Scandinavian Journal of Rheumatology最新文献

Objective: To examine the demographic and clinical features of paediatric familial Mediterranean fever (FMF) patients with a heterozygous Mediterranean fever (MEFV) gene mutation, focusing on colchicine discontinuation and factors linked to sustained remission.

Method: This retrospective study included 2325 paediatric FMF patients followed at a tertiary rheumatology clinic between August 2016 and February 2024. Of these, 1246 carried a heterozygous MEFV mutation, and 87 had stopped colchicine. Discontinuation was either physician decision (PD) or initiated by family/patient decision (FD). Demographic data, clinical symptoms, colchicine use, and MEFV variants were recorded. Patients were monitored after discontinuation to assess remission and the need for retreatment.

Results: Of 87 patients, 47 (54%) were discontinued under PD and 40 (46%) under FD. The median discontinuation age was 10.8 years in PD and 11.7 years in FD. Colchicine was reinitiated in 25 patients (28.7%): 11 (4.0%) from PD and 14 (56.0%) from FD. Drug-free remission was maintained in 62 patients (71.3%), including 36 PD (58.1%) and 26 FD (41.9%) (p = 0.45). The pre-discontinuation asymptomatic period was significantly longer in PD (p < 0.01). PD patients also had a lower risk of reinitiating treatment than FD patients (p = 0.046). Older age at discontinuation was associated with sustained remission (p = 0.01).

Conclusion: Colchicine withdrawal under physician supervision and at older ages is associated with a lower risk of relapse and greater likelihood of maintaining drug-free remission.

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.