B-Cell Depletion Influences SARS-CoV-2 Antibody Production in Patients With MS

Illustration of antibodies (y-shaped) responding to an infection with the new coronavirus SARS-CoV-2. The virus emerged in Wuhan, China, in December 2019, and causes a mild respiratory illness (covid-19) that can develop into pneumonia and be fatal in some cases. The coronaviruses take their name from their crown (corona) of surface proteins, which are used to attach and penetrate their host cells. Once inside the cells, the particles use the cells’ machinery to make more copies of the virus. Antibodies bind to specific antigens, for instance viral proteins, marking them for destruction by other immune cells, such as the macrophage white blood cell behind the virus.
In order to assess asymptomatic infections and immunologic responses to COVID-19, a team of researchers tested for SARS-CoV-2 antibodies in a multiple sclerosis cohort.

B-cell depletion in patients with multiple sclerosis (MS) may affect production of antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), according to study findings published in JAMA Neurology.

This study included 546 patients with MS (mean age, 46.9 years) who had visited the MS Center Amsterdam in Amsterdam, the Netherlands, within the previous 2 years. Study investigators drew blood samples to measure SARS-CoV-2 antibodies.

Approximately 1 week later, participants completed digital questionnaires to provide data on patient characteristics, current disease-related complaints, and COVID-19 symptoms. The study investigators obtained other MS-specific data from participants’ medical files.

Approximately 11.7% (n=64) of patients had detectable SARS-CoV-2 antibodies in their blood. A total of 35 patients developed COVID-19, which was determined by polymerase chain reaction (PCR) testing. Up to 11% (n=4 patients) of those who tested positive by PCR tested negative for SARS-CoV-2 antibodies.

No COVID-19 symptoms were reported in 9 patients who tested positive for SARS-CoV-2 antibodies. Loss of taste/smell was the most frequently reported symptom in 47% of patients who tested positive. Only 2.9% of patients without SARS-CoV-2 antibodies reported a loss of taste or smell. No deaths were recorded in the MS cohort of patients who developed COVID-19.

The majority of patients (74.2%) received treatment with disease-modifying drugs. Among patients treated with these therapies, the study investigators observed less prevalent SARS-CoV-2 antibodies in those who used injectable drugs (interferon β and glatiramer acetate) compared with patients who used other treatments (4% vs 13.1%, respectively; P =.04).

Patients treated with ocrelizumab had a lower median SARS-CoV-2 antibody response than patients treated with other therapies (0.2 nOD vs 2.5 nOD, respectively; P <.001). Additionally, patients who took ocrelizumab were considered B-cell depleted at a median of 2.5 (0-41) days prior to antibody response measurement. At that time, none of the patients showed signs of hypogammaglobulinemia.

A potential limitation of this study was the low proportion of patients who tested positive for SARS-CoV-2.

Despite this limitation, the study investigators concluded that their findings imply that “B-cell depletion could influence SARS-CoV-2 antibody production in patients with MS” and that these findings could hold “important consequences for humoral immunity after COVID-19 infection and possibly vaccination.”

Disclosure: Several study authors declared affiliations with the pharmaceutical industry. Please see the original reference for a full list of authors’ disclosures.


van Kempen ZLE, Strijbis EMM, Al MMCT, et al. SARS-CoV-2 antibodies in adult patients with multiple sclerosis in the Amsterdam MS cohort. JAMA Neurol. Published online April 30, 2021. doi:10.1001/jamaneurol.2021.1364