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. The pediatrician must weigh a wide range of acute and chronic potential causes of a non-traumatic limp, including infection, neoplasia, and chronic inflammatory disorders. A thorough history and clinical examination will help us arrive at the correct diagnosis. Understanding the typical gait is essential to recognizing and correctly interpreting the disordered one. The examination of child limping involves using a variety of diagnostic methods. Efficient and cost-effective diagnosis and treatment of the underlying condition requires a systematic approach. This review provides the pediatric rheumatologist perspective and approach for evaluating non-traumatic limp in children, with a focus on the use of point-of-care (PoC) musculoskeletal ultrasound (MSUS) as a crucial tool in daily practice.

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. Methods: Febrile children aged 0-36 months with suspected UTI based on positive urinalysis or viral respiratory tract infection were included. Children with significant bacteriuria in urine culture were labeled as cases (n = 58), while those with confirmed viral infection (n = 51), as well as those with suspected UTI but sterile urine culture who went on to develop symptoms consistent with viral respiratory infection (n = 7), were labeled as controls. sCal levels were determined by a commercial immunoassay. Conventional inflammation markers (C-reactive protein, procalcitonin, white blood cell count, absolute neutrophil count, and neutrophil percentage) were measured on the day of the clinical examination. Differences in measured inflammatory markers between cases and controls were analyzed with Mann-Whitney U-test. ROC analysis reported cut-off values with the best sensitivity and specificity to distinguish bacterial UTI from viral respiratory infection. Results: All analyzed inflammatory biomarkers, including sCal, were significantly higher in cases than in controls. Median concentration of sCal was 4.97 µg/mL (IQR 3.43-6.42) and 2.45 µg/mL (IQR 1.63-3.85) for cases and controls, respectively (p < 0.001). For identifying bacterial UTI, sensitivity and specificity of sCal were 77.6 and 69.0%, respectively, at an adjusted cut-off point of >3.24 µg/mL (AUC 80.2%). Conclusion: sCal could have substantial added value in the management of a child with fever and positive urinalysis and is a promising biomarker in distinction between bacterial UTI and viral respiratory causes of febrile illness in children under the age of 3 years.

Value of thymic stromal lymphopoietin as a biomarker in children with asthma.

BACKGROUND: Thymic stromal lymphopoietin (TSLP), an epithelium-derived pro-inflammatory cytokine, activates distinct immune and non-immune cells. It has been shown to be a master regulator of type 2 immune responses. Limited information is available on TSLP in childhood asthma. The aim of the present study was to find out whether there is association between TSLP concentrations and asthma phenotypes or disease activity. METHODS: A total of 207 children with asthma and 100 healthy children aged 1-13 years were enrolled. This study examined serum TSLP concentrations using ELISA Kit in asthma patients and controls, analyzed its correlation with asthma phenotypes and pulmonary function. We also examined TSLP concentrations in 23 patients during stable asthma and in acute asthma exacerbation. RESULTS: The serum concentrations of TSLP were significantly elevated in asthma patients compared with healthy controls (p < 0.05), but there was no significant difference (p > 0.05) in TSLP concentrations between three different asthma phenotypes (allergic asthma, virus induced asthma and nonallergic asthma). There was no significant correlation between TSLP concentrations and FEV1pred% (r = 0.01, p > 0.05). In the acute asthma exacerbation TSLP concentrations were not significantly different than in stable phase of disease (p > 0.05). CONCLUSION: Children with asthma have higher serum TSLP concentrations when compared to healthy controls. TSLP does not seem to be a biomarker of disease exacerbation in children. Different asthma phenotypes have similar TSLP concentration profile in peripheral blood and TSLP does not seem to be useful biomarker in asthma phenotyping 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. Accumulated evidence suggests that, in affected patients, subclinical gut inflammation caused by intestinal dysbiosis, is pivotal to the future development of synovial-entheseal complex inflammation. While the predominant role of IL17/23 axis, TNF-α, and IL-7 in the pathophysiology of SpA, including jSpA, is firmly established, the role of the cytokine macrophage migration inhibitory factor (MIF) is generally overlooked. The purpose of this review is to discuss and emphasize the role of epigenetics, neuroendocrine pathways and the hypothalamic-pituitary (HPA) axis, and to propose a novel hypothesis of the role of decreased NLRP3 gene expression and possibly MIF in the early phases of jSpA development. The decreased NLRP3 gene expression in the latter, due to hypomethylation of promotor site, is (one of) the cause for inflammasome malfunction leading to gut dysbiosis observed in patients with early jSpA. In addition, we highlight the role of MIF in the complex innate, adaptive cellular and main effector cytokine network, Finally, since treatment of advanced bone pathology in SpA remains an unmet clinical need, I suggest possible new drug targets with the aim to ultimately improve treatment efficacy and long-term outcome of jSpA patients.

