Spectrum of neurological manifestations and systematic evaluation of cerebrospinal fluid for SARS-CoV2 in patients admitted to hospital during the COVID-19 epidemic in South Africa (preprint)

Neurological manifestations of COVID-19 are increasingly described in the literature. There is uncertainty whether these occur due to direct neuroinvasion of the virus, para-infectious immunopathology, as result of systemic complications of disease such as hypercoagulability or due to a combination of these mechanisms. Here we describe clinical and radiological manifestations in a sequential cohort of patients presenting to a district hospital in South Africa with neurological symptoms with and without confirmed COVID-19 during the first peak of the epidemic. In these patients, where symptoms suggestive of meningitis and encephalitis were most common, thorough assessment of presence in CSF via PCR for SARS-CoV2 did not explain neurological presentations, notwithstanding very high rates of COVID-19 admissions. Although an understanding of potential neurotropic mechanisms remains an important area of research, these results provide rationale for greater focus towards the understanding of para-immune pathogenic processes and the contribution of systemic coagulopathy and their interaction with pre-existing risk factors in order to better manage neurological disease in the context of COVID-19. These results also inform the clinician that consideration of an alternative diagnosis and treatment for neurological presentations in this context is crucial, even in the patient with a confirmed diagnosis COVID-19.

Rapid, simplified whole blood-based multiparameter assay to quantify and phenotype SARS-CoV-2 specific T cells (preprint)

Rapid tests to evaluate SARS-CoV-2-specific T cell responses are urgently needed to decipher protective immunity and aid monitoring vaccine-induced immunity. Using a rapid whole blood assay requiring minimal amount of blood, we measured qualitatively and quantitatively SARS-CoV-2-specific CD4 T cell responses in 31 healthcare workers, using flow cytometry. 100% of COVID-19 convalescent participants displayed a detectable SARS-CoV-2-specific CD4 T cell response. SARS-CoV-2-responding cells were also detected in 40.9% of participants with no COVID-19-associated symptoms or who tested PCR negative. Phenotypic assessment indicated that, in COVID-19 convalescent participants, SARS-CoV-2 CD4 responses displayed an early differentiated memory phenotype with limited capacity to produce IFN{gamma}. Conversely, in participants with no reported symptoms, SARS-CoV-2 CD4 responses were enriched in late differentiated cells, co-expressing IFN{gamma} and TNF and also Granzyme B. This proof of concept study presents a scalable alternative to PBMC-based assays to enumerate and phenotype SARS-CoV-2-responding T cells, thus representing a practical tool to monitor adaptive immunity in vaccine trials. SummaryIn this proof of concept study, we show that SARS-CoV-2 T cell responses are easily detectable using a rapid whole blood assay requiring minimal blood volume. Such assay could represent a suitable tool to monitor adaptive immunity in vaccine trials.