Rae S. M. Yeung

Methotrexate and corticosteroid therapy for pediatric localized scleroderma

INTRODUCTION Localized scleroderma (LS) can cause permanent disability, and there is no universally accepted effective treatment. Methotrexate (MTX) has been shown to be effective in the treatment of systemic sclerosis. OBJECTIVES To determine the efficacy and tolerability of MTX and corticosteroid therapy in patients with LS. METHODS MTX, 0.3 to 0.6 mg/kg per week, was given to 10 patients (6 girls, 4 boys; mean age, 6.8 years; mean disease duration before starting treatment, 4 years) with active LS. In addition, pulse intravenous methylprednisolone, 30 mg/kg for 3 days monthly for 3 months, was given to 9 patients at the initiation of therapy. RESULTS One patient discontinued taking MTX after a month; the remaining 9 patients responded. The median time to response was 3 months (95% CI, 1.15-4.85). One responder discontinued taking MTX after a year because of leukopenia; the LS worsened within 2 months. In another patient LS flared up after 10 months and responded to an increased dose of MTX and intravenous methylprednisolone. At the last follow-up visit, all patients who continued to receive MTX therapy had inactive skin lesions. CONCLUSION Treatment with MTX and corticosteroids appears to be effective in the treatment of LS and is generally well tolerated. A placebo-controlled study is necessary to confirm the efficacy of MTX therapy in LS.

TNF-α Is Necessary for Induction of Coronary Artery Inflammation and Aneurysm Formation in an Animal Model of Kawasaki Disease

Kawasaki disease is the most common cause of multisystem vasculitis in childhood. The resultant coronary artery lesions make Kawasaki disease the leading cause of acquired heart disease in children in the developed world. TNF-α is a pleiotropic inflammatory cytokine elevated during the acute phase of Kawasaki disease. In this study, we report rapid production of TNF-α in the peripheral immune system after disease induction in a murine model of Kawasaki disease. This immune response becomes site directed, with migration to the coronary arteries dependent on TNF-α-mediated events. Production of TNF-α in the heart is coincident with the presence of inflammatory infiltrate at the coronary arteries, which persists during development of aneurysms. More importantly, inflammation and elastin breakdown in the coronary vessels are completely eliminated in the absence of TNF-α effector functions. Mice treated with the TNF-α-blocking agent etanercept, as well as TNFRI knockout mice, are resistant to development of both coronary arteritis and coronary aneurysm formation. Taken together, TNF-α is necessary for the development of coronary artery lesions in an animal model of Kawasaki disease. These findings have important implications for potential new therapeutic interventions in children with Kawasaki disease.

Matrix metalloproteinase 9 activity leads to elastin breakdown in an animal model of Kawasaki disease.

OBJECTIVE Kawasaki disease (KD) is a multisystem vasculitis leading to damage in the coronary circulation and aneurysm formation. Because cardiac tissue from affected children is not available, investigation of the mechanisms responsible for coronary artery damage in KD requires use of a disease model. The present study was undertaken to examine, in an experimental model, the role of matrix metalloproteinase 9 (MMP-9) on coronary artery inflammation and vascular damage. METHODS C57BL/6 mice were injected with Lactobacillus casei cell wall extract to induce coronary arteritis. Hearts were isolated and assayed for MMP-9 protein expression and enzymatic activity by immunoblotting or confocal microscopy and zymography, respectively. MMP-9-deficient mice were used to examine the necessity of MMP-9 for disease development. RESULTS Localized inflammation at the coronary artery led to elastin breakdown and aneurysm formation. This occurred in the absence of smooth muscle cell apoptosis. Following disease induction, there was an increase in the amount and enzymatic activity of MMP-9, an elastolytic protease. MMP-9 was up-regulated by tumor necrosis factor alpha (TNFalpha) and produced primarily by vascular smooth muscle cells. In MMP-9-deficient animals, vascular inflammation continued to develop, but the incidence of elastin breakdown was significantly reduced. Elastin breakdown in the coronary artery was virtually eliminated by ablation of MMP-9. CONCLUSION These findings show that TNFalpha up-regulates expression of MMP-9, an important proteinase responsible for extracellular matrix breakdown, leading to coronary artery damage in this model of KD. These results have important implications regarding treatments for improving coronary outcome in affected children.

