A score for predicting colchicine resistance at the time of diagnosis in familial Mediterranean fever: data from the TURPAID registry.

OBJECTIVES: Colchicine forms the mainstay of treatment in FMF. Approximately 5-10% of FMF patients are colchicine resistant and require anti-IL-1 drugs. We aimed to compare the characteristics of colchicine-resistant and colchicine-responsive patients and to develop a score for predicting colchicine resistance at the time of FMF diagnosis. METHODS: FMF patients (0-18 years) enrolled in the Turkish Paediatric Autoinflammatory Diseases (TURPAID) registry were included. The predictive score for colchicine resistance was developed by using univariate/multivariate regression and receiver operating characteristics analyses. RESULTS: A total of 3445 FMF patients [256 (7.4%) colchicine-resistant and 3189 colchicine-responsive) were included (female:male ratio 1.02; median age at diagnosis 67.4 months). Colchicine-resistant patients had longer, more frequent attacks and were younger at symptom onset and diagnosis (P < 0.05). Fever, erysipelas-like erythema, arthralgia, arthritis, myalgia, abdominal pain, diarrhoea, chest pain, comorbidities, parental consanguinity and homozygosity/compound heterozygosity for exon 10 MEFV mutations were significantly more prevalent among colchicine-resistant than colchicine-responsive patients (P < 0.05). Multivariate logistic regression analysis in the training cohort (n = 2684) showed that age at symptom onset, attack frequency, arthritis, chest pain and having two exon 10 mutations were the strongest predictors of colchicine resistance. The score including these items had a sensitivity of 81.3% and a specificity of 49.1%. In the validation cohort (n = 671), its sensitivity was 93.5% and specificity was 53.8%. CONCLUSION: We developed a clinician-friendly and practical predictive score that could help us identify FMF patients with a greater risk of colchicine resistance and tailor disease management individually at the time of diagnosis.

Risk of flare in juvenile idiopathic arthritis: Is it related to the methotrexate treatment strategy or patient characteristics?

Objectives: The study aimed to determine the factors that increase the risk of disease flare in patients with juvenile idiopathic arthritis who stopped methotrexate (MTX) monotherapy following inactive disease (ID). Patients and methods: In the retrospective study, files of all juvenile idiopathic arthritis cases between April 1992 and June 2022 were examined. Patients who stopped MTX monotherapy following ID were evaluated. Patients with disease flare and persistent ID were compared. Juvenile idiopathic arthritis subgroup, age of symptom onset, autoantibodies, acute phase reactants, MTX method of use, and withdrawal strategy were recorded. Systemic juvenile idiopathic arthritis patients were excluded from the study due to different clinical symptoms, diagnosis, and treatment methods. Results: Files of 1,036 patients were evaluated, and 107 patients (88 females, 19 males; mean age: 5.9±4.2 years; range, 0.8-16.5 years) were included in the study. The median age at symptom onset was 4.8 (interquartile range [IQR]: 2-7.6) years. In terms of juvenile idiopathic arthritis subgroups, 52 (48.6%) had oligoarticular juvenile idiopathic arthritis, 43 (40.2%) had polyarticular juvenile idiopathic arthritis, and 12 (11.2%) had juvenile psoriatic arthritis. The patients reached ID in nine (IQR: 4.8-17.7) months after starting MTX, and MTX treatment was discontinued after one (IQR: 0.7-1.3) year following ID. The disease flare developed in 59 (55%) of the cases. The ID continued in 48 (45%) patients. In multivariate analysis, the risk of flare was associated with younger symptom onset (odds ratio [OR]=2.2, p=0.006), antinuclear antibody positivity (OR=1.6, p=0.03), higher erythrocyte sedimentation rate (OR=1.01, p=0.04), and C-reactive protein (OR=1, p=0.02) at the MTX onset. No difference was observed between the two groups regarding MTX dose, route of administration, prior and concomitant treatments, time to reach ID, and time and method of MTX discontinuation. Conclusion: In this study, the risk of flare was associated with patient's characteristics, rather than the administration and discontinuation method of MTX.

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

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.