Clonally expanded PD-1-expressing T cells are enriched in synovial fluid of juvenile idiopathic arthritis patients.

Juvenile idiopathic arthritis (JIA) is the most common chronic rheumatic condition in childhood. The disease etiology remains largely unknown; however, a key role in JIA pathogenesis is surely mediated by T cells. T-lymphocytes activity is controlled via signals, known as immune checkpoints. Delivering an inhibitory signal or blocking a stimulatory signal to achieve immune suppression is critical in autoimmune diseases. However, the role of immune checkpoints in chronic inflammation and autoimmunity must still be deciphered. In this study, we investigated at the single-cell level the feature of T cells in JIA chronic inflammation, both at the transcriptome level via single-cell RNA sequencing and at the protein level by flow cytometry. We found that despite the heterogeneity in the composition of synovial CD4+ and CD8+ T cells, those characterized by PD-1 expression were clonally expanded tissue-resident memory (Trm)-like cells and displayed the highest proinflammatory capacity, suggesting their active contribution in sustaining chronic inflammation in situ. Our data support the concept that novel therapeutic strategies targeting PD-1 may be effective in the treatment of JIA. With this approach, it may become possible to target overactive T cells regardless of their cytokine production profile.

Predictors of lack of response to methotrexate in juvenile idiopathic arthritis associated uveitis.

OBJECTIVES: To investigate clinical features associated with lack of response to MTX in juvenile idiopathic arthritis associated uveitis (JIA-U). METHODS: Clinical records of JIA-U patients were retrospectively reviewed. Differences among variables were assessed by Mann-Whitney and χ 2 or Fisher's exact tests as appropriate. Association between predictors and requirement of a biological disease modifying antirheumatic drug (bDMARD) was evaluated by univariate Cox regression analysis and Kaplan-Meier curves. A multivariable logistic model was applied to estimate strength of association, adjusting for potential confounders. RESULTS: Data from 99 JIA-U patients treated with MTX were analysed (82.8% female), with a mean follow up of 9.2 years and a mean age at uveitis onset of 5.7 years. In 65 patients (65.7%) at least one bDMARD to control uveitis was required. Children requiring a bDMARD for uveitis had lower age at JIA and uveitis onset, more frequent polyarticular course, higher frequency of bilateral uveitis at onset and higher prevalence of systemic steroids' use. Despite similar frequency of ocular damage at onset, MTX non responders showed a higher percentage of ocular damage at last visit. Younger age at JIA onset, polyarticular course and a history of systemic steroids' use resulted independent factors associated to lack of response to MTX at Cox regression analysis. Kaplan-Meier curves and the multivariate model confirms the independent role of both polyarticular course and systemic steroids' use. CONCLUSIONS: Younger age at JIA onset, polyarticular course and a history of systemic steroids' use are predictors of a worse response to MTX in JIA-U.

Th17 lymphocyte-dependent degradation of joint cartilage by synovial fibroblasts in a humanized mouse model of arthritis and reversal by secukinumab.

How T-helper (Th) lymphocyte subpopulations identified in synovial fluid from patients with juvenile idiopathic arthritis (JIA) (Th17, classic Th1, or nonclassic Th1) drive joint damage is of great interest for the possible use of biological drugs that inhibit the specific cytokines. Our objective was to clarify the role of such Th subpopulations in the pathogenesis of articular cartilage destruction by synovial fibroblasts (SFbs), and the effect of Th17 blockage in an animal model. SFbs were isolated from healthy subjects and patients with JIA, and peripheral blood Th lymphocytes subsets were obtained from healthy subjects. Fragments of human cartilage from healthy subjects in a collagen matrix containing JIA or normal SFbs grafted underskin in SCID mice were used to measure cartilage degradation under the effects of Th supernatants. JIA SFbs overexpress MMP9 and MMP2 and Th17 induce both MMPs in normal SFbs, while nonclassic Th1 upregulate urokinase plasminogen activator (uPA) activity. In vitro invasive phenotype of normal SFbs is stimulated with conditioned medium of Th17 and nonclassic-Th1. In the in vivo "inverse wrap" model, normal SFbs stimulated with supernatants of Th17-lymphocytes and nonclassic Th1 produced a cartilage invasion and degradation similar to JIA SFbs. Secukinumab inhibits the cartilage damage triggered by factors produced by Th17.

