Prevalence and prognostic relevance of electrocardiographic abnormalities among patients with ANCA-associated vasculitis.

OBJECTIVES: Current guidelines provide limited evidence for cardiovascular screening in ANCA-associated vasculitis (AAV). This study aimed to investigate the prevalence of electrocardiogram (ECG) abnormalities and associations between no, minor or major ECG abnormalities with cardiovascular mortality in AAV patients compared with matched controls. METHOD: Using a risk-set matched cohort design, patients diagnosed with granulomatosis with polyangiitis or microscopic polyangiitis with digital ECGs were identified from Danish registers from 2000-2021. Patients were matched 1:3 to controls without AAV on age, sex, and year of ECG measurement. Associated hazards of cardiovascular mortality according to ECG abnormalities were assessed in Cox regression models adjusted for age, sex, and comorbidities, with subsequent computation of 5-year risk of cardiovascular mortality standardized to the age- and sex-distribution of the sample. RESULTS: A total of 1431 AAV patients were included (median age: 69 years, 52.3% male). Median follow-up was 4.8 years. AAV was associated with higher prevalence of left ventricular hypertrophy (17.5% vs 12.5%), ST-T deviations (10.1% vs 7.1%), atrial fibrillation (9.6% vs 7.5%), and QTc prolongation (5.9% vs 3.6%). Only AAV patients with major ECG abnormalities demonstrated significantly elevated risk of cardiovascular mortality [HR 1.99 (1.49-2.65)] compared with controls. This corresponded to a 5-year risk of cardiovascular mortality of 19.14% (16-22%) vs 9.41% (8-11%). CONCLUSION: Patients with AAV demonstrated a higher prevalence of major ECG abnormalities than controls. Notably, major ECG abnormalities were associated with a significantly increased risk of cardiovascular mortality. These results advocate for the inclusion of ECG assessment into routine clinical care for AAV patients.

Exploring TNFi drug-levels and anti-drug antibodies during tapering among patients with inflammatory arthritis: secondary analyses from the randomised BIODOPT trial.

To evaluate tumour necrosis factor inhibitor (TNFi) drug-levels and presence of anti-drug antibodies (ADAb) in patients with inflammatory arthritis who taper TNFi compared to TNFi continuation. Patients with rheumatoid arthritis, psoriatic arthritis, or axial spondyloarthritis on stable TNFi dose and in low disease activity ≥ 12 months were randomised (2:1) to disease activity-guided tapering or control. Blood samples at baseline, 12- and 18-months were evaluated for TNFi drug-levels and ADAb. In total, 129 patients were randomised to tapering (n = 88) or control (n = 41). Between baseline and month 18, a significant shift in TNFi drug-levels were observed in the tapering group resulting in fewer patients with high drug-levels (change: - 14% [95% CI - 27 to - 1%]) and more with low drug-levels (change: 18% [95% CI 5-31%]). Disease activity was equivalent between groups at 18 months, mean difference: RA - 0.06 (95% CI - 0.44 to 0.33), PsA 0.03 (95% CI - 0.36 to 0.42), and axSpA 0.16 (- 0.17 to 0.49), equivalence margins ± 0.5 disease activity points. ADAb were detected in eight patients, all from the tapering group. TNFi drug-level category or ADAb were not predictive for achieving successful tapering at 18 months. TNFi drug-levels decreased during tapering which indicate adherence to the tapering algorithm. Despite the difference in TNFi drug-levels at 18 months, disease activity remained equivalent, and only few tapering patients had detectable ADAb. These data do not support using TNFi drug-level and/or ADAb to guide the tapering decision but future research with larger trials is needed.Trial registration: EudraCT: 2017-001970-41, December 21, 2017.

Polyautoimmunity in Patients With Anticyclic Citrullinated Peptide Antibody-Positive and -Negative Rheumatoid Arthritis: a Nationwide Cohort Study From Denmark.

