Infantile Takayasu: clinical features and long-term outcome.

OBJECTIVES: Takayasu arteritis (TAK) is a large-vessel vasculitis rarely reported in children and infants. Most articles on paediatric TAK have not focused on infants. We present the largest case series of infantile TAK, aiming to identify its demographic and clinical characteristics and compare them with existing data on older children. METHODS: We conducted an international multicentre retrospective cohort study. Epidemiological and clinical data were collected from patients' charts from six rheumatology centres. All patients met both the EULAR/PReS 2008 criteria and the 1990 ACR/EULAR criteria and were diagnosed with TAK at age <5 years. RESULTS: Twelve patients were included (50% female). Median age of symptom onset was 11 months, with a diagnostic delay of 4 months. The most common symptoms at presentation were hypertension, blood pressure differences between limbs, and fever. The most commonly involved arteries were the abdominal aorta and renal artery. Medications included steroids, conventional and biologic DMARDs, and other immunosuppressive therapies. Half of the patients received biologic agents, of which infliximab had the highest complete remission rate (40%). Other medications resulting in complete remission were CYC (40%) and MTX (38%). Invasive procedures were required for 58% of patients. The most common complications were cardiac (50%), stroke (42%), and serious infections (33%). No patients died. CONCLUSION: This study presents the largest series of infantile TAK. Compared with other reported series on older children, infants with TAK have more severe disease and were more likely to receive biologic agents, develop complications, and require invasive interventions.

Risk factors for haemodynamic compromise in multisystem inflammatory syndrome in children: a multicentre retrospective study.

OBJECTIVES: To identify predictors of a severe clinical course of multisystem inflammatory syndrome in children (MIS-C), as defined by the need for inotropic support. METHODS: This retrospective study included patients diagnosed with MIS-C (according to the CDC definition) in nine Israeli and one US medical centre between July 2020 and March 2021. Univariate and multivariate regression models assessed odds ratio (OR) of demographic, clinical, laboratory and imaging variables during admission and hospitalization for severe disease. RESULTS: Of 100 patients, 61 (61%) were male; mean age 9.65 (4.48) years. Sixty-five patients were hypotensive, 44 required inotropic support. Eleven patients with MIS-C fulfilled Kawasaki disease diagnostic criteria; 87 had gastrointestinal symptoms on admission. Echocardiographic evaluation showed 10 patients with acute coronary ectasia or aneurysm, and 37 with left ventricular dysfunction. In a univariate model, left ventricular dysfunction was associated with severe disease [OR 4.178 (95% CI 1.760, 9.917)], while conjunctivitis [OR 0.403 (95% CI 0.173, 0.938)] and mucosal changes [OR 0.333 (95% CI 0.119, 0.931)] at admission were protective. Laboratory markers for a severe disease course were low values of haemoglobin, platelets, albumin and potassium; and high leukocytes, neutrophils, troponin and brain natriuretic peptide. In multivariate analysis, central nervous system involvement and fever >39.5°C were associated with severe disease. Mucosal involvement showed 6.2-fold lower risk for severe disease. Low haemoglobin and platelet count, and elevated C-reactive protein and troponin levels were identified as risk factors for severe disease. CONCLUSION: Key clinical and laboratory parameters of MIS-C were identified as risk factors for severe disease, predominantly during the disease course and not at the time of admission; and may prompt close monitoring, and earlier, more aggressive treatment decisions. Patients presenting with a Kawasaki-like phenotype were less likely to require inotropic support.

Case Series of Myocarditis Following mRNA COVID Vaccine Compared to Pediatric Multisystem Inflammatory Syndrome: Multicenter Retrospective Study.

