The clinical and experimental treatment of Juvenile Idiopathic Arthritis.

Juvenile idiopathic arthritis (JIA) is the most common chronic rheumatic disease in children and comprises of multiple subtypes. The most relevant disease subtypes, grouped upon current insight in disease mechanisms, are nonsystemic (oligo- and polyarticular) JIA and systemic JIA (sJIA). In this review, we summarize some of the main proposed mechanisms of disease in both nonsystemic and sJIA and discuss how current therapeutic modalities target some of the pathogenic immune pathways. Chronic inflammation in nonsystemic JIA is the result of a complex interplay between effector and regulatory immune cell subsets, with adaptive immune cells, specifically T-cell subsets and antigen-presenting cells, in a central role. There is, however, also innate immune cell contribution. SJIA is nowadays recognized as an acquired chronic inflammatory disorder with striking autoinflammatory features in the first phase of the disease. Some sJIA patients develop a refractory disease course, with indications for involvement of adaptive immune pathways as well. Currently, therapeutic strategies are directed at suppressing effector mechanisms in both non-systemic and sJIA. These strategies are often not yet optimally tuned nor timed to the known active mechanisms of disease in individual patients in both non-systemic and sJIA. We discuss current treatment strategies in JIA, specifically the 'Step-up' and 'Treat to Target approach' and explore how increased insight into the biology of disease may translate into future more targeted strategies for this chronic inflammatory disease at relevant time points: preclinical disease, active disease, and clinically inactive disease.

Defining consensus opinion to develop randomised controlled trials in rare diseases using Bayesian design: An example of a proposed trial of adalimumab versus pamidronate for children with CNO/CRMO.

INTRODUCTION: Chronic nonbacterial osteomyelitis (CNO) is a rare autoinflammatory bone disorder primarily affecting children and adolescents. It can lead to chronic pain, bony deformities and fractures. The pathophysiology of CNO is incompletely understood. Scientific evidence suggests dysregulated expression of pro- and anti-inflammatory cytokines to be centrally involved. Currently, treatment is largely based on retrospective observational studies and expert opinion. Treatment usually includes nonsteroidal anti-inflammatory drugs and/or glucocorticoids, followed by a range of drugs in unresponsive cases. While randomised clinical trials are lacking, retrospective and prospective non-controlled studies suggest effectiveness of TNF inhibitors and bisphosphonates. The objective of the Bayesian consensus meeting was to quantify prior expert opinion. METHODS: Twelve international CNO experts were randomly chosen to be invited to a Bayesian prior elicitation meeting. RESULTS: Results showed that a typical new patient treated with pamidronate would have an 84% chance of improvement in their pain score relative to baseline at 26 weeks and an 83% chance on adalimumab. Experts thought there was a 50% chance that a new typical patient would record a pain score of 28mm (pamidronate) to 30mm (adalimumab) or better at 26 weeks. There was a modest trend in prior opinion to indicate an advantage of pamidronate vs adalimumab, with a 68% prior chance that pamidronate is superior to adalimumab by some margin. However, it is clear that there is considerable uncertainty about the precise relative merits of the two treatments. CONCLUSIONS: The rarity of CNO leads to challenges in conducting randomised controlled trials with sufficient power to provide a definitive outcome. We address this using a Bayesian design, and here describe the process and outcome of the elicitation exercise to establish expert prior opinion. This opinion will be tested in the planned prospective CNO study. The process for establishing expert consensus opinion in CNO will be helpful for developing studies in other rare paediatric diseases.

Mesenchymal stem cell therapy in proteoglycan induced arthritis.

