Rheumatoid Factor-positive Juvenile Idiopathic Arthritis Research Articles

How common is remission in rheumatoid factor-positive juvenile idiopathic arthritis patients? The multicenter Pediatric Rheumatology Academy (PeRA) research group experience

ObjectiveRheumatoid factor (RF)-positive polyarthritis is the least common type of juvenile idiopathic arthritis (JIA). Functional disability in RF-positive polyarthritis patients is much more severe than in patients with other subtypes; but data on this subtype alone is limited. This study aimed to analyze clinical features, long-term follow-up, treatment response, and remission status in a large multicenter cohort of RF-positive polyarthritis patients.MethodsThis retrospective study included RF-positive polyarthritis patients that were followed up for ≥ 6 months between 2017 and 2022 by the Pediatric Rheumatology Academy (PeRA)-Research Group (RG). Data on patient demographics, clinical and laboratory characteristics were obtained from medical charts. JIA treatments and duration of treatment were also recorded. The patients were divided into 2 groups based on methotrexate (MTX) response, as follows: group 1: MTX responsive, group 2: MTX unresponsive. Clinical and laboratory findings were compared between the 2 groups.ResultsThe study included 56 (45 female and 11 male) patients. The median age at onset of RF-positive polyarthritis was 13.2 years [(interquartile range) (IQR): 9.0–15.0 years] and the median duration of follow-up was 41.5 months (IQR: 19.5–75.7 months). Symmetrical arthritis affecting the metacarpophalangeal and proximal interphalangeal joints of the hands was commonly observed. Subcutaneous MTX was the preferred initial treatment; however, it was ineffective in 39 (69.6%) of the patients. Of 25 patients followed for 24 months, 56% still had active disease at 24 months.ConclusionDuring 2 years of treatment, 44% of RF-positive polyarthritis patients have inactive disease, and they should be considered as a distinct and important clinical entity requiring aggressive and early treatment.

A Comparison of International League of Associations for Rheumatology and Pediatric Rheumatology International Trials Organization Classification Systems for Juvenile Idiopathic Arthritis Among Children in a Canadian Arthritis Cohort.

The aim of the Paediatric Rheumatology International Trials Organisation (PRINTO) juvenile idiopathic arthritis (JIA) classification criteria, which is still in development, is to identify homogeneous groups of JIA patients. This study was undertaken to compare International League of Associations for Rheumatology (ILAR) JIA classification criteria and PRINTO JIA classification criteria using data from the ReACCh-Out (Research in Arthritis in Canadian Children, Emphasizing Outcomes) cohort. We used clinicobiologic data recorded within 7 months of diagnosis to assign a diagnosis of JIA and identify subcategories of JIA among 1,228 patients according to the 2 JIA classification systems. We compared the proportions of patients classified and the alignment of classification categories with clinicobiologic subtypes and adult arthritis types. The PRINTO criteria classified 244 patients (19.9%) as having early-onset antinuclear antibody-positive JIA, 157 (12.8%) as having enthesitis/spondylitis-related JIA, 38 (3.1%) as having systemic JIA, and 10 (0.8%) as having rheumatoid factor-positive JIA. A total of 12% of patients were unclassifiable using the ILAR criteria, while 63.3% were unclassifiable using the PRINTO criteria (777 with other JIA and 2 with unclassified JIA). In sensitivity analyses, >50% of patients remained unclassifiable using the PRINTO criteria. Compared to the PRINTO criteria, ILAR JIA categories aligned better with clinicobiologic subtypes in 131 patients (χ2 = 44, P = 0.005, versus χ2 = 15, P = 0.07 for PRINTO), and ILAR categories aligned better with adult types of arthritis in 389 evaluable patients. Currently identified PRINTO disorders can only be used to classify a minority of JIA patients, leaving a large proportion of JIA patients with other disorders requiring further characterization. Current PRINTO JIA classification criteria do not align better with clinicobiologic subtypes or adult forms of arthritis compared with the older ILAR classification system.

Toward New Classification Criteria for Juvenile Idiopathic Arthritis: First Steps, Pediatric Rheumatology International Trials Organization International Consensus.