Neuropsychiatric involvement in juvenile-onset systemic lupus erythematosus: Data from the UK Juvenile-onset systemic lupus erythematosus cohort study.

INTRODUCTION: Juvenile-onset systemic lupus erythematosus (JSLE) is a rare autoimmune/inflammatory disease with significant morbidity and mortality. Neuropsychiatric (NP) involvement is a severe complication, encompassing a heterogeneous range of neurological and psychiatric manifestations. METHODS: Demographic, clinical, and laboratory features of NP-SLE were assessed in participants of the UK JSLE Cohort Study, and compared to patients in the same cohort without NP manifestations. RESULTS: A total of 428 JSLE patients were included in this study, 25% of which exhibited NP features, half of them at first visit. Most common neurological symptoms among NP-JSLE patients included headaches (78.5%), mood disorders (48.6%), cognitive impairment (42%), anxiety (23.3%), seizures (19.6%), movement disorders (17.7%), and cerebrovascular disease (14.9%). Peripheral nervous system involvement was recorded in 7% of NP-SLE patients. NP-JSLE patients more frequently exhibited thrombocytopenia (<100 × 109/L) (p = 0.04), higher C-reactive protein levels (p = 0.01), higher global pBILAG score at first visit (p < 0.001), and higher SLICC damage index score at first (p = 0.02) and last (p < 0.001) visit when compared to JSLE patients without NP involvement. CONCLUSIONS: A significant proportion of JSLE patients experience NP involvement (25%). Juvenile-onset NP-SLE most commonly affects the CNS and is associated with increased overall disease activity and damage.

Serum calprotectin (S100A8/9), clinical and ultrasound assessment in patients with juvenile idiopathic arthritis.

OBJECTIVES: To explore the association between serum S100A8/9 (calprotectin), clinical and ultrasound (US) assessment in juvenile idiopathic arthritis (JIA) patients. METHODS: A total of 30 well-characterised consecutive patients (18 female) with non-systemic JIA and 20 age-matched healthy controls were included. Serum and plasma samples obtained the same day of the clinical and sonographical assessment were tested for calprotectin levels by ELISA. Clinical status was defined using Wallace criteria. Ultrasonographic B-mode and power Doppler (PD) assessment of 44 joints for each subject was performed. RESULTS: Clinically active disease was present in 14 patients, while 16 patients were active according to US evaluation. We found no differences in the serum/plasma calprotectin levels in clinically active disease group [29.6 (5.4-198.1) ng/ml; 12.6 (2.8-65.8) ng/ml] as compared with inactive disease group [24.8 (14.1-204.3); 12.7 (3.4-65.1)] (p=0.73; p=0.29). There was also no difference between US active disease [29.8 (5.4-204.3); 12.9 (2.8-65.8)] and US inactive disease [24.8 (12.1-197.1); 11.7 (3.4-44.2)] with regard to the serum/plasma calprotectin levels (p=0.83; p=1.0). Serum/plasma calprotectin levels correlated moderately with C-reactive protein (CRP) (Spearman r=0.44, p=0.01; Spearman r=0.56, p=0.0021). CONCLUSIONS: To our knowledge, this is the first study to simultaneously examine the correlation between serum/plasma calprotectin levels, clinical and US assessment in JIA. Calprotectin was not associated with the disease status in JIA patients with low number of active joints and its levels were moderately correlated with CRP. Our preliminary study needs to be extended with a larger number of patients.

Whole-body MRI in pediatric undefined inflammatory conditions.