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. The cross-sectional exploratory study involving 71 patients with ERA, other forms of JIA and children complaining musculoskeletal symptoms was therefore conducted. Along with fCAL assessment, a detailed clinical and laboratory examination was performed, including the calculation of a composite disease activity scores. Moreover, MRI of the sacroiliac joints was performed in all ERA and other patients complaining of low back pain. The median concentration of fCAL was highest in ERA patients (33.2 mg/kg, p = 0.02), with a significant difference between those with inactive and active disease (20.0 vs. 57.4, p = 0.01), as well as those with and without MRI signs of sacroiliitis (22.6 vs. 54.3, p = 0.04). The fCAL did not differ depending on the NSAID use (23 vs. 20, p = 0.18), although weak correlation was observed with the treatment duration (r = 0.25, p = 0.03). In conclusion, our findings indicate that a parallel inflammation in musculoskeletal system and gut can occur not just in adults with SpA, but in children with ERA as well.

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. She first presented at the age of 4 with swelling and contractures of both knees. Her symptoms were initially unresponsive to nonsteroidal anti-inflammatory drugs and progressed despite treatment with intraarticular and systemic glucocorticoids and methotrexate. Throughout the years, she received several biologics together with continuous administration of nonsteroidal anti-inflammatory drugs and disease modifying anti-rheumatic drugs as well as intraarticular and systemic glucocorticoids in disease flares. However, none of this options  provided a permanent remission, so various other modalities, as well as other possible diagnoses were constantly being considered. Eventually she became dependent on a daily dose of systemic glucocorticoids. In 2018, the treatment with Janus kinase inhibitor tofacitinib was initiated, which led to gradual amelioration of musculoskeletal symptoms, improvement of inflammatory markers and overall well-being, as well as to the weaning of systemic glucocorticoids. As the swelling of the wrists subsided for the first time in many years, Madelung's deformity was noticed, first clinically, and later radiographically as well. Genetic analysis revealed short-stature homeobox gene deficiency and confirmed the diagnosis of Leri Weill syndrome. CONCLUSIONS: This case report emphasizes the need for reporting refractory, complicated cases from everyday clinical practice in order to build-up the overall knowledge and share experience which is complementary to available guidelines. Individual reports of difficult to treat cases, especially when additional diagnoses are involved, can be helpful for physicians treating patients with common rheumatological diseases such as juvenile idiopathic arthritis.

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. Concordance between criteria was examined using weighted Venn diagrams. The role of each individual component in explaining discordance between criteria was assessed by calculating the absolute number and percentage of instances in which the component was responsible for discrepancy between definitions. RESULTS: Criteria for ID were met by 28.6-41.1% of patients with oligoarthritis and by 24.0-33.4% of patients with polyarthritis. Criteria for LDA were met by 44.8-62.4% of patients with oligoarthritis and by 44.6-50.4% of patients with polyarthritis. There was a 57.9-62.3% overlap between criteria for ID and a 67.9-85% overlap between criteria for LDA. Parent and physician global assessments and acute-phase reactants were responsible for the majority of instances of discordance among criteria for ID (8.7-15.5%, 10.0-12.3%, and 10.8-17.3%, respectively). CONCLUSION: We found fair concordance between criteria for ID and LDA in JIA, with the main drivers of discordance for ID being physician and parent global assessments and acute-phase reactants. This observation highlights the need for further studies aimed to evaluate the impact of subjective physician and parent perception of disease remission and of laboratory measures of inflammatory activity on the definition of ID.