To revise the current juvenile idiopathic arthritis (JIA) International League of Associations for Rheumatology (ILAR) classification criteria with an evidence-based approach, using clinical and routine laboratory measures available worldwide, to identify homogeneous clinical groups and to distinguish those forms of chronic arthritis typically seen only in children from the childhood counterpart of adult diseases. The overall project consists of 4 steps. This work represents Step 1, a Delphi Web-based consensus and Step 2, an international nominal group technique (NGT) consensus conference for the new provisional Pediatric Rheumatology International Trials Organization JIA classification criteria. A future large data collection of at least 1000 new-onset JIA patients (Step 3) followed by analysis and NGT consensus (Step 4) will provide data for the evidence-based validation of the JIA classification criteria. In Step 1, three Delphi rounds of interactions were implemented to revise the 7 ILAR JIA categories. In Step 2, forty-seven questions with electronic voting were implemented to derive the new proposed criteria. Four disorders were proposed: (a) systemic JIA; (b) rheumatoid factor-positive JIA; (c) enthesitis/spondylitis-related JIA; and (d) early-onset antinuclear antibody-positive JIA. The other forms were gathered under the term "others." These will be analyzed during the prospective data collection using a list of descriptors to see whether the clustering of some of them could identify homogeneous entities. An international consensus was reached to identify different proposed homogeneous chronic disorders that fall under the historical term JIA. These preliminary criteria will be formally validated with a dedicated project.

Neutrophils in pediatric autoimmune disease.

As first immune responders, neutrophils are essential mediators of host defense, and also contribute to chronic pathologic inflammation at the crossroads of innate and adaptive immunity. In this review, we will highlight the current understanding of the role of neutrophils in pediatric rheumatology, with a focus on juvenile idiopathic arthritis (JIA) and lupus. In inflamed tissues, neutrophils extrude neutrophil extracellular traps containing autoantigen that potentially drives lupus and rheumatoid factor-positive JIA. However, the contribution of neutrophil extracellular traps to pathogenesis remains an area of intense investigation. In JIA joints, neutrophils are activated to such an extent that associated circulating levels of S100A proteins may serve as biomarkers, correlating with disease activity, predicting response to treatment and heralding flares. Beyond the effects of 'normal' activation, neutrophils in JIA and lupus display dysregulation in gene expression, subset activation, and apoptosis. The role of neutrophils in pediatric rheumatology is an understudied area, but garnering increasing attention. Although clearly implicated in JIA and lupus, the specific contributions of neutrophils to pathogenesis and the use of neutrophil activity surrogates as biomarkers require further study. Clarification of these outstanding issues will have implications for diagnosis and treatment of pediatric rheumatologic conditions.

Epstein-Barr Virus Associated Hodgkin Lymphoma in a 9-Year-Old Girl Receiving Long-Term Methotrexate Therapy for Juvenile Idiopathic Arthritis

We describe a case of Hodgkin lymphoma developing in a 9-year-old girl with polyarticular, rheumatoid factor-positive juvenile idiopathic arthritis treated with methotrexate (MTX), prednisone, and naproxen for 5 years. Pathologic and molecular analyses revealed that the Hodgkin cells contained Epstein-Barr virus and the viral DNA was monoclonal. She achieved complete remission after MTX withdrawal, chemotherapy, and radiation. To the best of my knowledge, this is the sixth report of Hodgkin lymphoma in patients with juvenile idiopathic arthritis receiving low dose MTX therapy.

A comparison of response criteria to evaluate therapeutic response in patients with juvenile idiopathic arthritis treated with methotrexate and/or anti–tumor necrosis factor α agents

There are no validated criteria to evaluate clinical response in juvenile idiopathic arthritis (JIA). The purpose of this study was to compare 4 sets of criteria (2 from the American College of Rheumatology [ACR] and 2 from the European League Against Rheumatism [EULAR]) for clinical response evaluation in JIA patients treated with methotrexate and/or anti-tumor necrosis factor alpha drugs. Seventy-five patients with JIA were evaluated at baseline and after 6 months of therapy with second-line drugs. Mean age at study onset was 12.8 years (range 2-32.9 years). Diagnoses were systemic JIA (n = 16), rheumatoid factor-positive JIA (n = 5), rheumatoid factor-negative JIA (n = 9), persistent oligoarticular JIA (n = 10), extended oligoarticular JIA (n = 33), and psoriatic arthritis (n = 2). Clinical response was evaluated with the ACR Pediatric 30 criteria and the ACR 20% response criteria (ACR20), and with the EULAR Disease Activity Score (DAS) and 28-joint DAS (DAS28). Patients with EULAR criteria responses of "good" or "moderate" were classified as responders. Responders and nonresponders according to the different criteria were then compared. For patients younger than 16 years, Cohen's kappa varied between 0.51 and 0.72, with a good-to-excellent reproducibility index for all comparisons, except for the DAS28/ACR20 comparison. The best agreement was obtained by comparing the DAS and the ACR Pediatric 30. For patients older than 16 years, the reproducibility index was good or excellent in only 2 cases, i.e., comparing the DAS and the ACR Pediatric 30 and comparing the DAS and the DAS28 (as expected). Our study shows a good agreement overall for the different criteria tested. The highest concordance was observed between the DAS and the ACR Pediatric 30, the lowest between the DAS28 and the ACR20. Our data suggest that the ACR Pediatric 30 criteria can be used also in adult patients affected by JIA, and that the original DAS can be an alternative to the ACR Pediatric 30 in both children and young adults with JIA.