Biomarkers of Neurological Injury for Emerging Viral Threats and Post Viral Disease

Neurotropic viral infection and the ensuant immune response are a significant cause of morbidity and mortality worldwide, which can range in severity from mild to permanent central nervous system (CNS) damage and death. Encephalitic alphaviruses include Venezuelan and eastern equine encephalitis viruses (VEEV and EEEV; Alphavirus; Togaviridae). Injury to the CNS is an important determinant of poor outcome and tools to predict this outcome are lacking. Neurons are the primary target cells of encephalitic alphaviruses where cytopathology plays a major role in CNS dysfunction. Proteins are released following cell death, such as ubiquitin carboxy-terminal hydrolase L1 (UCH-L1) and glial fibrillary acidic protein (GFAP) are neuromarkers of CNS tissue injury which could serve as biomarkers to assess injury severity, monitor disease progression, direct treatment, and as reliable endpoints to help develop novel medical countermeasures. Recent advances in the use of blood-based biomarkers for diagnosis of traumatic brain injury (TBI) which have FDA approved assays have provided a scientific foundation for expanding the biomarker technology to brain damage caused by other CNS pathologies like viral encephalitis. Here we evaluated the ability to detect these biomarkers for encephalitic alphaviruses, encephalitis of unknown origin, and hospitalized patients with severe coronavirus disease (COVID-19). Higher levels of specific biomarkers were detected in patients diagnosed with alphavirus or unknown encephalitis which may be useful in prognosis and treatment guidance of post viral disease. Collectively, our results suggest that these blood-based biomarkers may be a good indicator for brain injury resulting from viral infection.