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. We found a significant reduction in parent-adjusted height Z score over time in female patients (P < 0.0001) and male patients (P = 0.001), but with catch-up growth at the final study visit. Median body mass index Z score peaked at 6 months (P < 0.0001) and was still significantly above baseline at the final study visit, which was at a median of 26 months after baseline (P = 0.007), with no difference between sexes. Female patients with a disease duration ≥12 months after onset had significantly lower parent-adjusted height Z score (P = 0.002) and no 2-year catch-up growth. At the final study visit, growth failure was seen in 20 of 97 female patients (21%) and in 11 of 73 male patients (15%). Height deflection (∆height Z score less than -0.25/year) was observed in 29 of 116 female patients (25%) and 25 of 80 male patients (31.3%). Delayed puberty was seen in 20 of 55 female patients (36.4%) and in 11 of 31 male patients (35.5%). Children in early pubertal stage at baseline had the highest risk of growth failure. CONCLUSION: Juvenile DM in the active phase and/or its treatment has a significant impact on growth and puberty in affected children. Children with recent onset of puberty or previous growth failure have the highest risk of delayed pubertal development and further growth retardation.

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. CASE PRESENTATION: A misdiagnosed ten-and-a-half-year-old girl with osteoid osteoma involving the distal phalanx of a little finger is presented. Her initial symptoms were pain and swelling of the little finger resembling dactylitis, while various imaging modalities showed signs of tenosynovitis, indicating a possible development of juvenile spondyloarthritis. Several trials of different non-steroid anti-inflammatory drugs gave no satisfactory results and ultrasound guided triamcinolone-hexacetonide injection provided only a short relief. Finally, almost three years after initial presentation, persistent clinical symptoms warranted repeated imaging that raised suspicion of an osteoid osteoma. Directed treatment with surgical intervention led to almost immediate and complete resolution of her symptoms. CONCLUSIONS: Osteoid osteoma should be suspected in case of a tender swelling of a digit in children and adolescents, regardless of initial imaging findings and clinical presentation. Early diagnosis and treatment of this benign condition can have a substantial impact on quality of life of patients and their families and protect them from many unnecessary diagnostic procedures and treatment.

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. Each participating centre was asked to collect demographic, clinical data and the JAMAR in 100 consecutive JIA patients or all consecutive patients seen in a 6-month period and to administer the JAMAR to 100 healthy children and their parents. The statistical validation phase explored descriptive statistics and the psychometric issues of the JAMAR: the 3 Likert assumptions, floor/ceiling effects, internal consistency, Cronbach's alpha, interscale correlations, test-retest reliability and construct validity (convergent and discriminant validity). A total of 100 JIA patients (7% systemic, 38% oligoarticular, 19% RF negative polyarthritis, 36% other categories) and 100 healthy children, were enrolled in the paediatric rheumatology centres of the Clinical Hospital Center Sestre Milosrdnice and Childen's Hospital Srebrnjak in Zagreb. The JAMAR components discriminated well healthy subjects from JIA patients. All JAMAR components revealed satisfactory psychometric performances. In conclusion, the Croatian version of the JAMAR is a valid tool for the assessment of children with JIA and is suitable for use both in routine clinical practice and clinical research.

