Scandinavian Journal of Rheumatology最新文献

Objectives: Interferon regulatory factor 5 (IRF5) plays a central role in interferon-mediated inflammation and is implicated in autoimmune diseases, including systemic lupus erythematosus (SLE). Detecting IRF5 in plasma is challenging due to its low circulating levels, highlighting the need for a highly sensitive and quantitative assay. This study aimed to develop such an assay, validate the existence of previously identified IRF5 high and low subgroups in SLE, and support the potential of IRF5 as a biomarker in precision medicine.

Method: We established a solid-phase proximity ligation assay (SP-PLA) for IRF5 detection using a commercially available polyclonal antibody, which was benchmarked against two in-house recombinant antibodies. A linear calibration curve was generated using recombinant IRF5 protein (range 0.01-100 pg/µL), with a limit of detection between 0.01 and 0.05 pg/µL. EDTA-plasma samples from three SLE subgroups (n = 25 per group) were analysed.

Results: IRF5 was detectable in all SLE plasma samples using SP-PLA (mean 0.63 pg/µL; sd 1.92 pg/µL; maximum 13.54 pg/µL). The IRF5 high SLE subgroup showed significantly higher IRF5 plasma levels than the IRF5 low SLE subgroup (Dunn's post-hoc test, adjusted p < 0.05).

Conclusion: The SP-PLA enabled sensitive and specific detection of low-level IRF5 in plasma and confirmed the presence of IRF5 high and low subgroups in SLE using a quantitative method. These findings support the potential of IRF5 as a biomarker, but validation in independent cohorts is required. The assay may facilitate patient stratification in future research and precision medicine approaches targeting the interferon pathway.

Objective: This study assessed the characteristics, concomitant medications, medication switches, sick leave, disability pensions, and healthcare resource utilization (HCRU) of patients with psoriatic arthritis (PsA) and biological disease-modifying anti-rheumatic drug (bDMARD) purchases in Finland using comprehensive follow-up data from four nationwide registry controllers.

Method: Electronic healthcare data covering adult patients with PsA and reimbursed bDMARD purchases between 2013 and 2021 in Finland were used. Patients were followed from the first bDMARD purchase (first biological cohort) or switch (switcher cohort) to 2022 or until death/loss of follow-up. Patients with bDMARD purchases before 2013 and no switches afterwards were not included.

Results: The study investigated 2546 patients with PsA and bDMARD purchases, with 458 (18.0%) in the switcher cohort and 2088 (82.0%) in the first biological cohort. In the first biological cohort, 22.4% (95% confidence interval 20.6-24.2) switched bDMARD after 12 months. Work absences accumulated before bDMARD initiation and decreased afterwards in the first biological cohort, while switchers maintained a modest linear accumulation. The proportion of under-65-year-old patients on disability pensions was higher in switchers compared to the first biological cohort. HCRU decreased after bDMARD initiation in the first biological cohort (annual cost per patient €5093 vs €4610), while it increased for switchers (€5246 vs €5596).

Conclusion: Patients experienced increasing absenteeism before first bDMARD initiation, indicating an unmet need at treatment initiation. This suggests that earlier medication initiation could be beneficial, as a bDMARD switch with the bDMARD armamentarium available during the study period did not fully address growing absenteeism.

Objectives: The Revised Fibromyalgia Impact Questionnaire (FIQ-R) is a composite questionnaire covering key domains of fibromyalgia disease burden. This study aimed to translate the FIQ-R into Norwegian, to assess face, content, and criterion validity, and to evaluate the psychometric properties of the Norwegian FIQ-R using Rasch analysis, in a sample of adults with fibromyalgia.

Method: The FIQ-R was translated into Norwegian following established methodology in collaboration with patient research partners. Participants attending a patient education session for people with chronic musculoskeletal pain were asked to complete, anonymously, the translated FIQ-R, Fibromyalgia Self-reported Diagnostic Criteria (FSDC), 36-item Short Form Health Survey (SF-36), and Modified Health Assessment Questionnaire (MHAQ). Fibromyalgia cases were identified according to the FSDC. Correlations between FIQ-R, MHAQ, and SF-36 were calculated. Rasch analysis was performed.

Results: In total, 241 participants (96.3% female) were classified as having fibromyalgia according to the FSDC. The translated FIQ-R had acceptable face and content validity. The correlation coefficients were moderate between FIQ-R and SF-36, and strong between FIQ-R and MHAQ. The FIQ-R formed a multidimensional scale, indicating two subscales: FIQ-R function and FIQ-R symptoms. Both subscales showed reversed threshold ordering and were consequently collapsed into five and four response categories, respectively. The resulting subscales were found to have good reliability and targeting.

