Interleukin-1 Beta-Mediated Sex Differences in Kawasaki Disease Vasculitis Development and Response to Treatment.

OBJECTIVE: Kawasaki disease (KD) is the leading cause of acute vasculitis and acquired heart disease in children in developed countries. Notably, KD is more prevalent in males than females. We previously established a key role for IL (interleukin)-1 signaling in KD pathogenesis, but whether this pathway underlies the sex-based difference in susceptibility is unknown. Approach and Results: The role of IL-1 signaling was investigated in the Lactobacillus casei cell wall extract-induced experimental mouse model of KD vasculitis. Five-week-old male and female mice were injected intraperitoneally with PBS, Lactobacillus caseicell wall extract, or a combination of Lactobacillus caseicell wall extract and the IL-1 receptor antagonist Anakinra. Aortitis, coronary arteritis inflammation score and abdominal aorta dilatation, and aneurysm development were assessed. mRNA-seq (messenger RNA sequencing) analysis was performed on abdominal aorta tissue. Publicly available human transcriptomics data from patients with KD was analyzed to identify sex differences and disease-associated genes. Male mice displayed enhanced aortitis and coronary arteritis as well as increased incidence and severity of abdominal aorta dilatation and aneurysm, recapitulating the increased incidence in males that is observed in human KD. Gene expression data from patients with KD and abdominal aorta tissue of Lactobacillus caseicell wall extract-injected mice showed enhanced Il1b expression and IL-1 signaling genes in males. Although the more severe IL-1ß-mediated disease phenotype observed in male mice was ameliorated by Anakinra treatment, the milder disease phenotype in female mice failed to respond. CONCLUSIONS: IL-1ß may play a central role in mediating sex-based differences in KD, with important implications for the use of anti-IL-1ß therapies to treat male and female patients with KD.

CD8+ T Cells Contribute to the Development of Coronary Arteritis in the Lactobacillus casei Cell Wall Extract-Induced Murine Model of Kawasaki Disease.

OBJECTIVE: Kawasaki disease (KD) is the leading cause of acquired heart disease among children in developed countries. Coronary lesions in KD in humans are characterized by an increased presence of infiltrating CD3+ T cells; however, the specific contributions of the different T cell subpopulations in coronary arteritis development remain unknown. Therefore, we sought to investigate the function of CD4+ and CD8+ T cells, Treg cells, and natural killer (NK) T cells in the pathogenesis of KD. METHODS: We addressed the function of T cell subsets in KD development by using a well-established murine model of Lactobacillus casei cell wall extract (LCWE)-induced KD vasculitis. We determined which T cell subsets were required for development of KD vasculitis by using several knockout murine strains and depleting monoclonal antibodies. RESULTS: LCWE-injected mice developed coronary lesions characterized by the presence of inflammatory cell infiltrates. Frequently, this chronic inflammation resulted in complete occlusion of the coronary arteries due to luminal myofibroblast proliferation (LMP) as well as the development of coronary arteritis and aortitis. We found that CD8+ T cells, but not CD4+ T cells, NK T cells, or Treg cells, were required for development of KD vasculitis. CONCLUSION: The LCWE-induced murine model of KD vasculitis mimics many histologic features of the disease in humans, such as the presence of CD8+ T cells and LMP in coronary artery lesions as well as epicardial coronary arteritis. Moreover, CD8+ T cells functionally contribute to the development of KD vasculitis in this murine model. Therapeutic strategies targeting infiltrating CD8+ T cells might be useful in the management of KD in humans.

IL-1 Signaling Is Critically Required in Stromal Cells in Kawasaki Disease Vasculitis Mouse Model: Role of Both IL-1α and IL-1ß.

