COVID-19 in rheumatic patients: a prospective cohort study

The influence of the presence of an inflammatory rheumatic disease and its treatment on the severity of and immune response towards (viral) infections is not clear. The emergence and pandemic of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) provides the opportunity to assess these influences on the incidence of COVID-19, its clinical severity, and the antibody response in patients with a rheumatic disease compared to a control population.

The primary objective of this study is to compare the disease severity of COVID-19 between patients with a rheumatic disease and a control population. Disease severity is defined as the (unplanned) hospital admission rate of participants that are both IgM- or IgG-SARS-CoV-2 antibody positive and symptomatic. Symptomatic is defined as symptoms or signs of nasopharyngitis, cough, dyspnea, fever, or any other symptom or sign that may be associated with a viral infection, as assessed by the patient. Unplanned means that elective hospital admissions (e.g., for planned surgery) are excluded.

The secondary objectives include studying the following differences between the groups, and subsequently, within the inflammatory disease group, between conventional disease-modifying anti-rheumatic drug (DMARD, including glucocorticoid) users and biologics users in:
1. Cumulative (6-month) incidence of IgM or IgG antibodies against SARS-CoV-2;
2. Disease severity of hospitalized COVID-19 patients (defined as ICU admission or death);
3. Antibody profile (IgM/G/A, IgG1/3) and repertoire (anti-SP, anti-NP), and IgG antibody avidity.

We will also investigate what people do with regards to use and dosage of DMARDs during the SARS-CoV-2 pandemic. Finally, we will investigate whether potential changes in DMARD use and dosage influence the disease activity.

This is a prospective observational cohort study with a follow-up of 6 months. The first visit will consist of an online survey. This survey will also be completed after 3 and 6 months of follow-up. Two blood tests will also be performed between 1-2 and 4-6 months of follow-up.

The study population will consist of participants with an inflammatory rheumatic disease (i.e. rheumatoid arthritis, psoriatic arthritis and ankylosing spondylitis). These patients will be recruited at the three sites of the Amsterdam Rheumatology & immunology Center, which are Reade and the Amsterdam UMC location VUmc and AMC. Furthermore, each patient will be asked to provide a healthy control without a rheumatic disease (and DMARD use) from their social group or household. These two subjects will have a comparable chance of exposure to SARS-CoV-2. All participants need to be at least 18 years old. We expect to include 4000 patients and 4000 controls.

Our hypothesis is that more hospital admissions will be reported in patients with a rheumatic disease compared to the control population.

Survey: 0, 3, and 6 months; Blood sample: 1-2 and 4-6 months after the baseline survey