OBJECTIVES: To explore the immunosuppressive effect and mechanism of action of intraperitoneal (ip) and intra-articular (ia) mesenchymal stem cell (MSC) injection in proteoglycan induced arthritis (PGIA). METHODS: MSC were administered ip or ia after establishment of arthritis. We used serial bioluminescence imaging (BLI) to trace luciferase-transfected MSC. Mice were sacrificed at different time points to examine immunomodulatory changes in blood and secondary lymphoid organs. RESULTS: Both ip and local ia MSC injection resulted in a beneficial clinical and histological effect on established PGIA. BLI showed that MSC ip and ia in arthritic mice are largely retained for several weeks in the peritoneal cavity or injected joint respectively, without signs of migration. Following MSC treatment pathogenic PG-specific IgG2a antibodies in serum decreased. The Th2 cytokine IL-4 was only upregulated in PG-stimulated lymphocytes from spleens in ip treated mice and in lymphocytes from draining lymph nodes in ia treated mice. An increase in production of IL-10 was seen with equal distribution. Although IFN-γ was also elevated, the IFN-γ/IL-4 ratio in MSC treated mice was opposite to the ratio in (untreated) active PGIA. CONCLUSIONS: MSC treatment, both ip and ia, suppresses PGIA, a non-collagen induced arthritis model. MSC are largely retained for weeks in the injection region. MSC treatment induced at the region of injection a deviation of PG-specific immune responses, suggesting a more regulatory phenotype with production of IL-4 and IL-10, but also of IFN-γ, and a systemic decrease of pathogenic PG-specific IgG2a antibodies. These findings underpin the potential of MSC treatment in resistant arthritis.

Mesenchymal stromal cells for treatment of arthritis.

Patients with refractory inflammatory arthritis can still respond favourable to autologous haematopoietic stem cell transplantation. However, this treatment has a high morbidity and even 5% mortality. Mesenchymal stromal cells (MSC), a subset of the non-haematopoietic stromal cells obtained from bone marrow, were found to have a strong immunosuppressive effect. MSC treatment is explored in many diseases like diabetes, SLE, MS and RA. This review covers all relevant literature regarding MSC treatment of inflammatory arthritis (RA and JIA). This review contains data of in vitro studies, animal studies and clinical studies. The following subjects will be discussed in detail: properties of MSC, presence of MSC in the joint, intra-articular versus intravenous route, autologous versus allogeneic, ideal source of MSC, distribution, transdifferentiation, engraftment, rejection, efficacy and toxicology. After reading this review the reader will be totally updated in this quickly evolving field of MSC therapy.

Predictors of health-related quality of life in children and adolescents with juvenile idiopathic arthritis: results from a Web-based survey.

OBJECTIVE: Children with juvenile idiopathic arthritis (JIA) experience functional impairment due to joint manifestations of the disease. The aim of our present study was to assess health-related quality of life (HRQOL) and its predictors in a group of children and adolescents with JIA. METHODS: The study sample includes all JIA patients (ages 6-18 years) who consulted a pediatric rheumatologist in Amsterdam, The Netherlands, between February 2009 and March 2010. HRQOL was measured using the Paediatric Quality of Life Inventory 4.0 (ages 6-18 years). Functional ability was measured using the Childhood Health Assessment Questionnaire, and medical and sociodemographic parameters were assessed. The study sample was compared to a Dutch youth norm population including children with other chronic health conditions. The proportion of children with JIA with an impaired HRQOL (<1 SD) was evaluated and multivariate regression analyses were performed to predict HRQOL outcome. RESULTS: Of the eligible patients, 64.1% (n = 152) participated. Both children (ages 6-12 years) and adolescents (ages 13-18 years) with JIA reported a significantly lower HRQOL in almost all domains compared to either healthy controls or children with other chronic health conditions. Approximately half of the children with JIA showed an impaired HRQOL. The main predictors of HRQOL were functional ability, pain, subjective burden of medication use, and school absence. CONCLUSION: The HRQOL is severely affected in children and adolescents with JIA. These findings underline the necessity to systematically monitor HRQOL in daily clinical practice.

[Two children with arthritis and uveitis: the clinical importance of ophthalmologic screening in children with juvenile arthritis]. / Twee kinderen met reuma en uveïtis: het klinisch belang van oogheelkundige screening bij kinderen met jeugdreuma.

Two girls, aged 8 and 13 years, with a history of arthritis presented with already advanced uveitis. Neither girl had been screened for uveitis by an ophthalmologist according to the recommendations of the American Academy of Pediatrics. Both patients had extensive posterior synechiae (adhesions between lens and iris) at their first ophthalmologic examination, which is associated with an unfavourable prognosis. At the last follow-up, the first patient had undergone seven ocular operations: five for glaucoma and two cataract surgeries. Uveitis occurs in 20% of children with juvenile idiopathic arthritis. The visual outcome of uveitis is negatively influenced by the presence of ocular complications at the first ophthalmologic examination. Ophthalmologic screening of children with juvenile idiopathic arthritis is very important because it is a common cause ofuveitis in childhood, the uveitis is usually asymptomatic, and there are sight-threatening complications. Screening is always important, even when the arthritis is in remission.