OBJECTIVE: This study aimed to compare the prevalence and incidence of polyautoimmunity between anticyclic citrullinated peptide antibody (anti-CCP)-positive and anti-CCP-negative patients with rheumatoid arthritis (RA). METHODS: In a nationwide register-based cohort study, patients with RA (disease duration ≤ 2 yrs) in the DANBIO rheumatology register with an available anti-CCP test in the Register of Laboratory Results for Research were identified. The polyautoimmunity outcome included 21 nonrheumatic autoimmune diseases identified by linkage between the Danish Patient Registry and Prescription Registry. The age- and sex-adjusted prevalence ratio (PR) was calculated by modified Poisson regression to estimate the prevalence at diagnosis in anti-CCP-positive vs anti-CCP-negative patients. The hazard ratio (HR) of polyautoimmunity within 5 years of entry into DANBIO was estimated in cause-specific Cox regression models. RESULTS: The study included 5839 anti-CCP-positive and 3799 anti-CCP-negative patients with RA. At first visit, the prevalence of prespecified polyautoimmune diseases in the Danish registers was 11.1% and 11.9% in anti-CCP-positive and anti-CCP-negative patients, respectively (PR 0.93, 95% CI 0.84-1.05). The most frequent autoimmune diseases were autoimmune thyroid disease, inflammatory bowel disease, and type 1 diabetes mellitus. During a mean follow-up of 3.5 years, only a few (n = 210) patients developed polyautoimmunity (HR 0.6, 95% CI 0.46-0.79). CONCLUSION: Polyautoimmunity as captured through the Danish National Patient Registry occurred in approximately 1 in 10 patients with RA at time of diagnosis regardless of anti-CCP status. In the years subsequent to the RA diagnosis, only a few and mainly anti-CCP-negative patients developed autoimmune disease.

Increased risk of cardiovascular disease preceding diagnosis of incident ANCA-associated vasculitis: a Danish nationwide study.

OBJECTIVE: To examine if patients with ANCA-associated vasculitis (AAV) have an increased risk of cardiovascular disease in the months prior to diagnosis of AAV. METHODS: Using a nested case-control framework, patients with Granulomatosis with polyangiitis and Microscopic polyangiitis were identified through Danish Nationwide Registries from 1996-2021 and matched 1:3 with age- and sex-matched controls without AAV. Each control was assigned the same index date (date of AAV-diagnosis) as their corresponding case. Conditional logistic regression was used to compute adjusted Hazard Ratios (HRs) for major adverse cardiovascular events (MACE), ischemic heart disease, coronary angiogram, heart failure, venous thromboembolism, atrial fibrillation, ischemic stroke, pericarditis, and ventricular arrhythmias/ICD-implantation/cardiac arrest (VA/ICD/CA) within 12 months, 6 months, 3 months, 2 months and 1 month before index date. RESULTS: A total of 2371 patients with AAV (median age: 63yrs, 53.7% male) were matched with 7113 controls. The prevalence of any cardiovascular outcome and MACE within 12 months preceding index date were 10.3% and 2.4% for AAV, compared to 3.8% (HR 3.05[2.48-3.75]) and 1.3% (HR 1.98[1.39-2.82]) of controls. The risk of cardiovascular outcomes was similarly increased in temporal proximity to the diagnosis, with the highest HR at 1 month prior to index date: Any cardiovascular outcome (HR 10.73[7.05-16.32]) and MACE (HR 5.78[2.67-12.52]). In individual analysis, a significantly higher rate was observed for all outcomes (excluding VA/ICD/CA). CONCLUSIONS: AAV disease is associated with an increased risk of cardiovascular disease in the months preceding diagnosis, which underlines the importance of early clinical vigilance toward cardiovascular disease.

Long-term cardiovascular outcomes and temporal trends in patients diagnosed with ANCA-associated vasculitis: a Danish nationwide registry study.