INTRODUCTION: Since the development of COVID-19 vaccines, more than 4.8 billion people have been immunized worldwide. Soon after vaccinations were initiated, reports on cases of myocarditis following the second vaccine dose emerged. This study aimed to report our experience with adolescent and young adults who developed post-COVID-19 vaccine myocarditis and to compare these patients to a cohort of patients who acquired pediatric inflammatory multisystem syndrome (PIMS/PIMS-TS) post-COVID-19 infection. METHODS: We collected reported cases of patients who developed myocarditis following COVID-19 vaccination (Pfizer mRNA BNT162b2) from all pediatric rheumatology centers in Israel and compared them to a cohort of patients with PIMS. RESULTS: Nine patients with post-vaccination myocarditis were identified and compared to 78 patients diagnosed with PIMS. All patients with post-vaccination myocarditis were males who developed symptoms following their second dose of the vaccine. Patients with post-vaccination myocarditis had a shorter duration of stay in the hospital (mean 4.4 ± 1.9 vs. 8.7 ± 4.7 days) and less myocardial dysfunction (11.1% vs. 61.5%), and all had excellent outcomes as compared to the chronic changes among 9.2% of the patients with PIMS. CONCLUSION: The clinical course of vaccine-associated myocarditis appears favorable, with resolution of the symptoms in all the patients in our cohort.

Characterizing the differences between multisystem inflammatory syndrome in children and Kawasaki disease.

To characterize the new SARS-Co-V-2 related multisystem inflammatory syndrome in children (MIS-C) among Israeli children and to compare it with Kawasaki disease (KD). We compared, in two medical centers, the clinical and laboratory characteristics of MIS-C, KD and an intermediate group, which met the case definitions of both conditions. MIS-C patients were older, were more likely to be hypotensive, to have significant gastrointestinal symptoms, lymphopenia and thrombocytopenia and to have non-coronary abnormal findings in their echocardiogram. Lymphopenia was an independent predictor of MIS-C. Most of our MIS-C patients responded promptly to corticosteroid therapy. KD incidence in both centers was similar in 2019 and 2020. Although there is clinical overlap between KD and MIS-C, these are separate entities. Lymphopenia clearly differentiates between these entities. MIS-C patients may benefit from corticosteroids as first-line therapy.

Juvenile Dermatomyositis (JDM) Complicated by Thrombotic Thrombocytopenic Purpura (TTP) and Purtscher's Retinopathy Responsive to Rituximab: Case Report and Literature Review.

Juvenile dermatomyositis (JDM) is a multisystem vasculopathy that infrequently presents with acute complications (1). We report here the case of a 12-year-old girl with JDM who developed Thrombotic Thrombocytopenic purpura (TTP) and Purtscher's retinopathy. This is the second pediatric case of JDM with TTP and Purtscher's retinopathy in the literature. The diagnosis of JDM was based on her clinical presentation (fever, myalgia, proximal muscle weakness, characteristic skin rash and elevated muscle enzymes) (2). Despite improvement of rash, fever and weakness with corticosteroids and intravenous Immunoglobulins (IVIG), the patient developed retinopathy, thrombocytopenia, hemolytic anemia, renal failure, and pulmonary edema within 1 week of initial treatment. A clinical diagnosis of TTP and Purtscher's retinopathy was made and her ADAMTS13 activity was found to be low. Regardless of aggressive treatment with pulse steroid therapy, IVIG, plasmapheresis along with multiple infusions of Fresh Frozen plasma (FFP), her condition deteriorated. In view of her worsening condition, she received one dose of Rituximab and within 48 h, her hematological and retinal involvements improved. Rituximab was given at the same dose once weekly thereafter for 4 total doses. Her disease process was halted, and retinopathy improved significantly in 48 h and continued to gradually improve over 3 weeks of maintenance therapy with cyclosporine, methotrexate, and IVIG and then stabilized. This report documents the association of TTP and Purtscher's retinopathy with JDM, emphasizing that early recognition and prompt treatment with rituximab along with the current standard of care treatment i.e., Vincristine, corticosteroids and plasmapheresis could be of potential benefit in controlling disease activity.

A high and equal prevalence of the Q703K variant in NLRP3 patients with autoinflammatory symptoms and ethnically matched controls.

