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author:("kis, Wietse")
1.  Long‐term outcome of juvenile idiopathic arthritis following a placebo‐controlled trial: sustained benefits of early sulfasalazine treatment 
Annals of the Rheumatic Diseases  2007;66(11):1518-1524.
A previous 24‐week randomised trial demonstrated that sulfasalazine (SSZ) treatment was superior to placebo (PLAC) in suppressing disease activity in patients with oligo‐ and polyarticular onset juvenile idiopathic arthritis (JIA). The current study determines the long‐term outcome of the trial participants and evaluates whether the benefits of SSZ allocation are sustained over time.
Between 2001 and 2003, 32 SSZ and 29 PLAC patients (90% of all patients) were prospectively examined clinically and by chart review, median 9 years (range 7 to 10) after trial inclusion. In the follow‐up assessment, variables of the American College of Rheumatology Pediatric 30 (ACR Pedi 30) criteria were collected. The assessor was blinded to trial treatment allocation.
After the trial, patients had been routinely followed in rheumatology referral centres, and treated at the discretion of the attending physician. Almost all patients continued or started disease‐modifying antirheumatic drugs (DMARDs) (SSZ 91%, PLAC 93%; SSZ treatment in about 80%). DMARD treatment appeared less intensive in the SSZ group as evidenced by a significantly shorter duration of SSZ use (median 2.5 vs 5.2 years; p = 0.02) and a trend towards less use of methotrexate and other DMARDs. More than one‐third of the patients reported long periods of non‐compliance with DMARD treatment in both groups.
At follow‐up, 74% of the patients had active joints, and 30% showed active polyarthritis. Almost all outcome scores were better for SSZ compared with PLAC patients. Differences (often exceeding 50%) were significant for the number of active joints, patients' overall well‐being, number of patients with episodes of clinical remission off medication (CROM) and duration of these episodes, patients in CROM and ACR Pedi 30 response at follow‐up. Additional exploratory analyses performed to detect potential confounders related to patient characteristics or follow‐up treatment showed that DMARD treatment compliance was positively correlated with an ACR Pedi 30 response (odds ratio 3.8, 95% confidence interval (CI) 1.1 to 13.4; p = 0.03). Adjusted for compliance, an SSZ patient was 4.2 times as likely as a PLAC patient to be an ACR Pedi 30 responder at follow‐up (95% CI 1.3 to 14.3; p = 0.02).
This follow‐up study shows that effective suppression of disease activity by SSZ treatment early in active disease in JIA patients has beneficial effects that persist for many years. Given these results, compliance with DMARD treatment deserves serious attention.
PMCID: PMC2111611  PMID: 17491099
2.  Safety of measles, mumps and rubella vaccination in juvenile idiopathic arthritis 
Annals of the Rheumatic Diseases  2007;66(10):1384-1387.
To assess the effect of measles, mumps and rubella (MMR) vaccination on disease activity in children with juvenile idiopathic arthritis (JIA).
A retrospective observational multicentre cohort study was performed in 314 patients with JIA, born between 1989 and 1996. Disease activity and medication use were compared during the period of 6 months before vaccination versus 6 months after vaccination. Disease activity was measured by joint counts, the Physician's global assessment scale and erythrocyte sedimentation rate. Next, we compared disease activity in patients vaccinated between 8 and 9 years of age with the activity in patients who had not been vaccinated at this time (who received MMR between the ages of 9 and 10 years).
No increase in disease activity or medication use was seen in the 6 months after MMR vaccination (n = 207), including in patients using methotrexate (n = 49). No overt measles infections were noted. When disease activity in vaccinated patients (n = 108) was compared with activity in those not yet vaccinated (n = 86), there were no significant differences.
The MMR booster vaccination does not seem to aggravate disease activity in JIA. This indicates that the most patients with JIA can be vaccinated safely with the MMR vaccine. A prospective study is recommended.
PMCID: PMC1994321  PMID: 17284544
measles; mumps and rubella vaccination; juvenile idiopathic arthritis; methotrexate; disease activity parameters; flares
3.  Systemic JIA: New Developments in the Understanding of the Pathophysiology and Therapy 
Systemic juvenile idiopathic arthritis (sJIA) is a rare, systemic inflammatory disease classified as a subtype of JIA. Besides arthritis, it is characterised by systemic features like spiking fever, skin rash, hepatosplenomegaly or serositis. It is becoming clear now that abnormalities in the innate immunity (cytokines like IL-1, IL-6 and IL-18, and neutrophils and monocytes/macrophages rather than lymphocytes) play a major role in the pathogenesis of sJIA, distinguishing sJIA from other JIA-subtypes. Another distinctive feature of sJIA is its strong association with macrophage activation syndrome (MAS). Based on this, consensus is emerging that sJIA should be viewed as an auto-inflammatory syndrome rather than a ‘classic’ autoimmune disease.
As a consequence of the progression in understanding the underlying mechanisms of sJIA, major changes in the management are evolving. Sofar, treatment has been based on glucocorticosteroids in combination with disease modifying drugs like methotrexate. Recently, remarkable improvement has been observed with IL-1 and IL-6 targeted therapies. These therapies might also change the long term outcome of this disease. However, controlled trials set up in international collaboration are needed to determine the optimal treatment strategies for all sJIA patients.