OBJECTIVES: To examine long-term cardiovascular outcomes and temporal trends among patients with ANCA-associated vasculitis (AAV) using Danish nationwide registries. METHODS: Using a cohort design, we examined patients with granulomatosis with polyangiitis (ICD-10: DM31.3) and microscopic polyangiitis (ICD-10: DM3.17) in Denmark from 1996-2018. Hazard ratios (HRs) of cardiovascular outcomes were compared between patients with AAV and age and gender-matched controls. Counterfactual G-estimation of HRs was performed to estimate 5-year absolute risks. Temporal trends were obtained by grouping cohorts into evenly distributed tertiles according to inclusion year. RESULTS: A total of 2306 patients with AAV (median age: 62.9yrs, 52.6% male) were matched with 6918 controls. Median follow-up was 9.5yrs. Patients with AAV had a higher rate of ischaemic heart disease [HR 1.86 (1.62-2.15)], myocardial infarction [HR 1.62 (1.26-2.09)], coronary angiogram [HR 1.64 (1.37-1.96)], percutaneous coronary intervention [HR 1.56 (1.17-2.07)] and ventricular arrhythmias/implantable-cardioverter-defibrillator (ICD)-implantations [HR 2.04 (1.16-3.57)]. Similarly, an increased rate of heart failure [HR 2.12 (1.77-2.54)], deep vein thrombosis [HR 3.13 (2.43-4.05)], pulmonary embolism [HR 4.04 (3.07-5.32)], atrial fibrillation [HR 2.08 (1.82-2.39)], ischaemic stroke [HR 1.58 (1.31-1.90)] and in-hospital cardiac arrest [HR 2.27 (1.49-3.48)] was observed. The 5-year risk of all outcomes were significantly higher (excluding ventricular arrhythmia/ICD-implantations). For temporal trends among patients with AAV, a decreased 3-year risk of cardiovascular mortality was observed over time. CONCLUSIONS: Patients with AAV are at increased risk of heart failure, atrial-/ventricular arrhythmias, venous thrombotic events, ischaemic stroke and myocardial infarction. Furthermore, patients with AAV were more frequently examined with coronary procedures and underwent more coronary revascularizations. No temporal changes in ischaemic cardiovascular outcomes were observed, albeit the cardiovascular mortality has decreased over time.

Infliximab biosimilar-to-biosimilar switching in patients with inflammatory rheumatic disease: clinical outcomes in real-world patients from the DANBIO registry.

OBJECTIVE: Successful uptake of biosimilars in rheumatology is limited by lack of real-world evidence regarding effectiveness of biosimilar-to-biosimilar switching. We investigated infliximab biosimilars CT-P13-to-GP1111 switching among patients with rheumatoid arthritis (RA), psoriatic arthritis (PsA) and axial spondyloarthritis (AxSpA). METHODS: Observational cohort study from the DANBIO registry. Patients were classified as originator-naïve or originator-experienced. Retention rates of 1-year GP1111 treatment were explored (Kaplan-Meier). We identified baseline factors (at the time of switch) associated with withdrawal of GP1111 (multivariable Cox-regression analyses with HRs including originator treatment history). Changes in subjective and objective measures of disease activity 4 months before and after the switch were assessed in individual patients. RESULTS: Of 1605 patients (685 RA, 314 PsA and 606 AxSpA, median disease duration was 9 years, 37% in Clinical Disease Activity Index/Ankylosing Spondylitis Disease Activity Score remission), 1171 were originator-naïve. Retention rates at 1-year were 83% (95% CI: 81% to 85%) and 92% (95% CI: 90% to 95%) for the originator-naïve and originator-experienced, respectively. GP1111 retention rates were higher in originator-experienced compared to originator-naïve with RA (HR=0.4 (95% CI: 0.2 to 0.7)) and PsA (HR=0.2 (95% CI: 0.1 to 0.8)), but not significantly for AxSpA: HR=0.6 (95% CI: 0.3 to 1.2). Lower disease activity was associated with higher retention. Changes in disease activity preswitch and postswitch were close to zero. CONCLUSION: This real-world observational study of more than 1600 patients with inflammatory arthritis showed high 1-year retention following a nationwide infliximab biosimilar-to-biosimilar switch. Retention was higher in originator-experienced and in patients with low disease activity, suggesting outcomes to be affected by patient-related rather than drug-related factors.

Drug survival of biologics and novel immunomodulators for rheumatoid arthritis, axial spondyloarthritis, psoriatic arthritis, and psoriasis - A nationwide cohort study from the DANBIO and DERMBIO registries.

