BRAIN NEURONAL INTEGRITY IN COVID-19 PATIENTS IN TAIWAN

Abstract Background COVID-19 has caused a global pandemic characterized by severe pneumonia. Brain structure abnormality has been confirmed in COVID-19 patients in the UK biobank [1]. However, it is not clear whether this abnormality is reversible nor if the abnormality could be detected in the early stage of the disease. Aims & Objectives In this study, the pathological effect of COVID-19 on the brain integrity was monitored through the utilization of a brain injury bioindicator, neurofilament light chain (NFL) [2]. It can be released from the brain into the peripheral blood when the brain neuronal axon is injured [3]. The study aimed to assess the correlation between the discharge diagnoses and NFL levels in COVID-infected patients. Method Plasma samples from the National Health Research Institutes (NHRI) Biobank of 400 COVID-19 patients recruited from 24 hospitals across Taiwan were used for NFL analyses by immunoassay. Results Among the successfully analyzed 394 patients, 10 patients (2.5%) showed an NFL level above 200 pg/ml. The mean NFL levels were significantly higher in patients older than 50 years (P <0.0001). Male patients had a higher NFL level than females (P = 0.008). The increase in plasma levels of NFL was the highest in the first 1-7 days after the COVID-19 diagnosis was confirmed, then gradually decreased within a month. Significant higher NFL levels were observed in patients with hospitalization, respiratory or ICU treatment, and oxygen therapy (P <0.0001). Moreover, higher NFL levels were also correlated with discharge diagnoses of cardiovascular, lung, kidney, and other chronic diseases (P ≦ 0.008). Discussion & Conclusion COVID-19 infection may cause brain neuronal injury especially in male patients older than 50 years. In addition, the plasma NFL level was associated with a number of clinical features. The results demonstrated that NFL could be an indicator for assessing the brain neuronal integrity following COVID- 19 infection. References 1.Douaud, G., et al., SARS-CoV-2 is associated with changes in brain structure in UK Biobank. Nature, 2022. 604(7907): p. 697-707. 2.Lee, M.K. and D.W. Cleveland, Neuronal intermediate filaments.Annual review of neuroscience, 1996. 19(1): p. 187-217. 3.Khalil, M., et al., Neurofilaments as biomarkers in neurological disorders. Nature Reviews Neurology, 2018. 14(10): p. 577-589.