The outcomes of juvenile idiopathic arthritis in children managed with contemporary treatments: results from the ReACCh-Out cohort

Objective To describe clinical outcomes of juvenile idiopathic arthritis (JIA) in a prospective inception cohort of children managed with contemporary treatments. Methods Children newly diagnosed with JIA at 16 Canadian paediatric rheumatology centres from 2005 to 2010 were included. Kaplan–Meier survival curves for each JIA category were used to estimate probability of ever attaining an active joint count of 0, inactive disease (no active joints, no extraarticular manifestations and a physician global assessment of disease activity <10 mm), disease remission (inactive disease >12 months after discontinuing treatment) and of receiving specific treatments. Results In a cohort of 1104 children, the probabilities of attaining an active joint count of 0 exceeded 78% within 2 years in all JIA categories. The probability of attaining inactive disease exceeded 70% within 2 years in all categories, except for RF-positive polyarthritis (48%). The probability of discontinuing treatment at least once was 67% within 5 years. The probability of attaining remission within 5 years was 46–57% across JIA categories except for polyarthritis (0% RF-positive, 14% RF-negative). Initial treatment included joint injections and non-steroidal anti-inflammatory drugs for oligoarthritis, disease-modifying antirheumatic drugs (DMARDs) for polyarthritis and systemic corticosteroids for systemic JIA. Conclusions Most children with JIA managed with contemporary treatments attain inactive disease within 2 years of diagnosis and many are able to discontinue treatment. The probability of attaining remission within 5 years of diagnosis is about 50%, except for children with polyarthritis.

Early outcomes and improvement of patients with juvenile idiopathic arthritis enrolled in a Canadian multicenter inception cohort

To determine early outcomes and early improvements in a prospective inception cohort of children with juvenile idiopathic arthritis (JIA) treated with current standard therapies.

Kawasaki Disease at the Extremes of the Age Spectrum

OBJECTIVE: We sought to determine outcomes of Kawasaki disease (KD) and to explore factors associated with poor clinical outcomes for patients diagnosed outside the age range of 1 to 4 years. METHODS: A retrospective review of data for all patients seen between January 1990 and April 2007 was performed. Patients were stratified into 5 groups on the basis of age at diagnosis. RESULTS: A total of 1374 patients were identified; 61 (4%) were <6 months of age at diagnosis, 114 (8%) 6 months to <1 year, 854 (62%) 1 to 4 years, 258 (19%) 5 to 9 years, and 87 (6%) >9 years. Patients <1 year of age and those >9 years of age were more likely to have coronary artery abnormalities than were patients diagnosed between 1 and 4 years of age. Patients diagnosed between the ages of 5 and 9 years were at the lowest risk. Patients at both extremes of the age spectrum were more likely to present with <4 of the classic KD features, but only those <6 months or >5 years of age were at increased risk of being diagnosed >12 days after illness onset. Patients <6 months of age had lower albumin levels, and those <1 year of age had higher white blood cell and platelet counts, all of which are known predictors of coronary artery abnormalities. Patients >9 years of age were less likely to receive intravenous immunoglobulin treatment. CONCLUSION: Outcomes for children diagnosed with KD at either extreme of the age spectrum are suboptimal, although the associated factors are different.