OBJECTIVE: Drug survival is an important proxy measure for effectiveness of treatments for inflammatory diseases such as rheumatoid arthritis (RA), axial spondyloarthritis (AxSpA), psoriatic arthritis (PsA), and psoriasis. The objective of this study was to examine the real-life drug survival of biologics and novel small-molecule therapies across various disease entities such as RA, AxSpA, PsA, and psoriasis. METHODS: We performed a nationwide cohort study using the prospective nationwide registries DANBIO and DERMBIO, comprising all patients treated with biologics or novel small-molecule therapies for RA, AxSpA, PsA, and psoriasis between January 2015 through May 2021 (DANBIO) and November 2009 to November 2019 (DERMBIO). Drug survival was visualized using Kaplan-Meier curves, and Cox proportional hazards models were used to calculate adjusted Hazard Ratios (HRs) with 95% confidence intervals (CIs) for risk of discontinuing therapy. FINDINGS: The study comprised a total of 12,089 patients (17,903 treatment series), including 5,104 RA patients (7,867 series), 2,157 AxSpA patients (3,016 series3), 2,551 PsA patients (3,313 series), and 2,577 psoriasis patients (3,707 series). In confounder-adjusted models drug survival in RA was highest for rituximab followed by baricitinib, etanercept and tocilizumab respectively. For AxSpA, drug survival was high for golimumab compared to all other drugs, followed by secukinumab and etanercept and lowest for infliximab. For PsA, tofacitinib and infliximab had the lowest drug survival compared to all other drugs. All other drugs performed almost equally well with a tendency of a somewhat higher drug survival for golimumab, followed by secukinumab and ixekizumab. For psoriasis, drug survival was generally highest for guselkumab. INTERPRETATION: Differing treatment responses to drugs with various modes of action across RA, AxSpA, PsA and psoriasis emphasize that although these diseases have many overlaps in their pathogenesis, there is a need for an individualized treatment approach that considers the underlying disease, patient profile, and treatment history. FUNDING: None.

Are fatty acids associated with disease activity and biomarkers in patients with psoriatic arthritis? Data from a multicenter clinical trial.

The pathogenesis of psoriatic arthritis (PsA) involves inflammation and bone and soft tissue turnover. Dietary fatty acids have previously been associated with pro-inflammatory effects induced by saturated fatty acids (SFA) and anti-inflammatory effects achieved by at least some polyunsaturated fatty acids (PUFA). The aim of the study was to investigate the correlations between the content of fatty acids in granulocytes and clinical and biochemical markers of PsA. A total of 140 patients with PsA were included. Skin and joint disease activity were assessed. Fatty acid composition in granulocytes was determined by gas chromatography. Competitive enzyme-linked immunosorbent assays were used to assess bone and soft tissue turnover. The content of SFA, n-6 PUFA or n-3 PUFA in granulocytes was not associated with disease activity. Marine n-3 PUFA was significantly positively correlated with collagen degradation. In contrast, n-6 PUFA was significantly positively correlated with collagen formation and negatively correlated with collagen degradation. However, the correlations were all weak. No association was found between the content of fatty acids in granulocytes and disease activity in this population of patients with PsA. The correlation between fatty acids and biomarkers of bone and soft tissue turnover needs further investigation.

Intake of marine n-3 polyunsaturated fatty acids and the risk of rheumatoid arthritis: protocol for a cohort study using data from the Danish Diet, Cancer and Health cohort and Danish health registers.

