Dobromir Tanev1, *, Natalia Marinova1, Milena Kirilova1, Ralitsa Robeva2, Lubomir Marinchev1


1Medical Faculty, Sofia University “Sv. Kl. Ohridski” - Sofia, Department of Rheumatology, UMHAT “SofiaMed”, Sofia, Bulgaria  2Medical Faculty, Medical University - Sofia, Department of Endocrinology, Sofia, Bulgaria


Introduction: Rheumatoid arthritis (RA) has been associated with an increased risk of respiratory infections, and the Covid-19 pandemic represents a serious threat for RA patients. Considering the controversy in the scientific literature, the present study aims to investigate the prevalence and severity of Covid-19 in regard to disease-modifying anti-rheumatic drugs (DMARD) treatment in a large group of RA patients treated in a single rheumatologic center.

Methods: A total of 156 patients with RA on biologic or targeted synthetic DMARD (b/tsDMARD) as well as 102 patients on conventional synthetic DMARD (csDMARD) answered a standardized questionnaire focused on the development, symptoms, and complications of Covid-19 infection.

Results: The prevalence of confirmed or suspected Covid-19 infection did not differ between the two investigated therapeutic groups and the prevalence of hospitalization for moderate or severe Covid-19 infection was low (about 5%). No one of the investigated antirheumatic drugs was specifically associated with the Covid-19 development, symptoms or complications. In the group of female RA patients, the prevalence of confirmed (13.6% vs. 22.4%) and suspected (10.6% vs. 17.6%) Covid-19 infection was significantly lower in women on b/tsDMARD compared to csDMARD (p=0.048). 

Conclusion: The therapy with b/tsDMARD in RA patients has not been associated with increased Covid-19 incidence, distinct clinical symptoms, or worse outcomes when compared to csDMARD therapy. Moreover, it might decrease Covid-19 incidence or increase the asymptomatic cases in women with RA. Gender and sex-specific differences in RA and Covid-19 interrelations need further evaluation. 


Rheumatoid arthritis, DMARD, Covid-19-SARS-Cov-2, infection.