Characterizing cerebrospinal fluid immunity in neurological manifestations of COVID-19

Patients suffering from Coronavirus disease 2019 (COVID-19) can develop neurological sequelae, such as headache, neuroinflammatory or cerebrovascular disease. These conditions - here termed Neuro-COVID - are more frequent in patients with severe COVID-19. To understand the etiology of these neurological sequelae, we utilized single-cell sequencing and examined the immune cell profiles from the cerebrospinal fluid (CSF) of Neuro-COVID patients compared to patients with non-inflammatory and autoimmune neurological diseases or with viral encephalitis. The CSF of Neuro-COVID patients exhibited an expansion of dedifferentiated monocytes and of exhausted CD4+ T cells. Neuro-COVID CSF leukocytes featured an enriched interferon signature; however, this was less pronounced than in viral encephalitis. Repertoire analysis revealed broad clonal T cell expansion and curtailed interferon response in severe compared to mild Neuro-COVID patients. Collectively, our findings document the CSF immune compartment in Neuro-COVID patients and suggest compromised antiviral responses in this setting. Single-cell RNA sequencing of cerebrospinal fluid-derived leukocytes from patients with Neuro-COVID (n=8), non-inflammatory (n = 9) and autoimmune (n=9) neurological diseases and viral encephalitis (n=5).​