INTRODUCTION: Rheumatoid arthritis (RA) is a chronic autoimmune inflammatory joint disease with multifactorial aetiology. Smoking is a well-established lifestyle risk factor, but diet may also have an impact on the risk of RA. Intake of the major marine n-3 polyunsaturated fatty acids in particular eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) have been hypothesised to lower the risk of RA due to their anti-inflammatory effects, although based on limited knowledge. Therefore, we aim to investigate the associations between dietary intake of EPA and DHA and the risk of incident RA. METHODS AND ANALYSIS: A cohort study. The follow-up design will be based on data from the Danish Diet, Cancer and Health cohort, which was established between 1993 and 1997. The participants will be followed through record linkage using nationwide registers including the Danish Civil Registration System, the Danish National Patient Registry and the Danish National Prescription Registry using the unique Civil Personal Registration number. Time-to-event analyses will be conducted with RA as the outcome of interest. The participants will be followed from inclusion until date of RA diagnosis, death, emigration or end of follow-up. HRs with 95% CIs obtained using Cox proportional hazard regression models, with age as underlying time scale and adjustment for established and potential risk factors, will be used as measures of association. ETHICS AND DISSEMINATION: The study has been approved by the Data Protection Committee of Northern Jutland, Denmark (2019-87) and the North Denmark Region Committee on Health Research Ethics (N-20190031). Study results will be disseminated through peer-reviewed journals and presentations at international conferences.

Effect of n-3 PUFA on extracellular matrix protein turnover in patients with psoriatic arthritis: a randomized, double-blind, placebo-controlled trial.

Psoriatic arthritis (PsA) is a chronic inflammatory disease characterized by involvement of skin, axial and peripheral skeleton. An altered balance between extracellular matrix (ECM) formation and breakdown is a key event in PsA, and changes in ECM protein metabolites may provide insight to tissue changes. Dietary fish oils (n-3 PUFA) might affect the inflammation driven tissue turnover. The aim was to evaluate ECM metabolites in patients with PsA compared to healthy individuals and investigate the effects of n-3 PUFA. The 24-week randomized, double-blind, placebo-controlled trial of PUFA included 142 patients with PsA. Fifty-seven healthy individuals were included for comparison. This study is a sub-study investigating biomarkers of tissue remodelling as secondary outcomes. Serum samples at baseline and 24 weeks and healthy individuals were obtained, while a panel of ECM metabolites reflecting bone and soft tissue turnover were measured by ELISAs: PRO-C1, PRO-C3, PRO-C4, C1M, C3M, C4M, CTX-I and Osteocalcin (OC). C1M, PRO-C3, PRO-C4 and C4M was found to be elevated in PsA patients compared to the healthy individuals (from 56 to 792%, all p < 0.0001), where no differences were found for OC, CTX-I, PRO-C1 and C3M. PRO-C3 was increased by 7% in patients receiving n-3 PUFA after 24 weeks compared to baseline levels (p = 0.002). None of the other biomarkers was changed with n-3 PUFA treatment. This indicates that tissue turnover is increased in PsA patients compared to healthy individuals, while n-3 PUFA treatment for 24 weeks did not have an effect on tissue turnover. Trial registration NCT01818804. Registered 27 March 2013-Completed 18 February 2016. https://clinicaltrials.gov/ct2/show/NCT01818804?term=NCT01818804&rank=1.

Comparative effectiveness of two adalimumab biosimilars in 1318 real-world patients with inflammatory rheumatic disease mandated to switch from originator adalimumab: nationwide observational study emulating a randomised clinical trial.

OBJECTIVES: In 2018, a nationwide mandatory switch from originator to biosimilar adalimumab was conducted in Denmark. The available biosimilar was GP2017 (Hyrimoz) in Eastern regions and SB5 (Imraldi) in Western regions. We aimed to assess the comparative effectiveness of GP2017 versus SB5 in patients with rheumatoid arthritis (RA)/psoriatic arthritis (PsA)/axial spondyloarthritis (AxSpA). METHODS: Observational cohort study based on the DANBIO registry with geographical cluster pseudo-randomisation, analysed by emulating a randomised clinical trial. Main outcome was adjusted 1-year treatment retention (Cox regression). Furthermore, 6 months' remission rates (logistic regression), reasons for withdrawal and back-switching to originator were investigated (overall and stratified by indication). RESULTS: Overall, of 1570 eligible patients, 1318 switched and were included (467 RA/321 PsA/530 AxSpA); 623 (47%) switched to GP2017, 695 (53%) to SB5. Baseline characteristics of the two clusters were largely similar, but some differences in registration practice were observed. The combined 1-year retention rate for the two biosimilars was 89.5%. Compared with SB5, estimated risk of withdrawal for GP2017 was lower (HR 0.60; 95% CI 0.42 to 0.86) and 6 months' remission rate was higher (OR 1.72; 95% CI 1.25 to 2.37). Stratified analyses gave similar results (statistically significant for RA). During 1 year, 8.5% and 12.9% withdrew GP2017 and SB5, respectively (primarily lack of effect and adverse events), of whom 48 patients (3.6%) back-switched. CONCLUSION: This head-to-head comparison of GP2017 versus SB5 following a mandatory switch from the originator indicated differences in effectiveness in routine care. This may reflect a true difference, but other explanations, for example, differences in excipients, differences between clusters and residual confounding cannot be ruled out.

