THE IMPACT of SARS-COV-2 INFECTION on DISEASE ACTIVITY and CLINICAL RESPONSE to BIOLOGICAL DMARDS in PATIENTS with RHEUMATOID ARTHRITIS

ABSTRACT

Background: Infections are a known trigger for Rheumatoid Arthritis (RA) fares.1 It is still unclear whether SARS-Cov-2 infection affects RA disease activity and the clinical response to biological disease-modifying antirheumatic drugs (bDMARDs). Objectives: To evaluate the effect of SARS-Cov-2 infection on disease activity and bDMARD responses in patients with RA. Methods: A retrospective study was carried out in a cohort of RA patients treated with bDMARDs from a tertiary hospital centre. Demographic and clinical data, including occurrence of SARS-Cov-2 infection, were obtained through medical records. Disease activity (DAS28, DAS28-CRP, CDAI and SDAI) and ACR and EULAR bDMARD responses were evaluated at four time points baseline (t1-last evaluation before Covid-19 pandemic), before (t2) and after (t3) SARS-Cov-2 infection and at the end of follow-up (t4-last appointment of 2021). In patients with no record of SARS-Cov-2 infection the middle evaluations were obtained from two random consecutive appointments during Covid-19 pandemic. Statistical analysis (signifcance at p<0.05) was performed using paired t-test, Wilcoxon and McNemar tests for paired samples and unpaired t-test, Mann-Whitney, Fisher and χ2 tests for independent samples according to the type of variable and the presence of normal distribution. Results: Of the 237 patients included, most of them was women [n = 195 (82.3%)], with a mean age of 59.6 ± 10.1 years old and a median [min, max] disease duration of 18 [2, 50] years. The majority presented rheumatoid factor (RF) and/or anti-citrullinated protein antibodies (ACPA) positivity [n = 204 (87.9%)] and radiographic erosions [n = 119 (72.6%)]. The prevalence of SARS-Cov-2 infection was 11.4% (n=27). Mean disease activity was lower after SARS-Cov-2 infection compared to the previous evaluation on all scores used;however, this difference was not statistically signifcant. Nevertheless, when compared to the mean disease activity at the end of follow-up, there were statistically signifcant differences in DAS28-CRP (t2 3.2±1.0 vs. t4 2.8±1.1, p=0.017) and CDAI (t2 11.1±8.1 vs. t4 8.7±6.2, p=0.05) scores. The relative number of patients with no ACR or EULAR bDMARD responses before SARS-Cov-2 infection wasn't different from post infection and at the end of follow-up. At baseline, the infected and uninfected groups were similar regarding gender, age, RF and/or ACPA positiv-ity, erosive disease, disease and biologic treatment durations, baseline disease activity and ACR and EULAR response. The variation in disease activity and the relative number of patients with worsening or improving EULAR and ACR bDMARD responses between t2 and t3 were not signifcantly different in the two groups, as well as between t2 and t4. The prevalence of patients who switched to another bDMARD was signifcantly higher in the group of patients who had Covid-19 [n=4 (14.8%) vs. 9 (4.3%), p=0.047]. The main reason for switching was the ineffectiveness of the therapy (n=11). Conclusion: No worsening of disease activity or ACR and EULAR bDMARD responses was found after SARS-Cov-2 infection in RA patients under bDMARD. However, the later can be explained by the small sample size. Indeed, these patients exhibited a higher rate of switch due to ineffectiveness of therapy, suggesting a negative impact of SARS-Cov2 infection on the disease course.