Objective:

To investigate immune response against SARS-CoV-2 spike protein in patients treated with anti-complement therapy, Eculizumab.

Background:

Certain Immunomodulatory therapies used to treat autoimmune conditions attenuate immunoglobulin production following SARS CoV-2 vaccination, and may increase susceptibility to COVID-19 infections and/or COVID-19 severity. Here we studied immune response against SARS-CoV-2 vaccine in patients treated with Eculizumab, a disease modifying treatment used for multiple autoimmune conditions including Neuromyelitis Optica Spectrum Disorders (NMOSD).

Design/Methods:

We searched the Stanford Research Repository (STARR) database and identified 38 patients treated with eculizumab, who were tested for SARS-CoV-2-IgG and SARS-CoV-2 Interferon Gamma Release Assay (IGRA). 7/38 patients were on eculizumab at the time of vaccination against SARS-CoV-2 and testing for vaccine immunity. 

Results:

Subjects’ mean age was 49.28±18.7 years (6 females and 1 male) with average duration of eculizumab at the time of first dose of vaccine of 12.7±11.6 months, and the interval between the second dose of vaccine and testing was 7.09±6.2 months. All patients had a positive antibody response to SARS-CoV-2 spike protein IgG (100%). Only 3 patients who had IGRA tested, of which 2 were positive for IGRA (66.66%). Two out of 7 patients (28.6%) had mild lymphopenia at the time of vaccination. Our results contrast with our previously reported cohort of multiple sclerosis patients on anti-CD20 therapy who had 71% (17/24) positive SARS-CoV-2 IGRA but negative for SARS-CoV-2 IgG. These findings are explained by different mechanisms of action for these two medications. 

Conclusions:

Based on our findings, eculizumab preserves both B and T cell immunity against SARS-CoV-2 vaccine. The clinical correlation is to be determined.