OBJECTIVE: Kawasaki disease (KD) is the most common cause of acute vasculitis and acquired cardiac disease among US children. We have previously shown that both TLR2/MyD88 and interleukin (IL)-1ß signaling are required for the Lactobacillus casei cell wall extract-induced KD vasculitis mouse model. The objectives of this study were to investigate the cellular origins of IL-1 production, the role of CD11c(+) dendritic cells and macrophages, and the relative contribution of hematopoietic and stromal cells for IL-1 responsive cells, as well the MyD88 signaling, in Lactobacillus casei cell wall extract-induced KD mouse model of vasculitis. APPROACH AND RESULTS: Using mouse knockout models and antibody depletion, we found that both IL-1α and IL-1ß were required for Lactobacillus casei cell wall extract-induced KD. Both dendritic cells and macrophages were necessary, and we found that MyD88 signaling was required in both hematopoietic and stromal cells. However, IL-1 response and signaling were critically required in nonendothelial stromal cells, but not in hematopoietic cells. CONCLUSIONS: Our results suggest that IL-1α and IL-1ß, as well as CD11c(+) dendritic cells and macrophages, are essential for the development of KD vasculitis and coronary arteritis in this mouse model. Bone marrow chimera experiments suggest that MyD88 signaling is important in both hematopoietic and stromal cells, whereas IL-1 signaling and response are required only in stromal cells, but not in endothelial cells. Determining the role of IL-1α and IL-1ß and of specific cell types in the KD vasculitis mouse model may have important implications for the design of more targeted therapies and understanding of the molecular mechanisms of KD immunopathologies.

Unrecognized Celiac Disease in Children Presenting for Rheumatology Evaluation.

BACKGROUND AND OBJECTIVES: Current clinical guidelines do not consider patients with rheumatic conditions to be at high risk for celiac disease (CD) despite numerous reported associations between the two in adults and children. The objective of this study was to evaluate the prevalence of CD among patients presenting for pediatric rheumatology evaluation. METHODS: A total of 2125 patients presenting for initial evaluation by the Division of Pediatric Rheumatology at the Hospital for Special Surgery between June 2006 and December 2013 were screened for CD as a part of the standard initial serologic evaluation. The charts of these patients were evaluated retrospectively at the end of this period. RESULTS: 36 patients (30 girls, 6 boys, mean age 9.4 ± 4.3 years, range 2-16 years) received a diagnosis of CD after serologic testing and evaluation by pediatric gastroenterology. Eight additional patients with known diagnoses of CD presented during this time period. The total prevalence of CD over this 6.5-year period was 2.0%. The most common presenting complaints among patients diagnosed with CD were myalgias, arthralgias, and rash. Less frequently, patients reported gastrointestinal complaints including abdominal pain, nausea, and diarrhea. All patients reported improvement or complete resolution of their musculoskeletal symptoms after initiation of a gluten-free diet. CONCLUSIONS: This study identified 36 new cases of CD among children presenting for rheumatology evaluation, for an overall prevalence rate of 2.0%. The majority of patients who ultimately received a diagnosis of CD presented with extraintestinal manifestations. These results underscore the importance of screening children presenting for rheumatology evaluation for CD.

A prospective study comparing infection risk and disease activity in children with juvenile idiopathic arthritis treated with and without tumor necrosis factor-alpha inhibitors.

Tumor necrosis factor-alpha (TNF-α) inhibitors are effective treatment for juvenile idiopathic arthritis (JIA) but may increase infection rates. However, active JIA may also render patients vulnerable to infection. In this study, we prospectively assessed infection rates in JIA patients treated with and without TNF-α inhibitors and correlated disease activity with infection risk. TNF-α inhibitor-naïve JIA subjects were followed up for 12 months. Subjects initiated on TNF-α inhibitors after enrollment were analyzed in the TNF group. Subjects treated without TNF-α inhibitors were analyzed in the non-TNF group. Questionnaires captured mild or severe infections. JIA disease activity by Childhood Health Assessment Questionnaire (CHAQ) disability index/pain score and physician joint count/global assessment was recorded. Twenty TNF and 36 non-TNF subjects were analyzed. The total infection rate ratio for TNF versus non-TNF group subjects was 1.14 (95% CI, 0.78-1.66; p = 0.51). The average rate of infections per month was 0.29 for TNF and 0.24 for non-TNF subjects. No severe infections or hospitalizations occurred in either group. Secondary infectious outcomes were also similar between groups. Controlling for study group, an increase in CHAQ pain score correlated with an increase in several infectious outcome measures. Our results suggest no difference in infection rates between JIA subjects treated with and without TNF-α inhibitors. Additionally, JIA disease activity may have contributed to infection risk in our cohort, irrespective of immunosuppressive therapy. Future analysis of the relationship between treatment regimens, disease activity, and infection rates may help to further delineate predictors of infection risk in JIA patients.

