A recent study published today in Nature Communications suggests that markers for brain injury are present in the blood for many months after a COVID-19 infection, even when blood tests for inflammation were normal.
The results represent a significant outcome of the COVID-19 Clinical Neuroscience Study (COVID-CNS) conducted by the University of Liverpool and King’s College London, involving scientists from the ISARIC4C Consortium, the Pandemic Institute, and the NIHR BioResource.
According to Professor Benedict Michael, lead researcher and Director of the Infection Neuroscience Laboratory at the University of Liverpool, „During the COVID-19 pandemic, it became clear that a significant proportion of hospitalized patients and even those with mild COVID-19 infection experienced neurological complications. While some neurological ’symptoms‘ were often mild (such as headaches and muscle pains), it was evident that more significant and potentially life-changing new neurological ‚complications‘ occurred, including encephalitis (brain inflammation), seizures, and stroke.“
The COVID-CNS study analyzed samples from over 800 patients admitted to hospitals across England and Wales with COVID-19, of which half had new neurological conditions. The researchers measured brain injury markers, inflammatory proteins (cytokines) in the serum, antibodies, and brain injury proteins (neuroglial proteins). The analysis of these results shows that during the acute phase of the disease, there is a production of important inflammation proteins and markers for brain injury, but surprisingly, robust biomarker evidence for brain damage (neuroglial damage) persists even months after discharge.
According to Professor Michael, „Our study shows that markers for brain injury in the blood are present months after COVID-19, particularly in those who had brain complications caused by COVID-19, although the blood’s inflammatory response has subsided. This suggests the possibility of persistent inflammation and brain injury that may not be detectable through blood tests for inflammation.“
Professor Aras Kadioglu, Head of the Department of Clinical Infections, Microbiology, and Immunology, stated that „Liverpool has been at the forefront of research throughout the pandemic, and this important new study has identified persistent brain injury markers in those who developed neurological complications during COVID-19, even months after their discharge from the hospital.“
Professor Leonie Taams from King’s College London added, „It has been a great privilege to be part of this important interdisciplinary research of the COVID-CNS consortium. By bringing together immunology, neurology, and infection research, we were able to uncover a range of biomarkers associated with the neurological complications of COVID-19. This work could help lay the groundwork for understanding the potential underlying mechanisms of these complications.“
Michael, BD, et al. (2023). The para-infectious brain damage in COVID-19 persists despite attenuated cytokine and autoantibody responses upon follow-up. Nature Communications. doi.org/10.1038/s41467-023-42320-4