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. CRP was measured using Meso Scale Discovery immunoassay. Active joint counts, standardization uveitis nomenclature for anterior uveitis cells and vitreous haze by Nussenblatt scale were the clinical parameters. RESULTS: Multiplex Luminex arrays identified S100A12 as the most significantly elevated protein in five selected BS vs eight NHVs and this was confirmed by ELISA on additional samples from the same five BS patients. In the patient cohort, S100A12 (n = 39) and S100A8/9 (n = 33) were significantly higher compared with NHVs (n = 44 for S100A12, n = 40 for S100A8/9) (P = 0.0000004 and P = 0.0003, respectively). Positive correlations between active joint counts and S100 levels were significant for S100A12 (P = 0.0008) and S100A8/9 (P = 0.015). CRP levels did not correlate with active joint count. Subgroup analysis showed significant association of S100 proteins with active arthritis (S100A12 P = 0.01, S100A8/9 P = 0.008). Active uveitis was not associated with increased S100 levels. CONCLUSION: S100 proteins are biomarkers of articular disease activity in BS and potential outcome measures in future clinical trials. As secreted neutrophil and macrophage products, S100 proteins may reflect the burden of granulomatous tissue in BS.

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. METHODS: Twenty patients (30 joints) were treated with intraarticular infliximab and monitored by power Doppler musculoskeletal ultrasound according to the OMERACT and Juvenile Arthritis Disease Activity Score (JADAS 10) before intraarticular application and during the follow-up period of 18 months (0, 1, 12, 18 months). RESULTS: The results showed statistically significant improvement in PD-MSUS measures and JADAS in both B mode and power Doppler mode scores (p<0.001, p<0.001, respectively) in patients treated with i.a. infliximab with persistent response in fifteen patients. The JADAS score, as well as the ultrasound scores, were significantly reduced during the follow-up period. CONCLUSIONS: This study showed promising results, good safety and potential for the clinical benefit of intraarticular infliximab treatment in a selected group of patients with oligoarticular subtype of JIA.

Blau Syndrome-Associated Uveitis: Preliminary Results From an International Prospective Interventional Case Series.

PURPOSE: Provide baseline and preliminary follow-up results in a 5-year longitudinal study of Blau syndrome. DESIGN: Multicenter, prospective interventional case series. METHODS: Baseline data from 50 patients from 25 centers worldwide, and follow-up data for patients followed 1, 2, or 3 years at the end of study enrollment. Ophthalmic data were collected at baseline and yearly visits by means of a standardized collection form. RESULTS: Median age at onset of eye disease was 60 months and duration of eye disease at baseline 145 months. At baseline 38 patients (78%) had uveitis, which was bilateral in 37 (97%). Eight patients (21%) had moderate to severe visual impairment. Panuveitis was found in 38 eyes (51%), with characteristic multifocal choroidal infiltrates in 29 eyes (39%). Optic disc pallor in 9 eyes (12%) and peripapillary nodules in 9 eyes (12%) were the commonest signs of optic nerve involvement. Active anterior chamber inflammation was noted in 30 eyes (40%) at baseline and in 16 (34%), 17 (57%), and 11 (61%) eyes at 1, 2, and 3 years, respectively. Panuveitis was associated with longer disease duration. At baseline, 56 eyes (75%) were on topical corticosteroids. Twenty-six patients (68%) received a combination of systemic corticosteroids and immunomodulatory therapy. CONCLUSIONS: Blau uveitis is characterized by progressive panuveitis with multifocal choroiditis, resulting in severe ocular morbidity despite continuous systemic and local immunomodulatory therapy. The frequency and severity of Blau uveitis highlight the need for close ophthalmologic surveillance as well as a search for more effective therapies.

[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. To meet these criteria, a patient should have arthritis and/or enthesitis, with two or more symptoms such as sacroiliac joint tenderness and/or inflammatory back pain, HLAB27 genotype, HLA B27 genotype-associated disease in a first- or second-degree relative, uveitis, and male sex with eight or more years of age. Therefore, diagnosis is most oft en made only based on clinical examination and medical history. Anti- nuclear antibodies (ANA), rheumatoid factor (RF), and HLA testing with B27, B7, and DR4 alleles are preferred. Since subclinical gut inflammation is present in many patients, it is recommended to check fecal calprotectin levels. In patients with signs of peripheral enthesitis it is warranted to perform power Doppler musculoskeletal ultrasound (PDUS), and in patients with signs of axial involvement radiographic and contrast-enhanced magnetic resonance imaging. Most patients are treated with nonsteroidal anti-inflammatory drugs (NSAIDs) and physical therapy, while in refractory cases with peripheral disease synthetic disease- modifying antirheumatic drugs (DMARDs), such as sulfasalazine, are used. In patients with axial involvement, biological DMARDs such as adalimumab, infliximab, and etanercept are obligatory. Although a number of studies gave us a good insight into the disease pathogenesis, the response to treatment and prognosis are still difficult to predict.

