Background: The best way to manage disease-modifying antirheumatic drugs (DMARDs) in patients with rheumatic and musculoskeletal diseases (RMDs) undergoing the Coronavirus disease (Covid)-19 vaccination and the recommendations regarding the use and timing of immunomodulatory therapies around the time of vaccination are still a matter of debate, due to the difficulties in balancing the vaccination efficacy and safety.

Objectives: To assess the impact of different strategies of antirheumatic treatment management on disease activity around the time of vaccination for Coronavirus disease (Covid)-19 in patients with psoriatic arthritis (PsA).

Methods: We prospectively evaluated patients with PsA in remission or low-disease activity candidate to receive Covid-19 vaccination with mRNA vaccines. Methotrexate (MTX) and leflunomide were withheld 7 days after each dose, whilst biological DMARDs (bDMARDs), were either continued (46.8% of the patients) or withheld (53.2%) from the day of the first dose until 7 days after the second dose. Patients were reassessed after 3 months from enrollment or in case of disease flare.

Results: After the second dose of Covid-19 vaccination 7 patients (5.6%) (6 females) had an articular disease flare each (mean involved joints: 1.29), one patient presented a concomitant worsening of psoriasis, and four patients had an isolated worsening of their psoriasis. All patients received additional treatments with oral GC (n=2) or non-steroidal anti-inflammatory drugs (n=5). Two flares lasted more than one week and required a modification of the ongoing bDMARD. Articular flare incidence (6.8% vs 3%, p=0.259), involved joints (1.4 vs 1.5, p=0.846), disease flare severity, and changes in antirheumatic therapies (1 vs 1, p=0.928) did not differ significantly between the two different bDMARD management strategy groups (continued vs temporary withheld). There was no significant difference in disease activity score for psoriatic arthritis (DAPSA) and C-reactive protein (CRP) after vaccination, but patients who flared up had a higher mean basal DAPSA (7.3 vs 4.1, p=0.046). On binomial logistic regression analysis, we did not find any significant association with gender, age, basal CRP, basal DAPSA, active psoriasis, conventional synthetic DMARDs, or bDMARDs and disease flare.

Conclusion: Our findings suggest that a temporary short halt of bDMARDs could be a viable option in patients with well-controlled PsA undergoing Covid-19 vaccination without increasing the risk of flares, which could be useful to increase T cell response and antibody titres after Covid-19 vaccination.

Disclosure of Interests: None declared