Smoking associates with distinct clinical phenotypes in patients with systemic lupus erythematosus: a nationwide Danish cross-sectional study.

OBJECTIVES: SLE displays large clinical heterogeneity that beyond genetic factors may be determined by environmental exposures. In this Danish nationwide study, we aimed to determine if clinical subsets of SLE were associated with smoking history. METHODS: At each of six participating centres, incident or prevalent inpatients and outpatients with SLE were consecutively included. Manifestations forming the basis of SLE classification were registered in an electronic chart system. Patients also provided questionnaire-based data on environmental exposures, including smoking history. Hierarchical cluster analysis was conducted to determine and characterise subsets of patients with similar traits of disease manifestations. Levels of smoking exposure by pack-years were correlated to the identified SLE subsets, as well as discrete SLE manifestations. RESULTS: The cohort consisted of 485 patients (88% women and 92% Caucasian) with SLE of which 51% were ever smokers. Common disease manifestations comprised non-erosive arthritis (81%), malar rash (57%), lymphopenia (55%), photosensitivity (50%) and persistent proteinuria (41%). We identified three distinct phenotypic clusters characterised by their preponderance of (A) neurological, serosal and mucosal involvement; (B) renal, haematological and immunological disorders; and (C) acute and chronic skin manifestations. Cluster B was the youngest and had the lowest level of smoking exposure. Age-adjusted regression analyses showed that compared with never smokers a smoking history of >20 pack-years was associated with neurological disorder (OR=3.16), discoid rash (OR=2.22), photosensitivity (OR=2.19) and inversely with haematological disorder (OR=0.40), renal disorder (OR=0.40) and non-erosive arthritis (OR=0.45), p<0.05 for all. CONCLUSIONS: Our findings support that SLE presents in varying clinical phenotypes and suggest that they may have differentiated associations with smoking history.

Is pain associated with premature mortality in patients with psoriatic arthritis? A nested case-control study using the DANBIO Register.

OBJECTIVES: It has been hypothesized that the presence of chronic pain causes excess mortality. Since chronic pain is prevalent among patients with PsA this potential association should be explored. We aimed to investigate whether higher cumulative pain intensity is associated with an excess mortality risk in patients with PsA. METHODS: A nested case-control study using data from the nationwide DANBIO Register (Danish Database for Biological Therapies in Rheumatology) Register and Danish healthcare registers. Cases were patients who died and corresponding to the date of death, matched on sex, year of birth and calendar period at the time of death with up to five controls. Exposure of interest was mean pain intensity reported during the time followed in routine rheumatology practice. Pain intensity was measured using a visual analogue scale from 0 to 100 and conditional logistic regression was used to calculate odds of mortality per 5 unit increase in pain while adjusting for confounders. RESULTS: The cohort consisted of 8019 patients. A total of 276 cases were identified and matched with 1187 controls. Higher mean pain intensity was associated with increased odds of mortality [odds ratio 1.06 (95% CI 1.02, 1.10)] in the crude model, but there was no association [odds ratio 0.99 (95% CI 0.95, 1.03)] when adjusting for additional confounders. Factors shown to increase the odds of mortality were recent glucocorticoid use, concomitant chronic obstructive pulmonary disease, diabetes mellitus, cancer and cardiovascular disease. CONCLUSION: These results indicate that experienced pain in itself is not associated with premature mortality in patients with PsA. However, recent glucocorticoid use and concurrent comorbidities were.

A novel biomarker of MMP-cleaved prolargin is elevated in patients with psoriatic arthritis.