[MICROARRAY AND GENE EXPRESSION ANALYSIS]. / SITNOPOLJE I ANALIZA GENSKOG IZRAZAJA.

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. Gene expression differences in two groups of samples are discovered and quantificated by comparison of signal intensity values in microarray spots. Systemic analysis of data gathered in microarray gene expression measurement is performed by various bioinformatic methods such as group analysis, annotation analysis as well as network and pathway analysis. Expression comparison of all genes in different cells of the same individual or same cells of different individuals provides an insight into the mechanism responsible for development of a certain condition or disease.

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. We undertook this large multicenter case-control study to determine whether SLE is associated with altered IgG glycosylation. METHODS: Using ultra-performance liquid chromatography analysis of released glycans, we analyzed the composition of the IgG glycome in 261 SLE patients and 247 matched controls of Latin American Mestizo origin (the discovery cohort) and in 2 independent replication cohorts of different ethnicity (108 SLE patients and 193 controls from Trinidad, and 106 SLE patients and 105 controls from China). RESULTS: Multiple statistically significant differences in IgG glycome composition were observed between patients and controls. The most significant changes included decreased galactosylation and sialylation of IgG (which regulate proinflammatory and antiinflammatory actions of IgG) as well as decreased core fucose and increased bisecting N-acetylglucosamine (which affect antibody-dependent cell-mediated cytotoxicity). CONCLUSION: The IgG glycome in SLE patients is significantly altered in a way that decreases immunosuppressive action of circulating immunoglobulins. The magnitude of observed changes is associated with the intensity of the disease, indicating that aberrant IgG glycome composition or changes in IgG glycosylation may be an important molecular mechanism 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. Statistically significant difference in genotype frequency for Thr399Ile SNP of TLR4 was observed in the jSpA (χ2 = 6.705, p = 0.035) and not in the JIA group (χ2 = 3005, p = 0.223). Regarding Asp299Gly SNP, no significant difference in genotype frequency was found; however, allele frequency was significant in both jSpA and JIA patients. No significant difference in genotype or allele frequency was observed for Arg735Gln and Q705K SNP. The399Ile polymorphism of TLR4 may be responsible for altered immune response to microbial infection in variant carriers and represent a mechanism of triggering overproduction of proinflammatory cytokines and long-term inflammation in jSpA. SNP of TLR2, NLRP3, and TLR4 (Asp299Gly) were not associated with jSpA or JIA.

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. Of the 31 patients, 11 carried the p.R334W NOD2 mutation, 9 the p.R334Q and 11 various other NOD2 missense mutations; 20 patients were sporadic and 11 from five BS pedigrees. Median disease duration was 12.8 years (1.1-57). Arthritis, documented in all but one patient, was oligoarticular in 7, polyarticular in 23. The median active joint count was 21. Functional capacity was normal in 41%, mildly impaired in 31% and moderate-severe in 28% of patients. The most frequently involved joints at presentation were wrists, ankles, knees and PIPs. On radiographs, a symmetrical non-erosive arthropathy was shown. Previously unknown dysplastic bony changes were found in two-thirds of patients. Ocular disease was documented in 25 of 31 patients, with vitreous inflammation in 64% and moderate-severe visual loss in 33%. Expanded manifestations (visceral, vascular) beyond the classic clinical triad were seen in 52%. CONCLUSION: BS is associated with severe ocular and articular morbidity. Visceral involvement is common and may be life-threatening. Bone dysplastic changes may show diagnostic value and suggest a previously unknown role of NOD2 in bone morphogenesis. BS is resistant to current drugs, suggesting the need for novel targeted therapies.