy individuals or individuals with other illnesses. Remarkably, these alterations in gene expression were observed up to a year after the onset of COVID-19. However, due to the small number of study participants, a direct association between these changes and health outcomes could not be established.
The scientists suspected that an inflammatory cytokine called IL-6 might be involved in initiating the gene expression changes. They tested this hypothesis in both mice with a COVID-19-like disease and humans with COVID-19. In these experiments, some individuals received antibodies that prevented IL-6 from binding to cells at the early stage of illness. The results showed that these mice and individuals displayed fewer alterations in gene expression and lower levels of inflammatory cytokines compared to those who did not receive the antibodies. These findings suggest that IL-6 may play a crucial role in the observed immune system alterations in severe COVID-19.
The study underscores the importance of COVID-19 vaccination in preventing severe illness and its potential long-term effects on the immune system. Vaccines help stimulate the immune system, enabling it to recognize and fight the virus, thereby reducing the risk of severe illness and associated immune dysregulation. By getting vaccinated, individuals not only protect themselves from severe disease but also contribute to alleviating the burden on healthcare systems.
Further research is needed to fully comprehend the mechanisms underlying the alterations in the innate immune system and their implications for long-term health. The findings of this study provide valuable insights into the impact of severe COVID-19 on the immune system and emphasize the continued efforts required to develop effective treatments and preventive measures.
In conclusion, severe COVID-19 can lead to long-lasting alterations in the innate immune system, which may explain the disease’s ability to cause organ damage and widespread inflammation. The study highlights the role of IL-6 in initiating these changes and emphasizes the significance of COVID-19 vaccination in preventing severe illness and reducing the strain on healthcare systems. Further research is necessary to gain a comprehensive understanding of these alterations and their long-term consequences on health.