Predictors of early inactive disease in a juvenile idiopathic arthritis cohort: Results of a Canadian multicenter, prospective inception cohort study

OBJECTIVE To determine early predictors of 6-month outcomes in a prospective cohort of patients with juvenile idiopathic arthritis (JIA). METHODS Patients selected were those enrolled in an inception cohort study of JIA, the Research in Arthritis in Canadian Children Emphasizing Outcomes Study, within 6 months after diagnosis. The juvenile rheumatoid arthritis core criteria set and quality of life measures were collected at enrollment and 6 months later. Outcomes evaluated included inactive disease, Juvenile Arthritis Quality of Life Questionnaire (JAQQ) scores, and Childhood Health Assessment Questionnaire (C-HAQ) scores at 6 months. RESULTS Thirty-three percent of patients had inactive disease at 6 months. Onset subtype and most baseline core criteria set measures correlated with all 3 outcomes. Relative to oligoarticular JIA, the risks of inactive disease were lower for enthesitis-related arthritis, polyarthritis rheumatoid factor (RF)-negative JIA, and polyarthritis RF-positive JIA, and were similar for psoriatic arthritis. In multiple regression analyses, the baseline JAQQ score was an independent predictor of all 3 outcomes. Other independent baseline predictors included polyarthritis RF-negative and systemic JIA for inactive disease; C-HAQ score and polyarthritis RF-positive JIA for the 6-month C-HAQ score; and active joint count, pain, and time to diagnosis for the 6-month JAQQ score. CONCLUSION Clinical measures soon after diagnosis predict short-term outcomes for patients with JIA. The JAQQ is a predictor of multiple outcomes. Time to diagnosis affects quality of life in the short term.

Repeated systematic surveillance of Kawasaki disease in Ontario from 1995 to 2006

Background:  Rising incidences of Kawasaki disease (KD) have been reported worldwide. Reported herein are the results of 4 triennial KD surveillances conducted in Ontario.

Assessment of sample collection and storage methods for multicenter immunologic research in children.

Multicenter studies involving both large and small centers separated by significant distances pose unique challenges to biological sample collection. The objective of this study was to evaluate protocols for determining inflammatory biomarkers that are cost and manpower efficient for handling blood destined for a sample repository. Tempus (Applied Biosystems) and Paxgene (Qiagen) blood collection systems were evaluated for RNA isolation. P100 tubes (BD), containing propriety stabilizers for preservation of plasma proteins, were evaluated for protein content and compared with plasma collected in conventional tubes. Blood for plasma separation was spiked with recombinant TNF-alpha and IL-2 prior to being processed and stored under various conditions. The Tempus RNA system produced a significantly greater yield of RNA at comparable quality when stored at 4 degrees C and shipped at ambient temperature than any other condition tested. The Tempus system was 20% less expensive and required approximately 40% less processing time thereby reducing costs. The P100 system preserved recombinant TNF-alpha in blood shipped at ambient temperature significantly better than conventionally collected plasma that was shipped on dry ice. There was no significant difference in IL-2 levels between the two collection methods and shipping temperatures. The Tempus RNA blood collection tubes and the P100 protein stabilization system provide the opportunity for reliable collection and ambient temperature transport of samples in multicenter studies. This cost-effective, standardized protocol for a large multicenter trial ensures the integrity of biological samples and maximizes study participation by both large and small centers.

Epidemiology and Management of Kawasaki Disease

Kawasaki disease (KD) is an acute systemic vasculitis affecting young children and is rising in incidence worldwide. It is most common in children <5 years of age, males and those of Asian ethnicity. It is an important cause of acquired heart disease in children. Standard treatment with high-dose aspirin (acetylsalicylic acid; ASA) and intravenous immune globulin (IVIG) has been shown to decrease the rate of coronary artery aneurysm development. Anti-coagulation has an important place in the management of KD, although guidance based on evidence is lacking. Treatment of refractory KD is an area under intense study and may include IVIG, corticosteroids and/or tumour necrosis factor (TNF)-α inhibitors among immunosuppressive agents. Acute complications of KD include myocarditis/KD shock syndrome and macrophage activation syndrome, which necessitate appropriate awareness in order to initiate proper management.