Non-traumatic Limping in the Child: A Pediatric Rheumatologist Perspective on Etiology, Clinical Evaluation, Laboratory Diagnosis, and Diagnostic Algorithms using Musculoskeletal Ultrasound (MSUS).

Limping refers to an asymmetrical gait that deviates from the typical gait pattern expected for a child of a certain age. In most children, limping is caused by a mild, self-limiting event, such as a contusion, strain, or sprain. However, a child's limping is always a pathological finding that poses a particular diagnostic challenge and necessitates a thorough assessment.

Serum Calprotectin Is a Valid Biomarker in Distinction of Bacterial Urinary Tract Infection From Viral Respiratory Illness in Children Under 3 Years of Age.

Background: Febrile illnesses in young children can be a major diagnostic challenge, despite the routine use of various laboratory markers. Recent advancements in the understanding of inflammatory processes have highlighted the role of calprotectin, a heterodimer consisting of S100A8 and S100A9 proteins, with many studies suggesting its clinical value as a biomarker of inflammation. This research aimed to evaluate the usefulness of serum calprotectin (sCal) as a biomarker of urinary tract infection (UTI), which was due to its high pooled prevalence and feasibility of urine culture as a diagnostic reference standard selected for a model of bacterial infection in children.

Immunopathophysiology of Juvenile Spondyloarthritis (jSpA): The "Out of the Box" View on Epigenetics, Neuroendocrine Pathways and Role of the Macrophage Migration Inhibitory Factor (MIF).

Juvenile spondyloarthritis (jSpA) is a an umbrella term for heterogeneous group of related seronegative inflammatory disorders sharing common symptoms. Although it mainly affects children and adolescents, it often remains active during adulthood. Genetic and environmental factors are involved in its occurrence, although the exact underlying immunopathophysiology remains incompletely elucidated.

The Increased Levels of Fecal Calprotectin in Children With Active Enthesitis Related Arthritis and MRI Signs of Sacroiliitis: The Results of a Single Center Cross-Sectional Exploratory Study in Juvenile Idiopathic Arthritis Patients.

Enthesitis related arthritis (ERA) is a specific subtype of juvenile idiopathic arthritis (JIA), often regarded as an undifferentiated form of juvenile spondyloarthritis (jSpA). While gut is increasingly recognized as origin and/or target of inflammation in adult onset spondyloarthritis (SpA), the incidence of gut involvement in ERA patients is largely unknown. The aim of this study was to measure the concentration of fecal calprotectin (fCAL), a surrogate marker of gut inflammation, in patients with different subtypes of JIA, as well as to correlate the results with various demographic, clinical, laboratory, imaging, and treatment characteristics.

Beyond the guidelines management of juvenile idiopathic arthritis: a case report of a girl with polyarticular disease refractory to multiple treatment options and Leri Weill syndrome.

Background: The last two decades brought new treatment options and high quality guidelines into the paediatric rheumatologic practice. Nevertheless, a number of patients still present a diagnostic and therapeutic challenge due to combination of vague symptoms and unresponsiveness to available treatment modalities.

Case Presentation: We report a case of sixteen years old girl suffering from polyarticular type of juvenile idiopathic arthritis refractory to multiple treatment options.

Determinants of Discordance Between Criteria for Inactive Disease and Low Disease Activity in Juvenile Idiopathic Arthritis.

Objective: To assess concordance among criteria for inactive disease (ID) and low disease activity (LDA) in juvenile idiopathic arthritis (JIA) and to seek factors driving discordance.

Methods: The frequency of fulfillment of existing criteria was evaluated in information on 10,186 patients extracted from 3 cross-sectional data sets. Patients were divided up according to the functional phenotypes of oligoarthritis and polyarthritis.

Growth and Puberty in Juvenile Dermatomyositis: A Longitudinal Cohort Study.

Objective: To study growth and puberty in a multinational longitudinal prospective cohort of children with juvenile dermatomyositis (DM).

Methods: Children from 31 countries who were ages <18 years and had juvenile DM in active phase were studied, and analyses of height, weight, and pubertal development were conducted in those who had follow-up visits during a 2-year period and for whom anthropometric data was available.

Results: A total of 196 of 275 children (71%) were included.

Unusual localization and presentation of osteoid osteoma mimicking juvenile spondyloarthritis: a case report.

Background: Osteoid osteoma is a painful benign skeletal tumour of unknown aetiology. Most often it occurs in the long bones of extremities and responds well to nonsteroidal anti-inflammatory medications. However, unusual localization and atypical presentation of this tumour might present a diagnostic challenge, especially if symptoms mimic that indicative of juvenile spondyloarthritis.

The Croatian version of the Juvenile Arthritis Multidimensional Assessment Report (JAMAR).

The Juvenile Arthritis Multidimensional Assessment Report (JAMAR) is a new parent/patient reported outcome measure that enables a thorough assessment of the disease status in children with juvenile idiopathic arthritis (JIA). We report the results of the cross-cultural adaptation and validation of the parent and patient versions of the JAMAR in the Croatian language. The reading comprehension of the questionnaire was tested in 10 JIA parents and patients.

S100A12 and S100A8/9 proteins are biomarkers of articular disease activity in Blau syndrome.

Objective: To identify biomarkers of articular and ocular disease activity in patients with Blau syndrome (BS).

Methods: Multiplex plasma protein arrays were performed in five BS patients and eight normal healthy volunteers (NHVs). Plasma S100A12 and S100A8/9 were subsequently measured by ELISA at baseline and 1-year follow-up in all patients from a prospective multicentre cohort study.

Intraarticular infliximab therapy in patients with juvenile idiopathic arthritis: the role of musculoskeletal ultrasound and disease activity scores in monitoring therapy response.