Psoriatic arthritis (PsA) is a chronic musculoskeletal inflammatory disease found in up to 30% of psoriasis patients. Prolargin-an extracellular matrix (ECM) protein present in cartilage and tendon-has been previously shown elevated in serum of patients with psoriasis. ECM protein fragments can reflect tissue turnover and pathological changes; thus, this study aimed to develop, validate and characterize a novel biomarker PROM targeting a matrix metalloproteinase (MMP)-cleaved prolargin neo-epitope, and to evaluate it as a biomarker for PsA. A competitive ELISA was developed with a monoclonal mouse antibody; dilution- and spiking-recovery, inter- and intra-variation, and accuracy were evaluated. Serum levels were evaluated in 55 healthy individuals and 111 patients diagnosed with PsA by the CASPAR criteria. Results indicated that the PROM assay was specific for the neo-epitope. Inter- and intra- assay variations were 11% and 4%, respectively. PROM was elevated (p = 0.0003) in patients with PsA (median: 0.24, IQR: 0.19-0.31) compared to healthy controls (0.18; 0.14-0.23) at baseline. AUROC for separation of healthy controls from PsA patients was 0.674 (95% CI 0.597-0.744, P < 0.001). In conclusion, MMP-cleaved prolargin can be quantified in serum by the PROM assay and has the potential to separate patients with PsA from healthy controls.

Dosage reduction and discontinuation of biological disease-modifying antirheumatic drugs in patients with rheumatoid arthritis, psoriatic arthritis and axial spondyloarthritis: protocol for a pragmatic, randomised controlled trial (the BIOlogical Dose OPTimisation (BIODOPT) trial).

INTRODUCTION: The The BIOlogical Dose OPTimisation (BIODOPT) trial is a pragmatic, multicentre, randomised controlled, open-label, parallel-group, equivalence study designed to evaluate tapering of biological disease-modifying antirheumatic drugs (bDMARDs) in patients with rheumatoid arthritis (RA), psoriatic arthritis (PsA) and axial spondyloarthritis (axSpA) in sustained clinical remission or low disease activity (LDA). Traditionally, these patients maintain standard dosage of bDMARD lifelong; however, recent studies indicate that a significant proportion of patients in sustained remission or LDA can taper their bDMARD and maintain stable disease activity. Thus, this trial aims to evaluate whether a disease activity-guided tapering strategy for bDMARDs will enable a significant dosage reduction while maintaining disease activity compared with usual care. From the individual patient's standpoint as well as from a societal perspective, it would be advantageous if bDMARDs could be reduced or even discontinued while maintaining disease activity. METHODS AND ANALYSIS: A total of 180 patients with RA, PsA or axSpA treated with bDMARDs and in clinical remission/LDA during the past 12 months will be enrolled from four centres in Denmark. Patients will be randomised in a ratio of 2:1 to either disease activity-guided tapering of bDMARDs (intervention group) or continuation of bDMARDs as usual care (control group).The primary objective is the difference between the two groups in the proportion of patients who have reduced their inclusion dosage of bDMARDs to 50% or less while maintaining stable disease activity at 18 months follow-up. ETHICS AND DISSEMINATION: The study is approved by the ethics committee of Northern Jutland, Denmark (N-20170073) and by the Danish Medicine Agency. Patient research partner KHH contributed to refinement of the protocol and approved the final manuscript. Results will be disseminated through publication in international peer-reviewed journals. TRIAL REGISTRATION NUMBER: 2017-001970-41; Pre-results.

To switch or not to switch: results of a nationwide guideline of mandatory switching from originator to biosimilar etanercept. One-year treatment outcomes in 2061 patients with inflammatory arthritis from the DANBIO registry.

