Factors associated with severe infection in rheumatoid arthritis patients: lessons learned from the COVID-19 pandemic.

Purpose: This aimed to identify the factors associated with severe/critical coronavirus disease 2019 (COVID-19) infection in rheumatoid arthritis (RA) patients.

Methods: Two-hundred RA patients diagnosed according to the American College of Rheumatology/ European League Against Rheumatism (ACR/EULAR) classification criteria with proven COVID-19 infection were recruited and categorized according to the world health organization (WHO) COVID-19 severity grading into 2 groups: patients with mild/moderate COVID-19 (n = 164) and patients with severe/critical COVID-19 (n = 36). Comparison between both groups was done to identify the risk factors associated with severe/critical infection. Incidence of RA disease activity flare defined as increase in clinical disease activity index (CDAI) more than 10 points following infection was calculated.

Results: Multivariate analysis identified history of previous serious infection, age > 60 years, and diabetes as factors positively associated, whereas COVID-19 vaccination was negatively associated with severe/critical infection. Following COVID-19 infection, the number of patients with severe/critical COVID-19 who had high RA disease activity and the incidence of flares was significantly higher in comparison to patients with mild/moderate COVID-19 (P < 0.001 and 0.003; respectively).

Conclusion: Age > 60 years, diabetes, and history of previous serious infections are risk factors for severe/critical COVID-19, while vaccination has a protective role in RA patients. Infection particularly when severe is associated with risk of disease flare.