ARP Rheumatology
ARP Rheumatology

An indexed journal, with free submission and free access to all articles

Devoted to international progress in the research, diagnosis and treatment of rheumatic and musculoskeletal diseases.

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Up to 1000 words, commenting on an article published at ARP Rheumatology within 6 months.

1.375 (2021)Impact Factor
1.463 (2021)Five year Impact Factor
1.40 (2021)CiteScore

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In a community-based setting spondyloarthritis patients report higher levels of physical disability than chronic low back pain patients - results from

Objectives: Chronic low back pain (CLBP) is a common health problem and in most patients it is not possible to identify a specific cause (non-specific CLBP). Spondyloarthritis is a musculoskeletal disorder characterized by (often inflammatory) back pain and spinal stiffness. The impact of CLBP and spondyloarthritis on patients’ physical function may be different. This study aims to compare physical disability in patients with spondyloarthritis and CLBP, in a population-based setting. Furthermore, we aim to identify modifiable risk factors for physical disability among these two populations. Methods: Data from EpiReumaPt, a national health cohort with 10 661 individuals, conducted from September 2011 to December 2013, was used. Physical function was accessed by the Health Assessment Questionnaire Disability Index (HAQ-DI) and by the physical function dimension of the 36-Item Short Form Survey (SF-36). Univariable and multivariable linear regression analyses were used to assess the differences between groups. Factors associated with physical disability were explored for both diseases. Results: We evaluated 92 patients with spondyloarthritis, 1376 patients with CLBP and 679 subjects without rheumatic and musculoskeletal diseases (RMDs). Spondyloarthritis and CLBP patients reported significantly higher levels of disability in HAQ-DI (ß=0.33; p < 0.001 and ß=0.20; p < 0.001, respectively) than subjects without RMDs. In comparison to CLBP patients, spondyloarthritis patients reported higher disability (ß=0.14; p=0.03). The physical domains of SF-36, bodily pain and general health, where more affected in spondyloarthritis patients than in CLBP patients (ß=-6.61; p=0.02 and ß=-5.94; p=0.001, respectively). Spondyloarthritis and CLBP patients had a worse physical summary score (PCS) than mental summary score (MCS), and only PCS was significantly worse in comparison to subjects without RMDs. Factors associated with physical disability in CLBP were low back pain intensity, older age, obesity, multimorbidity, and retirement. Similarly, in spondyloarthritis physical disability was associated with retirement and multimorbidity. Factors associated with lower disability were alcohol consumption and male gender in CLBP, and regular physical exercise was associated with lower disability in both disorders. Conclusions: In this nationwide cohort, spondyloarthritis and CLBP patients reported significant physical disability. Regular physical exercise was associated with lower disability in both diseases.
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Severe infections in Portuguese patients with rheumatoid arthritis under biologic treatment – a multicenter, nationwide study (SIPPRA-B Study)

Introduction: Despite years of experience with biological disease modifying anti-rheumatic drugs (bDMARD) in rheumatoid arthritis (RA), little is known about differences in infectious risk among bDMARDs. The aim of this study was to assess the incidence and type of infections in RA patients on bDMARDs and to determine possible predictors. Methods: A retrospective multicenter cohort study that included patients registered in the Rheumatic Diseases Portuguese Registry ( with RA, and exposed to at least one bDMARD until April 2021. RA patients under bDMARD and with at least one episode of severe infection (SI), defined as infection that requires hospitalization, use of parenteral antibiotics or that resulted in death, were compared to patients with no report of SI. Demographic and clinical data at baseline and at the time of each SI were collected to establish comparisons between different groups of bDMARDs. Comparisons between different bDMARDs were assessed and logistic regression was performed to identify predictors of SI. Results: We included 3394 patients, 2833 (83.5%) female, with a mean age at RA diagnosis of 45.5±13.7 years. SI was diagnosed in 142 of the 3394 patients evaluated (4.2%), totaling 151 episodes of SI. At baseline, patients with SI had a significantly higher proportion of prior orthopedic surgery, asthma, interstitial lung disease, chronic kidney disease and corticosteroid use, higher mean age and longer median disease duration at first bDMARD. Nine patients died (6.0%). Ninety-two SI (60.9%) occurred with the first bDMARD, the majority leading to discontinuation of the bDMARD within 6 months (n=75, 49.7%), while 65 (43.0%) restarted the same bDMARD and 11 (7.3%) switched to another bDMARD (6 of them to a different mechanism of action). In the multivariate analysis, we found that chronic kidney disease, asthma, infliximab, corticosteroid use, interstitial lung disease, previous orthopedic surgery, higher Health Assessment Questionnaire and DAS284V-ESR are independent predictors of SI. Conclusion: This study described the incidence and types of SI among Portuguese RA patients on biologics, identifying several predictors of SI, both globally and with different bDMARDs. Physicians should be aware of the real-word infectious risk in RA patients on bDMARDs when making treatment decisions.
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Effectiveness of biosimilar infliximab CT-P13 compared to originator infliximab in biological-naïve patients with rheumatoid arthritis and axial spondyloarthritis: data from the Portuguese Register