Health related quality of life measure in systemic pediatric rheumatic diseases and its translation to different languages: an international collaboration.

BACKGROUND: Rheumatic diseases in children are associated with significant morbidity and poor health-related quality of life (HRQOL). There is no health-related quality of life (HRQOL) scale available specifically for children with less common rheumatic diseases. These diseases share several features with systemic lupus erythematosus (SLE) such as their chronic episodic nature, multi-systemic involvement, and the need for immunosuppressive medications. HRQOL scale developed for pediatric SLE will likely be applicable to children with systemic inflammatory diseases. FINDINGS: We adapted Simple Measure of Impact of Lupus Erythematosus in Youngsters (SMILEY©) to Simple Measure of Impact of Illness in Youngsters (SMILY©-Illness) and had it reviewed by pediatric rheumatologists for its appropriateness and cultural suitability. We tested SMILY©-Illness in patients with inflammatory rheumatic diseases and then translated it into 28 languages. Nineteen children (79% female, n=15) and 17 parents participated. The mean age was 12±4 years, with median disease duration of 21 months (1-172 months). We translated SMILY©-Illness into the following 28 languages: Danish, Dutch, French (France), English (UK), German (Germany), German (Austria), German (Switzerland), Hebrew, Italian, Portuguese (Brazil), Slovene, Spanish (USA and Puerto Rico), Spanish (Spain), Spanish (Argentina), Spanish (Mexico), Spanish (Venezuela), Turkish, Afrikaans, Arabic (Saudi Arabia), Arabic (Egypt), Czech, Greek, Hindi, Hungarian, Japanese, Romanian, Serbian and Xhosa. CONCLUSION: SMILY©-Illness is a brief, easy to administer and score HRQOL scale for children with systemic rheumatic diseases. It is suitable for use across different age groups and literacy levels. SMILY©-Illness with its available translations may be used as useful adjuncts to clinical practice and research.

Marked acceleration of atherosclerosis after Lactobacillus casei-induced coronary arteritis in a mouse model of Kawasaki disease.

OBJECTIVE: The purpose of this study was to investigate whether Lactobacillus casei cell wall extract-induced Kawasaki disease (KD) accelerates atherosclerosis in hypercholesterolemic mice. Method and Results- Apolipoprotein E knockout or low-density lipoprotein receptor knockout mice were injected with Lactobacillus casei cell wall extract (KD mice) or PBS, fed high-fat diet for 8 weeks, and atherosclerotic lesions in aortic sinuses, arch (AC), and whole aorta were assessed. KD mice had larger, more complex aortic lesions with abundant collagen, and both extracellular and intracellular lipid and foam cells, compared with lesions in control mice despite similar cholesterol levels. Both apolipoprotein E knockout KD and low-density lipoprotein receptor knockout KD mice showed dramatic acceleration in atherosclerosis versus controls, with increases in en face aortic atherosclerosis and plaque size in both the aortic sinuses and AC plaques. Accelerated atherosclerosis was associated with increased circulating interleukin-12p40, interferon-γ, tumor necrosis factor-α, and increased macrophage, dendritic cell, and T-cell recruitment in lesions. Furthermore, daily injections of the interleukin-1Ra, which inhibits Lactobacillus casei cell wall extract-induced KD vasculitis, prevented the acceleration of atherosclerosis. CONCLUSIONS: Our results suggest an important pathophysiologic link between coronary arteritis/vasculitis in the KD mouse model and subsequent atherosclerotic acceleration, supporting the concept that a similar relation may also be present in KD patients. These results also suggest that KD in childhood may predispose to accelerated and early atherosclerosis as adults.

Interleukin-1ß is crucial for the induction of coronary artery inflammation in a mouse model of Kawasaki disease.