OBJECTIVES: Cryopyrin associated periodic syndromes (CAPS) comprise a spectrum of autoinflammatory disorders of varying severity caused by mutations in the NLRP3 gene. The NLRP3-Q703K allele has been reported both as a functional polymorphism and as a low penetrance mutation. METHODS: To describe the clinical phenotype of subjects with the Q703K allele and to report the frequency of this allele among patients with autoinflammatory symptoms and healthy controls. To this end, a cohort of 10 ethnically-matched controls per each Q703K-carrying patient, was composed. RESULTS: Ninety patients suspected of harboring a systemic autoinflammatory disease (SAID), exclusive of FMF, were referred to our center for genotyping between 2012 and 2015. Fourteen of them (15.5%) were found to carry the Q703K allele, compared to 22 of 130 (16.9%) healthy, ethnically matched controls. CONCLUSIONS: The similar carrier rate of the NLRP3-Q703K allele among patients with manifestations of a SAID and an ethnically matched control group suggest that this variant, does not determine the clinical phenotype. This reiterates the importance of testing a control group to avoid erroneously attributing a causative role to a gene polymorphism.

Systemic adverse events following intraarticular corticosteroid injections for the treatment of juvenile idiopathic arthritis: two patients with dermatologic adverse events and review of the literature.

OBJECTIVES: Intraarticular corticosteroid injections are an important part of the treatment for juvenile idiopathic arthritis due to the ability to achieve high concentration of the medication in the affected joint, while minimizing potential systemic adverse effects. There may be some systemic absorption of corticosteroids resulting in systemic adverse events. Our aim was to demonstrate the potential of adverse events due to the systemic absorption of intraarticular corticosteroids through presentation of 2 case reports, a review of our practices and a systematic review of the literature. METHODS: We reviewed the intraarticular injections performed at our 3 centers in 2010 and 2011 for the prevalence of systemic adverse events. We searched PubMed for articles in English on systemic adverse effects of intraarticular corticosteroid injection in children, using numerous keywords, as well as review articles and textbooks on juvenile rheumatoid/idiopathic arthritis up to and including December 2011. RESULTS: We report the development of severe acneiform rashes in 2 adolescents with juvenile idiopathic arthritis following bilateral knee intraarticular injections of triamcinolone hexacetonide. The prevalence of systemic adverse events at our centers was in 4/179 (2.2%) injections, the 2 cases reported above, 1 case of insomnia in a 2-year-old child and 1 case of cushingoid features following injection of 21 joints. While in the literature there are some reports of general "Cushing-like" appearances, there are only very few reports of specific skin and other organ/system adverse effects resulting from systemic corticosteroid absorption. CONCLUSION: It is important to recognize the potential of rare adverse events that are attributable to the systemic absorption of intraarticular corticosteroids in children.

Abatacept in the treatment of polyarticular JIA: development, clinical utility, and place in therapy.

Juvenile idiopathic arthritis (JIA) is a group of chronic arthritides affecting children. The polyarthritis category, affecting five or more joints in the first six months, tends to be more aggressive, leading to a destructive joint disease with significant morbidity, disability, and costs to society. The current treatment regimen, which primarily combines methotrexate and tumor necrosis factor alpha (TNF-α) blockade, still leaves a significant group of patients with an inadequate response. Therefore, the development of new medications that act via other mechanisms of pathogenesis is necessary. T cell lymphocytes are key components in the immune reaction in JIA. Cytotoxic lymphocyte-associated antigen-4 (CTLA-4) is a potent inhibitor of the costimulation pathway necessary to activate T cells. Abatacept is a recombinant fusion protein comprising the extracellular part of human CTLA-4 connected to a modified Fc part of IgG-1. In a randomized, multinational, blinded withdrawal study in children with polyarticular JIA, abatacept was found to be effective in about 70% of the patients, including 39% of TNF-α blockade failures, with significantly fewer flares occurring during the withdrawal phase than in patients receiving placebo. Abatacept continued to show good efficacy in a three-year open-label extension study, with a beneficial effect on health-related quality of life. The safety profile of abatacept is generally good. In 2008, the US Food and Drug Administration approved abatacept for use in children over six years of age with JIA and a polyarticular course. In 2010, the European Medicines Agency gave approval for abatacept to be used in combination with methotrexate for those who fail at least one disease-modifying medication and TNF-α blockade.