Conclusion: Owing to the lack of unidimensionality in the FIQ-R, it is recommended that both clinical and research applications rely on subscale scores rather than a total score.

Objective: The aim of the study was to assess the reliability of using the iPhone's built-in Compass application for measuring cervical rotation (CR) degrees in patients with ankylosing spondylitis (AS), compared to traditional methods using an inclinometer and a universal goniometer.

Method: Patients diagnosed with AS and receiving care at our rheumatology outpatient clinic were enrolled in this study. Two examiners measured CR using the iPhone 4 Compass application, an inclinometer, and a universal goniometer. Each measurement was performed twice. Intrarater and interrater reliability were assessed using intraclass correlation coefficients (ICCs), while agreement between methods was analysed by the Bland-Altman method.

Results: The study sample included 30 AS patients (73% male). Excellent intrarater and interrater reliability were observed across all three measurement methods in the entire sample. Bland-Altman analysis showed good agreement between the iPhone and inclinometer, with a mean difference (bias) of -5.6 for Examiner 1 [95% confidence interval (CI) -7.6 to -3.6] and -6.3 for Examiner 2 (95% CI -8.8 to -3.8). The mean differences between the iPhone and universal goniometer measurements were 2.3 for Examiner 1 (95% CI -0.4 to 5.2) and 4.1 for Examiner 2. Similarly, between the universal goniometer and inclinometer, mean differences were -8.0 for Examiner 1 (95% CI -11.2 to -4.8) and -10.4 for Examiner 2.

Conclusion: Through the integration of everyday smartphone technology for clinical use, the iPhone Compass application can be considered a practical and accessible tool for measuring CR in patients with AS, offering potential benefits for clinical practice.

Objectives: To evaluate the relationship between anti-neutrophil cytoplasmic antibody (ANCA) positivity and the disease characteristics, treatment, and prognosis of eosinophilic granulomatosis with polyangiitis (EGPA).

Method: We conducted a retrospective cohort study of patients with new-onset or severely relapsing ANCA-associated vasculitis, enrolled in the J-CANVAS registry. The clinical characteristics at baseline, treatments, and prognoses of ANCA-positive and ANCA-negative patients were assessed.

Results: Three patients with positive proteinase-3 ANCA were excluded, and 166 patients with EGPA (new onset, 159; severe relapse, seven) were included. Sixty-two patients were myeloperoxidase (MPO)-ANCA positive and 104 patients were negative. No differences in age or sex were observed between the two groups. The MPO-ANCA-positive group had significantly more frequent mucous membrane and eye involvement, more frequent renal involvement, higher total Birmingham Vasculitis Activity Score, higher neutrophil counts, and higher C-reactive protein levels at baseline. Although rituximab was administered more frequently in the MPO-ANCA-positive group, no other differences in treatment were found. Both groups had comparable estimated glomerular filtration rates and prednisolone doses at weeks 24 and 48. The incidence rates of severe relapse, minor relapse, and serious infectious diseases were comparable. Cox regression analysis revealed that MPO-ANCA positivity was not a significant factor in serious infectious diseases and relapse.

Conclusion: Patients with MPO-ANCA-positive EGPA demonstrated different baseline clinical characteristics from MPO-ANCA-negative patients. However, subsequent relapses and serious infectious diseases were comparable.

Objective: Systemic lupus erythematosus (SLE) is associated with increased cancer risk. However, the patterns of cancer incidence remain unclear. This study aimed to evaluate the cancer risk in patients with SLE.

Method: This population-based cohort study identified 24 241 patients with newly diagnosed SLE between 2004 and 2020 using Korean National Health Insurance Service data. Patients were followed up until cancer diagnosis, death, or December 2021. Standardized incidence ratios (SIRs) were calculated to compare cancer risk between patients with SLE and the general population. Subgroup analyses were performed based on the age at diagnosis, follow-up duration, and use of immunosuppressive agents.

Results: Patients with SLE had higher risks of overall [SIR 3.3, 95% confidence interval (CI) 3.2-3.4], solid (SIR 3.1, 95% CI 3.0-3.2), and haematological (SIR 9.8, 95% CI 8.9-10.9) cancers compared with the general population. Among solid cancers, liver cancer had the highest risk, followed by ovarian cancer. The relative cancer risk peaked among patients aged 20-39 years (SIR 4.9, 95% CI 4.6-5.2) and during the first year after diagnosis (SIR 4.7, 95% CI 4.3-5.1). The SIRs for haematological, cervical, and lung cancers in cyclophosphamide-treated patients were higher than those for the corresponding cancers in the overall SLE population.

Conclusion: Patients with SLE have increased cancer risk compared with the general population. Increased relative cancer risk is associated with younger age, first year post-diagnosis, and cyclophosphamide treatment.