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

• Main Authors: Semanur Ozdel (Author), Hafize Emine Sönmez (Author), Şengül Çağlayan (Author), Özlem Akgün (Author), Tuncay Aydın (Author), Özge Baba (Author), İlknur Bağrul (Author), Gülçin Otar Yener (Author), Kübra Öztürk (Author), Ferhat Demir (Author), Deniz Gezgin Yıldırım (Author), Şerife Gül Karadağ (Author), Esra Bağlan (Author), Mustafa Çakan (Author), Mukaddes Kalyoncu (Author), Balahan Bora Makay (Author), Şevket Erbil Ünsal (Author), Sevcan Bakkaloğlu (Author), Mehmet Bülbül (Author), Betül Sözeri (Author), Nuray Aktay Ayaz (Author)
• Format: Book
• Published: BMC, 2023-07-01T00:00:00Z.
• Subjects: article
• Online Access: Connect to this object online.
• Notes: 10.1186/s12969-023-00860-5; 1546-0096
• Keywords: Juvenile; Idiopathic; Arthritis; Rheumatoid factor; Pediatrics; RJ1-570; Diseases of the musculoskeletal system; RC925-935
• Source: Pediatric Rheumatology Online Journal, Vol 21, Iss 1, Pp 1-7 (2023)

Abstract Objective Rheumatoid 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. Methods This 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. Results The 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. Conclusion During 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.