Researchers analyzing immune cells from people with long COVID have identified a distinct molecular state in CD14+ monocytes—labeled “LC-Mo”—that was more prevalent among patients whose initial COVID-19 illness was mild to moderate and that tracked with reported fatigue and respiratory symptoms, along with higher levels of inflammatory signaling molecules in blood plasma.
After SARS-CoV-2 infection, long COVID can involve persistent fatigue, difficulty concentrating, breathing problems and neurological complaints that may last for months or years, researchers at Germany’s Helmholtz Centre for Infection Research said in a report describing a new Nature Immunology study. (sciencedaily.com)
The team, led by Prof. Yang Li—head of the “Computational Biology for Individualized Medicine” department and a director at the Centre for Individualised Infection Medicine (CiiM)—worked with collaborators including Prof. Thomas Illig of Hannover Medical School (Medizinische Hochschule Hannover, MHH) and Prof. Jie Sun of the University of Virginia, the research organization said. (sciencedaily.com)
Using immune-cell samples stored in MHH’s central biobank, the researchers applied a single-cell multiomics approach to examine molecular features within individual cells, and also measured cytokine levels in blood plasma, which are often linked to inflammation. They additionally grouped patient data by the severity of the original COVID-19 disease to look for molecular differences associated with lingering symptoms. (sciencedaily.com)
The analysis pointed to a distinct molecular state in circulating CD14+ monocytes—white blood cells involved in immune defense—that the researchers called “LC-Mo.” Dr. Saumya Kumar, identified as the first author, said LC-Mo was particularly prevalent in long COVID patients who previously had mild to moderate COVID-19. (sciencedaily.com)
Kumar said LC-Mo was associated with the severity of fatigue and respiratory symptoms and with elevated cytokine levels in blood plasma. The researchers said the finding adds a lead for studying how immune dysregulation might relate to ongoing symptoms, while noting that the precise role of this cell state in causing long COVID remains to be determined. (sciencedaily.com)
“Long COVID is an extremely complex disease with various manifestations,” Li said, adding that scientists still lack a full understanding of why it develops and persists. Li said the LC-Mo finding could inform future studies, including work on genetic risk factors and individualized medicine approaches. (sciencedaily.com)
According to the research organization’s summary, the work was funded by an ERC Starting Grant (ModVaccine), the COVID-19 Research Network of Lower Saxony (COFONI), the Lower Saxony Centre for AI & Causal Methods in Medicine (CAIMed), and additional public funders. (sciencedaily.com)