BACKGROUND: Kawasaki disease (KD) is the most common cause of acute vasculitis and acquired cardiac disease in US children. Untreated, children may develop coronary artery aneurysms, myocardial infarction, and sudden death as a result of the illness. Up to a third of KD patients fail to respond to intravenous immunoglobulin, the standard therapy, and alternative treatments are being investigated. Genetic studies have indicated a possible role for interleukin (IL)-1ß in KD. We therefore explored the role of IL-1ß in a murine model of KD. METHODS AND RESULTS: Using an established mouse model of KD that involves injection of Lactobacillus casei cell wall extract (LCWE), we investigated the role of IL-1ß and caspase-1 (activated by the inflammasome and required for IL-1ß maturation) in coronary arteritis and evaluated the efficacy of IL-1 receptor antagonist as a potential treatment. LCWE-induced IL-1ß maturation and secretion were dependent on the NLRP3 inflammasome in macrophages. Both caspase-1-deficient and IL-1 receptor-deficient mice were protected from LCWE-induced coronary lesions. Injection of recombinant IL-1ß into caspase-1-deficient mice restored the ability of LCWE to cause coronary lesions in response to LCWE. Furthermore, daily injections of the IL-1 receptor antagonist prevented LCWE-mediated coronary lesions up to 3 days after LCWE injection. CONCLUSIONS: Our results strongly suggest that caspase-1 and IL-1ß play critical roles in the development of coronary lesions in this KD mouse model, blocked by IL-1 receptor antagonist. Therefore, anti-IL-1ß treatment strategies may constitute an effective, more targeted treatment of KD to prevent coronary lesions.

Children with partial IgA deficiency: clinical characteristics observed in the pediatric rheumatology clinic.

Literature is lacking on partial IgA deficiency. In this study, the authors propose to describe the clinical manifestations of patients with partial IgA deficiency. Methods. The authors conducted a retrospective chart review of 13 patients with partial IgA deficiency followed at the pediatric rheumatology clinic at Robert Wood Johnson Medical School. They looked for the presence of rashes, joint pain, joint swelling, and morning stiffness. The authors also examined charts for a history of frequent infections, allergies, and the presence of elevated antinuclear antibody. Results. Eleven out of the 13 patients complained of joint pain, joint swelling, or morning stiffness. Six patients carried a diagnosis of a definitive rheumatic disease. Four patients suffered from frequent infections and 2 patients reported allergies. Conclusion. Partial IgA deficiency appears to be associated with rheumatic diseases and complaints of joint pain, joint swelling, and morning stiffness. A larger study is needed to confirm these results.

Development of a vision-related quality of life instrument for children ages 8-18 years for use in juvenile idiopathic arthritis-associated uveitis.

OBJECTIVE: To determine the validity and reliability of a novel questionnaire to measure vision-related quality of life (VRQOL) in children ages 8-18 years for use in juvenile idiopathic arthritis (JIA)-associated uveitis: the Effects of Youngsters' Eyesight on Quality of Life (EYE-Q). METHODS: Several steps validated the EYE-Q. We interviewed experts and children on how vision affects a child's activities. We developed new items and selected relevant items from existing instruments. We administered initial versions of the EYE-Q to normal-sighted children and those with JIA-associated uveitis. For this study, children with various (or no) ocular conditions were recruited from a clinical population. Visual acuity and contrast sensitivity were performed, and the EYE-Q and Pediatric Quality of Life Inventory (PedsQL) were administered. The EYE-Q was repeated 10 days later. Patients, parents, and physicians rated vision severity. RESULTS: Of 120 patients, 48% were female, 46.7% had no visual impairment, and 53.3% had bilateral eye involvement. The mean age was 11.3 years. There were significant differences in the measures based on visual acuity (P < 0.001). Children with more severe visual acuity and bilateral eye involvement had worse EYE-Q scores (P < 0.001). There were significant associations between the EYE-Q and PedsQL (r = 0.375), repeat EYE-Q (r = 0.864), and clinical measures of ocular disease (r = -0.620). CONCLUSIONS: Our study provides evidence of the validity and reliability of the EYE-Q in the measurement of VRQOL. The EYE-Q may complement clinical measures of visual impairment and overall QOL and become an important tool in the assessment of QOL in JIA-associated uveitis.

Diagnosis of the mucopolysaccharidoses.