Objectives: To compare the effectiveness of the infliximab biosimilar CT-P13 with originator infliximab over 24 months of follow-up in biological-naïve patients with rheumatoid arthritis (RA) and axial spondyloarthritis (axSpA). Methods: Biological-naïve patients from the Rheumatic Diseases Portuguese Register (, with a clinical diagnosis of RA or axSpA, who were starting either the infliximab biosimilar CT-P13 or the originator infliximab after 2014 (date of market entry of CT-P13 in Portugal), were included. Patients on biosimilar and originator were compared regarding different response outcomes at 3 and 6 months, adjusting for age, sex and baseline C-reactive protein (CRP). The main outcome was the change in DAS28-erytrocyte sedimentation rate (ESR) for RA and the ASDAS-CRP for axSpA. Additionally, the effect of infliximab biosimilar vs originator on different response outcomes over 24 months of follow-up was tested with longitudinal generalized estimating equations (GEE) models. Results: In total, 140 patients were included, 66 (47%) of which with RA. The distribution of patients starting the infliximab biosimilar and the originator was the same between the two diseases (approximately 60% and 40%, respectively). From the 66 patients with RA, 82% were females, mean age was 56 years (SD 11) and mean DAS28-ESR 4.9 (1.3) at baseline. As for the patients with axSpA, 53% were males, mean age was 46 years (13) and mean ASDAS-CRP 3.7 (0.9) at baseline. There were no differences in efficacy between RA patients treated with the infliximab biosimilar and the originator, either at 3 months (∆DAS28-ESR: -0.6 (95% CI -1.3; 0.1) vs -1.2 (-2.0; -0.4)), or at 6 months (∆DAS28-ESR: -0.7 (-1.5; 0.0) vs -1.5 (-2.4; -0.7)). This was also true for patients with axSpA (∆ASDAS-CRP at 3 months: -1.6 (-2.0; -1.1) vs -1.4 (-1.8; -0.9) and at 6 months: -1.5 (-2.0; -1.1) vs -1.1 (-1.5; -0.7)). Results were similar with the longitudinal models over 24 months. Conclusion: There are no differences in effectiveness between the infliximab biosimilar CT-P13 and the infliximab originator in the treatment of biological-naïve patients with active RA and axSpA in clinical practice.
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Coronavirus Disease 19 (COVID-19) complicated with post-viral arthritis

Coronavirus disease 2019 (COVID-19) was reported in Europe in the beginning of February 2020. Typical symptoms included fever, cough and dyspnea, and not much was known about the clinical evolution of the disease. Herein, we report a case of a late complication of COVID-19 infection in a 41-year-old...

Imaging of gout: findings and pitfalls. A pictorial review.

Abstract Gout is the most common crystal arthropathy, accounting for up to 5% of all arthritis. The hallmark of the disease is hyperuricemia with the subsequent deposition of monosodium urate (MSU) crystals in the intra- and extra-articular soft tissues and bones, leading to inflammation of these...

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