OBJECTIVES: Real-world evidence on effectiveness of switching to biosimila r etanercept is scarce. In Denmark, a nationwide guideline of mandatory switch from 50 mg originator (ETA) to biosimilar (SB4) etanercept was issued for patients with rheumatoid arthritis (RA), psoriatic arthritis (PsA) and axial spondyloarthritis (AxSpA) in 2016. Clinical characteristics and treatment outcomes were studied in ETA-treated patients, who switched to SB4 (switchers) or maintained ETA (non-switchers). Retention rates were compared with that of a historic cohort of ETA-treated patients. Switchers who resumed ETA treatment (back-switchers) were characterised. METHODS: Observational cohort study based on the DANBIO registry. Treatment retention was explored by Kaplan-Meier plots and Cox regression (crude, adjusted). RESULTS: 1621 (79%) of 2061 ETA-treated patients switched to SB4. Disease activity was unchanged 3 months' preswitch/postswitch. Non-switchers often received 25 mg ETA (ETA 25 mg pens/syringes and powder solution were still available). One-year adjusted retention rates were: non-switchers: 77% (95% CI: 72% to 82%)/switchers: 83% (79% to 87%)/historic cohort: 90% (88% to 92%). Patients not in remission had lower retention rates than patients in remission, both in switchers (crude HR 1.7 (1.3 to 2.2)) and non-switchers (2.4 (1.7 to 3.6)). During follow-up, 120 patients (7% of switchers) back-switched to ETA. Back-switchers' clinical characteristics were similar to switchers, and reasons for SB4 withdrawal were mainly subjective. CONCLUSION: Seventy-nine per cent of patients switched from ETA to SB4. After 1 year, adjusted treatment retention rates were lower in switchers versus the historic ETA cohort, but higher than in non-switchers. Withdrawal was more common in patients not in remission. The results suggest that switch outcomes in routine care are affected by patient-related factors and non-specific drug effects.

[Acute abdominal vasculitis in rheumatic diseases].

Mesenteric vasculitis is the most common abdominal manifestation of vasculitis and can present as acute abdominal pain. Mesenteric vasculitis is most frequent in systemic lupus erythematosus and polyarteritis nodosa in adulthood and immunoglobulin A-vasculitis in childhood. Involvement of other organs is also seen. The diagnosis can be challenging, but detailed clinical assessment in combination with diagnostic tests often identifies the underlying cause. Medical treatment is used, when the abdominal manifestation is considered reversible, while surgery is used in unstable patients or patients with non-reversible conditions.

A nationwide non-medical switch from originator infliximab to biosimilar CT-P13 in 802 patients with inflammatory arthritis: 1-year clinical outcomes from the DANBIO registry.

OBJECTIVES: According to guidelines, a nationwide non-medical switch from originator (INX, Remicade) to biosimilar infliximab (Remsima, CT-P13) was conducted in Danish patients with rheumatoid arthritis (RA), psoriatic arthritis (PsA) and axial spondyloarthritis (AxSpA). We investigated disease activity before/after switching and retention rates in the DANBIO registry. METHODS: Disease activities 3 months before and after switch and changes over time were calculated. Flare was defined as change in 28 Joint Disease Activity Score (∆DAS28) ≥1.2 (RA/PsA) or Ankylosing Spondylitis Disease Activity Score (∆ASDAS) ≥1.3 (AxSpA). Crude and adjusted retention rates were compared with a historic cohort of INX-treated patients. RESULTS: Eight hundred and two patients switched (403 RA/120 PsA/279 AxSpA; 51% women, age (median (IQR): 55 (44-66)) years). Follow-up was 413 (339-442) days. Prior INX treatment duration was 6.8 (4.3-9.5) years. Disease activities were similar 3 months before/after switch. Crude 1-year CT-P13 retention rate (84.1 (95% CI 81.3 to 86.5)) was similar to the historic IFX cohort (86.2 (95% CI 84.0 to 88.0), p=0.22). The adjusted absolute retention rates were 83.4 (95% CI 80.8 to 86.2) and 86.8% (95% CI 84.8 to 88.8), respectively (p=0.03). In total 132 patients withdrew (lack of effect: 71/132=54%, adverse events: 37/132=28%). Patients with previous INX treatment duration >5 years had longer CT-P13 retention. CONCLUSION: In 802 arthritis patients treated with INX for median >6 years, a nationwide non-medical switch to CT-P13 had no negative impact on disease activity. Adjusted 1-year CT-P13 retention rate was slightly lower than for INX in a historic cohort.