The mucopolysaccharidoses (MPSs) often present a diagnostic challenge, particularly for patients who have more slowly progressive disease phenotypes, as early disease manifestations can be subtle or non-specific. However, certain types of bone and joint involvement should always prompt consideration of an MPS diagnosis, such as early joint involvement without classic inflammatory features or erosive bone lesions, claw hand, spinal deformities or dysostosis multiplex. All such patients should be referred to a geneticist or metabolic specialist for diagnostic evaluation. The earlier the diagnosis is made, the better the potential outcome of treatment. Each type of MPS is associated both with deficient activity of a specific lysosomal enzyme that degrades specific glycosaminoglycans (GAGs) and with abnormalities in urinary GAG excretion. MPS patients usually excrete excess GAG in urine and/or have different relative proportions of types of GAG in urine as compared with age-matched normal subjects. Although urinary GAG analyses (both quantitative and qualitative) can suggest the most likely type of MPS, diagnosis must be confirmed by enzyme assay. Multiple assays may be necessary to identify the disease subtype. Correct identification of the MPS type is essential to guide treatment and management decisions.

Neutral lipid storage disease with subclinical myopathy due to a retrotransposal insertion in the PNPLA2 gene.

An 18-year-old girl referred to a rheumatologist with malar flush and Gottran papules was found to have a markedly elevated serum CK. She was a good student and an avid ballet dancer. A muscle biopsy showed massive triglyceride storage, which was also found in peripheral blood granulocytes (Jordan anomaly) and cultured skin fibroblasts. Assessment using computerized dynamometry and cycle ergometry showed normal strength and muscle energetics, but proton spectroscopy revealed severe triglyceride accumulation in both skeletal and cardiac muscle. Sequencing of PNPLA2, the gene responsible for neutral lipid storage disease with myopathy (NLSDM), revealed a retrotransposal insertion of about 1.8kb in exon 3 that abrogates transcription of PNPLA2. The sequences of CGI-58, the gene responsible for Chanarin-Dorfman syndrome (CDS), another multisystem triglyceride storage disease, and of two genes encoding lipid droplets-associated proteins, perilipin A and adipophilin, were normal. This case shows that NLSDM can be a transposon-associated disease and that massive lipid storage in muscle can present as asymptomatic hyperCKemia.

The importance of visual function in the quality of life of children with uveitis.

BACKGROUND: Studies of quality of life (QOL) in children with juvenile idiopathic arthritis (JIA) have focused on changes in musculoskeletal function secondary to arthritis. The role of visual functionality as a result of JIA-associated uveitis and its complications has not been examined. We evaluated the individual impact of physical and visual disability on QOL in children with and without uveitis. METHODS: We administered patient-based questionnaires that measured visual function, physical function, and overall QOL to 27 children with JIA or idiopathic uveitis. Demographic data, assessed joint involvement, and reviewed medical records were recorded. Groups with and without uveitis were compared for differences in arthritis and uveitis disease characteristics with use of the Wilcoxon-Mann-Whitney, chi2, and Fisher exact tests. Associations between physical or visual function, and overall QOL were measured with use of Pearson's correlation coefficient. RESULTS: Of 27 patients, 85.2% had had arthritis and 51.9% had had uveitis. The group without uveitis had increased morning stiffness (p = 0.036). Patients with uveitis reported more eye redness (p = 0.033) and photophobia (p = 0.013) than those without uveitis. We observed moderate associations between overall QOL and visual function in the uveitis group (r = -0.579) and overall QOL and physical function in the nonuveitis group (r = -0.562). CONCLUSIONS: This study demonstrates that visual impairment is an important component of QOL in children with uveitis. It suggests that QOL studies should incorporate both visual and physical function measures in their analyses, especially because many children with JIA also suffer from uveitis and visual impairment.

Morphea, diabetes mellitus type I, and celiac disease: case report and review of the literature.

An 11-year-old girl with a history of diabetes mellitus type I and celiac disease presented with multiple, depressed patches of purple-brown skin on the right lower extremity and central back, with histopathologic features of early morphea. Though morphea may coexist with other autoimmune diseases, its presentation with both diabetes mellitus type I and celiac disease has not yet been described.

Rituximab for severe refractory pediatric Wegener granulomatosis.

We describe a case of pediatric Wegener granulomatosis initially treated with cyclophosphamide and oral corticosteroids resulting in remission for 5 years. Of note in this case is relapse with severe pulmonary disease treated with multiple regimens, all unsuccessful. Patient achieved remission with rituximab infusion therapy. This demonstrates how rituximab may be beneficial for childhood-onset Wegener granulomatosis unresponsive to conventional therapy. The case is followed by a review of the current treatment options.