PMCID: PMC2774820  PMID: 19853830
systemic juvenile idiopathic arthritis; innate immunity; myeloid related proteins (MRP´s); IL-1; IL-6; Macrophage Activation Syndrome (MAS)
4.  Blood and synovial fluid cytokine signatures in patients with juvenile idiopathic arthritis: a cross‐sectional study 
Annals of the Rheumatic Diseases  2006;66(5):589-598.
Juvenile idiopathic arthritis (JIA) consists of a heterogeneous group of disorders with, for the most part, an unknown immunopathogenesis. Although onset and disease course differ, the subtypes of JIA share the occurrence of chronic inflammation of the joints, with infiltrations of immunocompetent cells that secrete inflammatory mediators.
To identify a panel of cytokines specifically related to the inflammatory process in JIA.
Using a new technology, the multiplex immunoassay, 30 cytokines were measured in plasma of 65 patients with JIA , of which 34 were paired with synovial fluid. These data were compared with plasma of 20 healthy controls and 9 patients with type I diabetes, a chronic inflammatory disease.
Patients with JIA had, irrespective of their subclassification, significantly higher levels of tumour necrosis factor α, macrophage inhibitory factor (MIF), CCL2, CCL3, CCL11, CCL22 and CXCL9 in plasma than controls. In paired plasma and synovial fluid samples of patients with JIA, significantly higher levels of interleukin (IL)6, IL15, CCL2, CCL3, CXCL8, CXCL9 and CXCL10 were present in synovial fluid. Cluster analysis in all patients with JIA revealed a predominant pro‐inflammatory cytokine cluster during active disease and a regulatory/anti‐inflammatory‐related cytokine cluster during remission. Whether a discrimination profile of various cytokines could help in the determination of disease classification was tested.
It is suggested that several cytokines (IL18, MIF, CCL2, CCL3, CCL11, CXCL9 and CXCL10) may correspond to the activation status during inflammation in JIA and could be instrumental in monitoring disease activity and outcomes of (new) immunotherapies.
PMCID: PMC1954617  PMID: 17170049
5.  Novel self-epitopes derived from aggrecan, fibrillin, and matrix metalloproteinase-3 drive distinct autoreactive T-cell responses in juvenile idiopathic arthritis and in health 
Juvenile idiopathic arthritis (JIA) is a heterogeneous autoimmune disease characterized by chronic joint inflammation. Knowing which antigens drive the autoreactive T-cell response in JIA is crucial for the understanding of disease pathogenesis and additionally may provide targets for antigen-specific immune therapy. In this study, we tested 9 self-peptides derived from joint-related autoantigens for T-cell recognition (T-cell proliferative responses and cytokine production) in 36 JIA patients and 15 healthy controls. Positive T-cell proliferative responses (stimulation index ≥2) to one or more peptides were detected in peripheral blood mononuclear cells (PBMC) of 69% of JIA patients irrespective of major histocompatibility complex (MHC) genotype. The peptides derived from aggrecan, fibrillin, and matrix metalloproteinase (MMP)-3 yielded the highest frequency of T-cell proliferative responses in JIA patients. In both the oligoarticular and polyarticular subtypes of JIA, the aggrecan peptide induced T-cell proliferative responses that were inversely related with disease duration. The fibrillin peptide, to our knowledge, is the first identified autoantigen that is primarily recognized in polyarticular JIA patients. Finally, the epitope derived from MMP-3 elicited immune responses in both subtypes of JIA and in healthy controls. Cytokine production in short-term peptide-specific T-cell lines revealed production of interferon-γ (aggrecan/MMP-3) and interleukin (IL)-17 (aggrecan) and inhibition of IL-10 production (aggrecan). Here, we have identified a triplet of self-epitopes, each with distinct patterns of T-cell recognition in JIA patients. Additional experiments need to be performed to explore their qualities and role in disease pathogenesis in further detail.
PMCID: PMC1794523  PMID: 17129378
6.  Simultaneous Detection of 15 Human Cytokines in a Single Sample of Stimulated Peripheral Blood Mononuclear Cells 
Cytokines secreted by cells of the immune system can alter the behavior and properties of immune or other cells. At a site of inflammation, sets of cytokines interact with immune cells, and their combined effect is often more important than the function of one isolated component. Conventional techniques, such as enzyme-linked immunosorbent assays, generally require large quantities of cells to characterize a complete cytokine profile of activated lymphocytes. The Bio-Plex system from Bio-Rad Laboratories combines the principle of a sandwich immunoassay with the Luminex fluorescent-bead-based technology. We developed a multiplex cytokine assay to detect different cytokines simultaneously in culture supernatant of human peripheral blood mononuclear cells stimulated with antigen and with mitogen. Fifteen human cytokines (interleukin 1α [IL-1α], IL-1β, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12p70, IL-13, IL-15, IL-17, IL-18, gamma interferon, and tumor necrosis factor alpha) were validated with a panel of healthy individuals, rheumatoid arthritis patients, and juvenile idiopathic arthritis patients. Comparing the multiplex assay with a regular enzyme-linked immunosorbent assay technique with this donor panel resulted in correlation coefficients for all cytokines ranging from 0.75 to 0.99. Intra-assay variance proved to be less then 10%, whereas interassay variability ranged between 10 and 22%. This multiplex system proved to be a powerful tool in the quantitation of cytokines. It will provide a more complete picture in differences between activated lymphocyte cytokine profiles from healthy individuals and those from patients with chronic inflammatory diseases.
PMCID: PMC145264  PMID: 12522051

Results 1-6 (6)