Long COVID patients have specific inflammation patterns in their blood, which may be treatable with immune therapies.
The largest UK study of hospitalized SARS-CoV-2 patients found that long COVID causes persistent inflammation that is detectable in the blood.
More than 650 individuals who were hospitalized with severe COVID-19 were analyzed, and those with long-term symptoms displayed distinct inflammation patterns in their blood.
The analysis of long COVID patients’ symptoms revealed signs of immune system activation. The specific pattern of activation varied based on the predominant symptoms, such as fatigue or cognitive impairment. Imperial College London led the research, indicating that existing drugs that influence the immune system could potentially be beneficial for treating long COVID and should be further explored in clinical trials. The findings were published in the journal Nature Immunology and are the most recent research from two UK-wide collaboratives, PHOSP-COVID and ISARIC-4C, which include scientists and clinicians from Imperial College.Along with researchers from the Universities of Leicester, Edinburgh, and Liverpool, and supported by UK Research and Innovation (UKRI) and the National Institute for Health and Care Research (NIHR).
Professor Peter Openshaw, from Imperial’s National Heart & Lung Institute and a lead investigator for ISARIC-4C, stated: “Given that one in ten SARS-CoV-2 infections result in long COVID and an estimated 65 million individuals worldwide are experiencing persistent symptoms, there is an urgent need for further research to comprehend this condition. Currently, it is extremely difficult to diagnose and treat.
“This investigation includes comprehensive clinical data onThe discovery of inflammatory markers in the blood plasma of individuals experiencing long COVID symptoms is a significant advancement and offers important insights into the causes of the condition. In the most recent study, a group of 426 individuals with persistent long COVID symptoms, who had been hospitalized for COVID-19 at least six months prior, were compared to 233 individuals who had fully recovered from their hospitalization for COVID-19. The researchers analyzed 368 different proteins in blood plasma samples from both groups.recognized for its role in inflammation and modulation of the immune system.
They discovered that, in comparison to individuals who had fully recovered, those with long COVID exhibited a pattern of immune system activation indicating inflammation of myeloid cells and the activation of a group of immune system proteins known as the complement system.
Myeloid cells are produced in the bone marrow and generate various kinds of white blood cells that travel through the blood and move into organs and tissues to respond to damage and infection. The complement system consists of a series of interconnected proteins that are triggered in response to infection or tissue damage. rnrnThe damage. Particularly, excessive activation of the complement system is linked to numerous autoimmune and inflammatory conditions.
Dr Felicity Liew, from Imperial’s National Heart & Lung Institute, stated: “Our research shows that complement activation and myeloid inflammation may be a common characteristic of long COVID following hospitalization, regardless of the type of symptoms.
“It is uncommon to discover evidence of ongoing complement activation several months after the acute infection has cleared, indicating that long COVID symptoms are a result of active inflammation. However, we cannot be certain that this applies to all forms of long COVID.The VID is a concern, particularly if symptoms develop following non-hospitalized infection. The study also identified various subtypes of long COVID and was able to gather detailed data on the symptoms experienced by patients and which ones were most prevalent. It was discovered that certain groups of symptoms were linked to specific proteins, such as increased levels of the marker SCG3 in patients with gastrointestinal symptoms, which has previously been associated with impaired communication between the gut and the brain. In general, there were five common subtypes of symptoms that overlapped.Different types of long COVID have been identified with unique immune signatures, although they all share some common symptoms such as fatigue, cognitive impairment, anxiety, depression, cardiorespiratory issues, and gastrointestinal problems. The researchers note that individuals may experience symptoms from multiple groups and that the groups are not exclusive. The subtypes of long COVID seem to indicate distinct biological mechanisms of the disease, suggesting that different symptoms may have different underlying causes. This information could be valuable in designing clinical trials, particularly for treatments that focus on immune responses.
Inflammation is a key factor in long COVID and can lead to a variety of symptoms.
Treating long COVID may involve the use of IL-1 antagonists, such as anakinra, which are commonly used for rheumatoid arthritis, and JAK inhibitors, used for certain types of cancers and severe rheumatoid arthritis. Both types of drugs target components of the immune system that may be activated in long COVID.
The researchers note that their study had limitations, as it only included hospitalized individuals with severe SARS-CoV-2 infections. However, a significant number of people experiencing long COVID in the general population were not included.
Many people with mild initial SARS-CoV-2 infection only experience mild symptoms, and it is not clear if the same immune processes are involved.
According to Professor Openshaw, “This research strongly suggests that long COVID is the result of inflammation after the initial viral infection, but it is also very complex. We hope that our findings will lead to the development of specific tests and treatments for the different types of long COVID. We believe that a one-size-fits-all approach to treatment may not be effective.
“COVID-19 will have long-lasting effects even after the initial infection has resolved, affecting many people. It is important to understand what is happening in the body and how to treat it effectively.”The immune system’s response is crucial in assisting those affected.”
Both the PHOSP-COVD and ISARIC4C are funded by UK Research and Innovation (UKRI) and the National Institute for Health and Care Research (NIHR), and each includes partner institutions from all four nations of the UK.