BACKGROUND: Whole-body magnetic resonance imaging (WBMRI) is a multiregional imaging technique suitable for investigating the extent of multisystemic diseases without exposure to radiation, with a high sensitivity to bone alterations. The aim of our study was to evaluate the role of WBMRI in the workup of children with non-specific musculoskeletal features and non-indicative laboratory and instrumental data, who were suspected to have a rheumatologic disease. METHODS: We retrospectively analyzed medical records, including laboratory tests and radiological data of 34 children who had been evaluated due to non-specific musculoskeletal manifestations, for which a WBMRI was prescribed. RESULTS: We included 34 children, 19 females and 15 males, mean age 10 years (range 2-16 years), with the following clinical features: diffuse arthralgia (12 children), persistent fever (2 children), persistent fever and diffuse arthralgia (20 children). Serologic inflammatory markers were increased in 29/34 patients. Twenty-five children had already received X-ray and / or ultrasound before WBMRI, with a negative / uninformative result. WBMRI was performed 3-6 weeks (median, 3.5 weeks) after the initial presentation of symptoms. In 22/34 (65%) children, WBMRI revealed some abnormalities that supported the final diagnosis. Twelve out of 34 children (35%) were be affected by chronic recurrent multifocal osteomyelitis. CONCLUSIONS: WBMRI is helpful in pediatric rheumatology for the differential diagnosis of undefined inflammatory conditions. It appears to be a promising tool, especially in the detection of multifocal bone lesions. The diagnosis that mainly benefits from WBMRI in our series is chronic recurrent multifocal osteomyelitis. WBMRI can also help in excluding neoplastic diseases.

One year in review: Kawasaki disease.

PURPOSE OF REVIEW: Kawasaki disease is a childhood vasculitis of unknown origin, whose major complication is the development of coronary artery aneurysms (CAA). The purpose of this review is to provide an overview on the most recent evidence on the pathogenesis, diagnosis and treatment options of Kawasaki disease summarizing the most relevant studies published in the last year. RECENT FINDINGS: Several genetic polymorphisms leading to Kawasaki disease susceptibility have been identified, mostly related to immune system regulation; potential external triggers are being investigated by environmental epidemiology studies. A new diagnostic test based on trascriptomics has been tested with promising preliminary results. With regards to first-line treatments, the real effectiveness of high-dose aspirin remains a matter of debate. For refractory cases, the ones at the highest risk for developing CAA, promising results come from the use of biologic agents, especially TNF and IL-1 blockers. SUMMARY: Recent literature has provided interesting insights on the various factors involved in the complex scenario behind the pathogenesis of Kawasaki disease, especially genetic ones. Novel diagnostic tests and new evidence on the use of biologic agents in Kawasaki disease are emerging, but further evidence is needed to permit early diagnosis and effective treatment of this condition.

Alagille Syndrome and Chronic Arthritis: An International Case Series.

We describe 10 children with Alagille syndrome and inflammatory arthritis. In our centers, the prevalence of chronic arthritis in patients with Alagille syndrome is approximately 50 times higher compared with the general population. Arthritis was refractory to most treatment. Patients with Alagille syndrome should routinely be screened for musculoskeletal symptoms.

Chronic non-bacterial osteomyelitis: a retrospective international study on clinical manifestations and response to treatment.

OBJECTIVES: Chronic non-bacterial osteomyelitis (CNO) is a rare non-infectious bone inflammatory disorder; when multifocal, it is referred to as Chronic Recurrent Multifocal Osteomyelitis (CRMO). This study evaluates the demographic, clinical and radiological characteristics of a multi-centre cohort of patients with CNO/CRMO. METHODS: Demographic and clinical data of patients with an established diagnosis of CNO/CRMO followed at paediatric rheumatology centres across Europe (Italy, France, Slovenia) and India were retrospectively collected. RESULTS: There were no demographic differences across countries, but time to diagnosis was significantly longer in India (p=0.041). Pain was almost invariably present at disease onset; functional impairment was more frequent among Italian and Slovenian patients (p=0.001). The number of sites of bone involvement was similar between genders and countries, with long bone metaphises being the most common site. Raised acute phase reactants, detected in >50% of patients, were not associated with clinical manifestations or response to treatment. Comorbidities, evinced in 37% of patients, were equally distributed between genders and nationalities. Imaging approach was similar across countries, without any association between radiological findings and clinical manifestations. NSAIDs were almost invariably used as first-line treatment, but response rate was significantly lower in Italy (p=0.02). Methotrexate was used in 28% of case, with an overall rate of response of 82%. Health conditions and rate of permanent deformities were similar across different countries. CONCLUSIONS: The differences in clinical presentation, radiological features and response to treatment described in this multinational cohort of CNO/CRMO might provide novel insights into this still elusive disease.

