Humoral response to SARS-CoV-2 infection and vaccines against COVID-19 in patients with neuromyelitis optica spectrum disorders: Impact of immunosuppressive treatment

The aim of this study was to evaluate the humoral response to the SARS-CoV-2 infection and vaccination in the NMOSD patients, treated with various immunosuppresants (ISs). Serum IgG against the complete sequence of the receptor binding domain of the spike protein was measured using ELISA SARS-CoV-2 IgG, INEP, Belgrade. Seroconversion occurred in 8/10 patients with COVID-19, and in 5/9 after vaccination. One out of four patients treated with inebilizumab seroconverted (after COVID-19); antibodies were not detected in any of the remaining 3 patients who were vaccinated. Antibodies developed after COVID-19 in 4/5 patients treated with azathioprine and all treated with mycophenolate-mofetil, and after vaccination, in 5/6 patients treated with these ISs. Post-vaccination humoral response was impaired in our NMOSD patients treated with B-cell depleting therapies; seroconversion occurred in almost all patients treated with conventional synthetic disease modifying ISs.