CSF Biomarkers in Patients With COVID-19 and Neurologic Symptoms: A Case Series

To explore whether hospitalized patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and neurologic symptoms have evidence of CNS infection, inflammation, and injury using CSF biomarker measurements. We assessed CSF SARS-CoV-2 RNA along with CSF biomarkers of intrathecal inflammation (CSF white blood cell count, neopterin, β -microglobulin, and immunoglobulin G index), blood-brain barrier integrity (albumin ratio), and axonal injury (CSF neurofilament light chain protein [NfL]) in 6 patients with moderate to severe coronavirus disease 2019 (COVID-19) and neurologic symptoms who had undergone a diagnostic lumbar puncture. Neurologic symptoms and signs included features of encephalopathies (4 of 6), suspected meningitis (1 of 6), and dysgeusia (1 of 6). SARS-CoV-2 infection was confirmed by real-time PCR analysis of nasopharyngeal swabs. SARS-CoV-2 RNA was detected in the plasma of 2 patients (cycle threshold [Ct] value 35.0-37.0) and in CSF at low levels (Ct 37.2, 38.0, 39.0) in 3 patients in 1 but not in a second real-time PCR assay. CSF neopterin (median 43.0 nmol/L) and β -microglobulin (median 3.1 mg/L) were increased in all. Median immunoglobulin G index (0.39), albumin ratio (5.35), and CSF white blood cell count (