"Deficiency in ELF4, X-Linked": a Monogenic Disease Entity Resembling Behçet's Syndrome and Inflammatory Bowel Disease.

Defining monogenic drivers of autoinflammatory syndromes elucidates mechanisms of disease in patients with these inborn errors of immunity and can facilitate targeted therapeutic interventions. Here, we describe a cohort of patients with a Behçet's- and inflammatory bowel disease (IBD)-like disorder termed "deficiency in ELF4, X-linked" (DEX) affecting males with loss-of-function variants in the ELF4 transcription factor gene located on the X chromosome. An international cohort of fourteen DEX patients was assessed to identify unifying clinical manifestations and diagnostic criteria as well as collate findings informing therapeutic responses. DEX patients exhibit a heterogeneous clinical phenotype including weight loss, oral and gastrointestinal aphthous ulcers, fevers, skin inflammation, gastrointestinal symptoms, arthritis, arthralgia, and myalgia, with findings of increased inflammatory markers, anemia, neutrophilic leukocytosis, thrombocytosis, intermittently low natural killer and class-switched memory B cells, and increased inflammatory cytokines in the serum. Patients have been predominantly treated with anti-inflammatory agents, with the majority of DEX patients treated with biologics targeting TNFα.

Gene signature fingerprints stratify SLE patients in groups with similar biological disease profiles: a multicentre longitudinal study.

OBJECTIVES: Clinical phenotyping and predicting treatment responses in SLE patients is challenging. Extensive blood transcriptional profiling has identified various gene modules that are promising for stratification of SLE patients. We aimed to translate existing transcriptomic data into simpler gene signatures suitable for daily clinical practice. METHODS: Real-time PCR of multiple genes from the IFN M1.2, IFN M5.12, neutrophil (NPh) and plasma cell (PLC) modules, followed by a principle component analysis, was used to identify indicator genes per gene signature. Gene signatures were measured in longitudinal samples from two childhood-onset SLE cohorts (n = 101 and n = 34, respectively), and associations with clinical features were assessed. Disease activity was measured using Safety of Estrogen in Lupus National Assessment (SELENA)-SLEDAI. Cluster analysis subdivided patients into three mutually exclusive fingerprint-groups termed (1) all-signatures-low, (2) only IFN high (M1.2 and/or M5.12) and (3) high NPh and/or PLC. RESULTS: All gene signatures were significantly associated with disease activity in cross-sectionally collected samples. The PLC-signature showed the highest association with disease activity. Interestingly, in longitudinally collected samples, the PLC-signature was associated with disease activity and showed a decrease over time. When patients were divided into fingerprints, the highest disease activity was observed in the high NPh and/or PLC group. The lowest disease activity was observed in the all-signatures-low group. The same distribution was reproduced in samples from an independent SLE cohort. CONCLUSIONS: The identified gene signatures were associated with disease activity and were indicated to be suitable tools for stratifying SLE patients into groups with similar activated immune pathways that may guide future treatment choices.

Use of Mycophenolate Mofetil in Patients with Severe Localized Scleroderma Resistant or Intolerant to Methotrexate.

To assess the efficacy and safety of mycophenolate mofetil (MMF) in patients with localized scleroderma (LoS) resistant or intolerant to previous treatment with methotrexate (MTX). A case series of patients with LoS treated with MMF. Outcome was assessed through clinical examination. Adverse events were documented. Seven patients with LoS were treated with MMF. Median age at MMF initiation was 15 years (range 7-74 years). Three patients received MMF due to MTX ineffectiveness and 4 due to MTX intolerance. Disease remission was achieved in 4 patients and maintained in one patient. One patient showed a favourable response, but had to discontinue treatment due to elevated liver enzymes. The remaining patient experienced disease progression. MMF was shown to improve the clinical condition of patients with refractory LoS and may be a relatively safe alternative in patients who are intolerant to MTX.

Trends in prescription of biological agents and outcomes of juvenile idiopathic arthritis: results of the Dutch national Arthritis and Biologics in Children Register.