Objectives: Juvenile idiopathic arthritis (JIA) is the most common chronic rheumatic disease in children, with heterogeneous clinical features. Although therapeutic options are wide and in the majority of children symptoms improve with the combination of non-steroidal anti-inflammatory and disease-modifying drugs, there are a number of patients who do not respond to conventional therapy and who do not meet the criteria for systemic biologics, namely anti TNF-alpha. Those patients are potential candidates for intraarticular therapy with biologics and in this report we present the results of intra-articular infliximab treatment in a series of patients diagnosed with oligoarticular subtype of JIA.

[PATHOGENESIS OF UNDIFFERENTIATED SPONDYLOARTHRITIS].

Spondyloarthritis or spondyloarthropathy (SpA) is a multifactorial disease in which a disturbed interplay occurs between the immune system and environmental factors on a predisposing genetic background, which leads to inflammation and structural damage of target tissue. Many recent researches on development of SpA showed important role of innate and adaptive immunity as well as of prominent bone tissue remodeling which leads to osteoproliferation and ankylosis. It is believed that possible sites of inflammation in SpA are entheses, sinovium and gut.

[JUVENILE SPONDYLOARTHRITIS].

Juvenile spondyloartrhritis is a group of multifactorial diseases in which a disturbed interplay occurs between the immune system and environmental factors on a predisposing genetic background, which leads to inflammation and structural damage of the target tissue. First symptoms of jSpA rarely involve the spine, while asymmetrical oligoarthritis of lower extremities, dactylitis, and peripheral enthesitis are much more common. There are many classification criteria for jSpA, but the majority of pediatric rheumatologists currently use the International League Against Rheumatism (ILAR) criteria according to which most patients with jSpA are classified into the enthesitis-related arthritis group of juvenile idiopathic arthritis.

[MICROARRAY AND GENE EXPRESSION ANALYSIS].

Microarray gene expression analysis is high-throughput method in which many different sized DNA molecules are attached to solid surface in designated spots. These molecules are used for the discovery of specific RNA molecules isolated from various biological samples of interest. Core principle of this method is hybridization of complementary nucleotides (A-T and G-C), which leads to creation of double stranded nucleic acids.

Association of systemic lupus erythematosus with decreased immunosuppressive potential of the IgG glycome.

Objective: Glycans attached to the Fc portion of IgG are important modulators of IgG effector functions. Interindividual differences in IgG glycome composition are large and they associate strongly with different inflammatory and autoimmune diseases. IKZF1, HLA-DQ2A/B, and BACH2 genetic loci that affect IgG glycome composition show pleiotropy with systemic lupus erythematosus (SLE), indicating a potentially causative role of aberrant IgG glycosylation in SLE.

Single nucleotide polymorphism of toll-like receptor 4 (TLR4) is associated with juvenile spondyloarthritis in Croatian population.

Single nucleotide polymorphisms (SNP) of toll-like and NOD-like receptors have been associated with altered receptor activity and modified production of proinflammatory cytokines leading to a number of diseases. Our aim was to determine whether SNP of TLR2 (Arg753Gln), TLR4 (Asp299Gly, Thr399Ile), and NLRP3 (Q705K) influence susceptibility to juvenile spondyloarthrtis (jSpA) and juvenile idiopathic arthritis (JIA). After the DNA extraction, 26 patients with jSpA, 11 with oligoarticular, polyarticular, or systemic JIA, and 40 healthy controls were genotyped for Arg753Gln, Asp299Gly, Thr399Ile, and Q705K SNP using real-time PCR-SNP analysis.

[Genetic predisposition for various forms of spondyloarthritis].

In addition to the long-established association of HLA-B27 antigen and spondyloarthritis, several studies have shown a similar association with HLA-B7 antigen. But since the whole MHC region carries less than half of the risk for the development of the disease, the main goal of many recently performed researches, which implemented various high-throughput methods, was to discover the influence of genes outside the MHC region on disease development. The results showed that genes closely linked to spondyloarthritis participate in antigen processing and coding of various cytokines.

Aberrant expression of shared master-key genes contributes to the immunopathogenesis in patients with juvenile spondyloarthritis.

Association of juvenile spondyloarthritis (jSpA) with the HLA-B27 genotype is well established, but there is little knowledge of other genetic factors with a role in the development of the disease. To date, only a few studies have tried to find those associated genes by obtaining expression profiles, but with inconsistent results due to various patient selection criteria and methodology. The aim of the present study was to identify and confirm gene signatures and novel biomarkers in highly homogeneous cohorts of untreated and treated patients diagnosed with jSpA and other forms of juvenile idiopathic arthritis (JIA) according to ILAR criteria.

Blau syndrome: cross-sectional data from a multicentre study of clinical, radiological and functional outcomes.

Objective: To report baseline articular, functional and ocular findings of the first international prospective cohort study of Blau syndrome (BS).

Methods: Three-year, multicentre, observational study on articular, functional (HAQ, Childhood HAQ and VAS global and pain), ophthalmological, therapeutic and radiological data in BS patients.

Results: Baseline data on the first 31 recruited patients (12 females and 19 males) from 18 centres in 11 countries are presented.

[Guidelines on biologic drugs for the treatment of children with juvenile idiopathic arthritis (JIA)].

Juvenile idiopathic arthritis (JIA) is the most common chronic rheumatic disease in children, and one of the major causes of short-term or long-term disability, and impairment of quality of life in childhood. Without early and adequate treatment the disease will progress and result with irreparable joint damage. The choice of therapy depends on the JIA subtype, disease activity index, prognostic factors, and prooven efficacy and probable side-effects of the drugs.