Severe infection with COVID-19 (coronavirus disease 2019) may cause an immune response that damages nerve cells in the brain, leading to delirium, memory and cognitive problems, and may increase long-term risk of health problems.
Scientists at King’s College London have found that the immune response to the virus increases neuronal death and has a “profound” effect on the hippocampal region of the brain, which is responsible for learning and memory. influences.
These are preliminary findings, but say the COVID-19 virus has not directly infected the brains of patients and could still induce neurological problems.
This process is thought to underlie delirium in patients with COVID-19, and may also be a factor in brain fog or other long Covid symptoms.
Delirium is a state of extreme confusion that leaves patients without knowing who they are or where they are。
Study leader Carmine Pariante, professor at King’s College London, said: “These neurological symptoms are very worrying for patients and their families, and we hope our research can help identify the most appropriate treatments to reduce or prevent these symptoms. .”
Researchers analysed blood samples from 36 patients admitted to the Guy’s and St Thomas’ NHS Foundation Trust in London during the first wave of the outbreak and found higher than normal levels of IL-6 protein in their bodies more than 15 times. This protein is released by immune cells to call on other immune cells. In infected patients with delirium, it was found that IL-6 protein was significantly increased, which was as much as 6 times that of other infected patients. Nearly one-third of hospitalized patients infected with the virus developed symptoms of delirium, and the proportion of severely ill patients was as high as two-thirds.
Scientists exposed lab-grown neuronal cells to patient blood to further study how high levels of IL-6 affect neurons in the hippocampus. They found that the blood of delirium patients increases normal neuronal death rates and reduces the production of new brain cells, causing damage that can lead to delirium.
Blocking these proteins protects brain cells from damage, scientists report in the journal Molecular Psychiatry. Janus kinase inhibitors, a drug already used to moderate the dangerous immune response to COVID-19, have the potential to fight delirium and its knock-on effects, the study suggests.
(Editor-in-Chief: Zhuang Yanyu)