Gut microbiota in children and altered profiles in juvenile idiopathic arthritis.

Microbial diversity plays a key role in the maintenance of intestinal homeostasis and in the development of the immune system in the gut mucosa. Maybe one of the most important function of our gut microbiota is the immune system education, in particular the discrimination of friends from foes that occurs during childhood. In addition to bacterial antigens, several metabolites of microbial origin have a crucial role in training of the immune system, such as Short Chain Fatty Acids (SCFAs). There are many evidences on the role of the gut microbiota in rheumatic diseases, in particular modifications of microbiota composition causing dysbiosis that, in turn, can induce gut permeability, and thus immunological imbalance and trigger inflammation. In particular, immune cells can reach extra-intestinal sites, such as joints and trigger local inflammation. Childhood is a crucial period of life for development and evolution of the gut microbiota, especially for the acquisition of fundamental functions such as immunotolerance of commensal microorganisms. For this reason, gut dysbiosis is gaining interest as a potential pathogenetic factor for Juvenile Idiopathic Arthritis (JIA). Here we summarized the studies conducted on JIA patients in which a pro-arthritogenic microbial profiles has been observed; this, together with a depletion of microbial biodiversity, clearly distinguish patients' from healthy subjects' microbiota. Further studies are however needed to better clarify the role of microbiota in JIA pathogenesis.

The First Pediatric Case of Acute Generalized Exanthematous Pustulosis Caused by Hydroxychloroquine.

INTRODUCTION: Acute generalized exanthematous pustulosis (AGEP) is a generalized, non-follicular sterile pustular rash, categorized as a severe cutaneous adverse reaction, which usually has a favorable prognosis. In a majority of cases (90%), AGEP is drug induced and different drugs are reported as cause of AGEP. Hydroxychloroquine (HCQ) is an antimalarial drug that is also used in some dermatologic and rheumatic diseases due to its immunosuppressive actions. Some cases of AGEP induced by HCQ are reported in literature but only in adults. MATERIALS, METHODS AND RESULTS: We describe the first case of AGEP caused by HCQ in a child affected by juvenile Sjögren syndrome. After withdrawal of HCQ and subsequent administration, the patient experienced the same cutaneous reaction. An allergy work-up was performed and patch test showed an ectopic flare of AGEP eruption. CONCLUSION: Our patient represents the first pediatric case of AGEP to HCQ, posing such a drug as a possible trigger also in children. Therefore, an accurate drug medical history is mandatory in order to rule out potential drug reactions when facing a sudden rash.

Evidence-Based Treatment for Uveitis.

BACKGROUND: Uveitis is an inflammatory disorder of the uveal tract of the eye that can affect both adults and children. Non-infectious uveitis can be an expression of a systemic autoimmune condition, or it can be idiopathic. It is a serious disease, associated with possible severe complications leading to visual impairment and blindness. For this reason, a prompt diagnosis and assessment of an appropriate treatment, with the collaboration of specialists such as ophthalmologists and rheumatologists, are extremely important. Many treatment options may be associated to side effects; therefore, clinicians should follow a stepladder approach starting with the least aggressive treatments to induce remission of inflammation. In this review, we reported the current evidence-based treatments for non-infectious uveitis in pediatric and adult patients with particular attention to the biologic response modifier treatment options. Important multicenter studies have demonstrated the efficacy of adalimumab, both in adults (VISUAL I, VISUAL II, VISUAL III) and in children (SYCAMORE, ADJUVITE), while for other agents data are still scarce.

Clinical Use and Molecular Action of Corticosteroids in the Pediatric Age.

