Abstract General Information
SARS-CoV-2 infection during AQP4-positive NMOSD relapse hospitalization: CSF and blood immunological findings
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.
Immunology and basic Science
Vinícius Oliveira Boldrini, Ana Maria Marques, Lucas Scárdua Silva, Rafael Batista João, Alexandre Motta Mecê, Alfredo Damasceno, Fernando Cendes, Alessandro Santos Farias, Clarissa Lin Yasuda