Abstract General Information

Title

SARS-CoV-2 infection during AQP4-positive NMOSD relapse hospitalization: CSF and blood immunological findings

Case Report

Case presentation: Here we describe a patient diagnosed with Aquaporin-positive (AQP4-positive) Neuromyelitis Optica spectrum disorder (NMOSD) who manifested bilateral optic neuritis as a relapse. During the hospitalization, the patient tested positive for SARS-CoV-2 infection. Using high-dimensional flow cytometry analyses, we investigated several immunological T cell markers in the cerebrospinal fluid (CSF) and peripheral blood during both conditions. We identified subsets of CD8+ T lymphocytes (CD28-CD57+) associated with serine-protease granzyme-B (GzmB) expression both in the CSF and peripheral blood.
Discussion: Loss of CD28 along with CD57 expression in memory CD8+ T lymphocytes does not result in anergy, but rather in increased GzmB expression, as shown in several conditions. Cytotoxic T subsets have a positive role during antiviral and antitumor immune responses. In this particular case, we hypothesize that enhanced cytotoxic behavior found during NMOSD relapse provided a robust immune response against SARS-CoV-2 infection since our patient had an asymptomatic clinical course of COVID-19. On the other hand, persistent cytotoxic T lymphocytes may worsen or even start blood-brain barrier disruption during NMOSD, allowing the entrance of anti-AQP4 autoantibodies into the central nervous system and resulting in relapses.
Final comments: Besides the asymptomatic SARS-CoV-2 infection, our data emphasize that cytotoxic CD8+ T lymphocytes may be involved in the physiopathology of relapses during AQP4-positive NMOSD.

Area

Immunology and basic Science