Corticosteroids are the mainstay of therapy for many pediatric disorders and sometimes are life-saving. Both endogenous and synthetic derivatives diffuse across the cell membrane and, by binding to their cognate glucocorticoid receptor, modulate a variety of physiological functions, such as glucose metabolism, immune homeostasis, organ development, and the endocrine system. However, despite their proved and known efficacy, corticosteroids show a lot of side effects, among which growth retardation is of particular concern and specific for pediatric age. The aim of this review is to discuss the mechanism of action of corticosteroids, and how their genomic effects have both beneficial and adverse consequences. We will focus on the use of corticosteroids in different pediatric subspecialties and most common diseases, analyzing the most recent evidence.

Growth and body mass index in a cohort of patients with juvenile idiopathic arthritis: effects of second line treatments.

OBJECTIVES: Juvenile idiopathic arthritis (JIA) may affect natural growth. The aim of the study has been to assess auxological parameters of JIA patients, receiving different anti-rheumatic treatments. METHODS: This is a retrospective study; JIA patients were recruited from the Rheumatology Unit of Anna Meyer Children's University Hospital of Florence, Italy from March 1996 to June 2016. RESULTS: Two hundred and thirty-two patients were included in the current study. The best result in terms of catch-up growth occurred in systemic JIA patients. All JIA categories showed standard deviation score (SDS) gain for height except those belonging to enthesitis related arthritis category. Patients treated with disease-modifying anti-rheumatic drugs (DMARDs) only maintained constant growth during study follow-up. Patients who needed biologic therapy showed an impaired growth during pre-DMARDs treatment and an increased growth velocity mostly during biologic therapy. Body mass index (BMI) decreased in almost all JIA categories. The best BMI reduction was observed among patient receiving biologic drugs. CONCLUSIONS: Patients with JIA followed in our centre had a gain of height SDS and lost BMI SDS in 5 years of follow-up. We observed a stable and good pattern of growth in patients treated with DMARDs and an increased growth velocity during biologic treatment.

Joint pain management in children and adolescents.

In children, joint pain is common complaint and it proves challenging for primary care physicians. The possible differential diagnoses include a wide range of disorders, from the common and benign ones to serious and even life-threating conditions. An accurate work-up of these patients is needed, with thorough patient history and a systematic physical examination as essential tools. Clarifying the nature, the site, and the duration of the pain is fundamental as well as identifying systemic symptoms such as fever, weight loss, and night sweating. We will provide a description of the different clinical presentations of such disorders, and suggest how to approach a targeted patient history and a complete physical examination, which may lead to the appropriate investigation and consequently to the correct diagnosis.

Immunosuppressive Activity of Abatacept on Circulating T Helper Lymphocytes from Juvenile Idiopathic Arthritis Patients.

BACKGROUND: Abatacept is used in the treatment of juvenile idiopathic arthritis (JIA) patients, but the activity of the drug on T helper cell function is not yet fully known. METHODS: The ability of abatacept to affect cytokine production in vitro and the proliferative response to both recall antigens and polyclonal stimulation was firstly assessed in healthy donors. Then, 10 JIA patients who were due to start abatacept treatment were recruited and longitudinally evaluated during the first 90 days of therapy. Both their clinical response to the treatment and in vitro analysis aimed to assess the proliferative response to recall antigens and the proportions of circulating T helper subsets. RESULTS: Abatacept reduced the proliferative response to recall antigens and the production of proinflammatory cytokines such as IFN-γ and TNF-α in healthy donors in vitro. It was also efficient in improving symptoms and reducing parameters of inflammation in JIA patients. Abatacept reduced the proliferative response to recall antigens, and this effect was significant soon after drug infusion (2 days). Regarding the proportions of circulating CD4+ T lymphocytes, only a reduction in the frequencies of circulating Treg cells was observed. CONCLUSIONS: Abatacept in vitro inhibits proliferation and cytokine production in healthy donors, and reduces parameters of inflammation in vivo in JIA patients. The reduction of the proliferative response to recall antigens induced by abatacept was evident only soon after drug administration, suggesting that its immunosuppressive activity is maintained only for a short time.