Juvenile idiopathic arthritis with systemic onset with inflammatory bone lesions: two case reports of patients successfully treated with canakinumab and experience gained from literature.

Non-bacterial osteomyelitis (NBO) is a rare chronic inflammatory bone disease related to immune system dysregulation. This disease belongs to a family of autoinflammatory diseases. It often coexists with other TNF-α-mediated immune-mediated diseases such as juvenile idiopathic arthritis (JIA) and inflammatory bowel diseases. Previously, interleukin-1-driven inflammation was described predominantly in monogenic cases of NBO, such as DIRA syndrome or Majeed syndrome. However, the association between NBO and JIA with systemic onset (soJIA) has not been described yet. Herein, we describe the cases of two patients with soJIA with inflammatory bone lesions wherein canakinumab (anti-interleukin-1ß antibodies) caused remission. Case descriptions: Patient 1-A 6-month-old boy with typical soJIA suffered a destruction of the 7th to 9th ribs and the left pubic bone. Antibiotics, IVIG, and cyclosporine proved ineffective. Corticosteroids were effective, but due to the factor of corticosteroid dependence, which has some disadvantages, canakinumab with a dosage of 4 mg/kg was initiated every 4 weeks, which completely controlled the disease and allowed to taper corticosteroids.Patient 2-A 2-year-old girl developed chronic non-bacterial osteomyelitis of the 5th rib 2 months after taking corticosteroids prescribed for typical soJIA. She underwent surgical debridement removal, and several courses of antibiotics proved ineffective. She developed macrophage activation syndrome, following which anakinra was prescribed, which resulted in only temporary improvement. Therefore, this drug was switched to canakinumab, which caused corticosteroid-free remission. Conclusion: This is the first description of a rare association of soJIA with inflammatory bone lesions with the proven efficacy of IL-1 blockade. The association of two autoinflammatory conditions should indicate IL-1-driven mechanisms and a possible genetic basis. Follow-up genetic and functional studies are required to better understand the pathogenesis of such overlapping diseases.

Predictors of the response to etanercept in patients with juvenile idiopathic arthritis without systemic manifestations within 12 months: results of an open-label, prospective study conducted at the National Scientific and Practical Center of Children's Health, Russia.

BACKGROUND: The aim of this study was to investigate the efficacy of etanercept treatment and to identify predictors of response to therapy within 12 months in patients with juvenile idiopathic arthritis (JIA) without systemic manifestations. METHODS: A total of 197 juvenile patients were enrolled in this study. Response to therapy was assessed using the ACRPedi 30/50/70/90 criteria, the Wallace criteria, and the Juvenile Arthritis Disease Activity Score 71 (JADAS-71). Univariate and multivariate logistic regression analyses were performed to identify potential baseline factors associated with treatment response in different JIA categories. RESULTS: One year after treatment initiation, 179 (90.9%) patients achieved ACRPedi30; 177 (89.8%) patients achieved ACRPedi50; 168 (85.3%) patients achieved ACRPedi70; and 135 (68.5%) patients achieved ACRPedi90 response. A total of 132 (67.0%) and 92 (46.7%) patients achieved inactive disease according to the Wallace criteria and the JADAS-71 cut-off point, respectively. Excellent response (achieving ACRPedi90 and clinically inactive disease according both to the Wallace criteria and the JADAS71 cut-off point) was associated with persistent oligoarticular JIA category, shorter disease duration before the start of etanercept, a lower number of DMARDs used before the introduction of etanercept, a lower number of joints with limited motion, and lower C-reactive protein at baseline. Poor response (failure to achieve ACR 70 or active disease according to both the Wallace criteria and JADAS71 even when ACR 70 was achieved) was associated with the polyarticular or enthesitis-related JIA categories, higher disease duration before the start of etanercept, and older age at disease onset. CONCLUSION: Almost half (45.7%) of the patients who initiated etanercept treatment achieved an excellent response (inactive disease and ACRPedi90) after 1 year. What may be novel is our finding that the response to etanercept therapy was strongly associated with the JIA category. The response to etanercept therapy was also associated with the disease duration before the start of etanercept treatment.

Efficacy and safety of repeat courses of rituximab treatment in patients with severe refractory juvenile idiopathic arthritis.

Treatment of severe juvenile idiopathic arthritis (JIA) represents a serious challenge. This study investigates the efficacy and safety of repeat courses of rituximab in patients with different forms of JIA refractory to infliximab and standard immunosuppressive therapy. Patients (n = 55; age 2.3-17.0 years) with severe polyarticular and systemic JIA (International League of Association for Rheumatology diagnostic criteria) received rituximab (one intravenous infusion/week for 4 weeks, 375 mg/m(2) per dose). Efficacy was assessed using the American College of Rheumatology Pediatric (ACR Pedi) criteria. The primary endpoint was an ACR Pedi 30 response at week 24. At week 24, ACR Pedi 30, 50, and 70 responses were achieved by 98%, 50%, and 40% of patients, respectively. By week 96, ACR Pedi 30, 50, and 70 responses were achieved by 98%, 93%, and 93% of 25 patients, respectively. Remission was recorded in 25%, 52%, 75%, and 98% of patients following the first (24 weeks), second (48 weeks), third (72 weeks), and fourth (96 weeks) courses of rituximab, respectively. Rituximab treatment significantly reduced the number of systemic manifestations at week 12 and also enabled 52% of patients to achieve remission of arthritis by week 48. This study supports the efficacy of rituximab in patients with severe forms of JIA, refractory to several prior agents.