BACKGROUND: Treatment of juvenile idiopathic arthritis (JIA) has changed dramatically since the introduction of biological agents in 1999. OBJECTIVE: To evaluate trends in prescription patterns of biological agents and the subsequent outcome of JIA. METHODS: The Arthritis and Biologics in Children register (multicentre prospective observational study) aimed to include all consecutive patients with JIA in the Netherlands who had started biological agents since 1999. Patients were divided according to year of introduction of first biological agent. Patient characteristics at introduction of the first biological agent and its effectiveness were analysed over 12 years. RESULTS: 335 patients with non-systemic JIA and 86 patients with systemic JIA started a biological agent between 1999 and 2010. Etanercept remained the most often prescribed biological agent for non-systemic JIA; anakinra became first choice for systemic JIA. The use of systemic glucocorticoids and synthetic disease-modifying antirheumatic drugs before biological agents decreased. During these 12 years of observation, biological agents were prescribed earlier in the disease course and to patients with lower baseline JADAS (Juvenile Arthritis Disease Activity Score) disease activity. All baseline disease activity parameters were lowered in patients with non-systemic JIA. In systemic JIA, prescription patterns changed towards very early introduction of biological agents (median 0.4 years of disease duration) in patients with a low number of joints with active arthritis and high erythrocyte sedimentation rates. These changes for both systemic and non-systemic JIA resulted in more patients with inactive disease after 3 and 15 months of treatment. CONCLUSIONS: Biological agents are increasingly prescribed, earlier in the disease and in patients with JIA with lower disease activity. These changes are accompanied by better short-term disease outcomes.

Effectiveness and safety of a second and third biological agent after failing etanercept in juvenile idiopathic arthritis: results from the Dutch National ABC Register.

OBJECTIVE: To evaluate the effectiveness and safety of switching to a second or third biological agent in juvenile idiopathic arthritis (JIA) after etanercept failure. METHODS: The Arthritis and Biologicals in Children Register aims to include all Dutch JIA patients who have used biological agents. Data on the disease course were used to estimate drug survival with Kaplan-Meier and calculate adverse event (AE) rates. RESULTS: Of 307 biologically naive JIA patients who started etanercept, 80 (26%) switched to a second and 22 (7%) to a third biological agent. During 1030 patient-years of follow-up after the introduction of etanercept, 49 switches to adalimumab, 28 infliximab, 17 anakinra, four abatacept and four trial drugs were evaluated. 84% (95% CI 80% to 88%) of patients who started etanercept as a first biological agent were, after 12 months, still on the drug, compared with 47% (95% CI 35% to 60%) who started a second and 51% (95% CI 26% to 76%) who started a third biological agent. Patients who switched because of primary ineffectiveness continued the second agent less often (32%, 95% CI 12% to 53%). After etanercept failure, drug continuation of adalimumab was similar to infliximab for patients with non-systemic JIA; anakinra was superior to a second TNF-blocker for systemic JIA. AE rates within first 12 months after initiation were comparable for each course and each biological agent. CONCLUSIONS: Switching to another biological agent is common, especially for systemic JIA patients. A second (and third) agent was less effective than the first. The choice of second biological agent by the physician mainly depends on availability and JIA category.

Tumour necrosis factor-blocking agents in persistent oligoarticular juvenile idiopathic arthritis: results from the Dutch Arthritis and Biologicals in Children Register.

OBJECTIVE: Because TNF inhibitors are not approved for persistent oligoarticular JIA (oJIA), although they are used off-label, we evaluated their effectiveness in patients in this category. METHODS: Persistent oJIA patients were selected from the Dutch Arthritis and Biologicals in Children (ABC) register, an ongoing multicentre prospective study that aims to include all Dutch children with JIA using biologic agents. Response was assessed by the JIA core-set disease activity variables and modified Wallace criteria for inactive disease. RESULTS: Until February 2011, 16 persistent oJIA patients (68.8% females) had been included in the register. Median age of onset was 8.4 years [interquartile range (IQR) 2.1-13.5 years]; history of uveitis in 18.8%; ANA-positive 56.3%. All had previously used MTX, and 81.3% had used IA CSs. Median follow-up after the introduction of biologic treatment was 13.7 months (IQR 8.3-16.7 months). Fourteen patients started etanercept and two patients who had active arthritis as well as uveitis started adalimumab. Although patients with persistent oJIA had few affected joints [median of two active joints at the start of biologic (IQR 1-3)], the patient/parent assessments of pain [median visual analogue score (VAS) 51 (IQR 1-64)] and well-being [median VAS 44 (IQR 6-66)] were high. Additionally, their physician evaluated the disease activity as moderately high [median VAS 36 (IQR 4-65)]. After 3 months this decreased to 0 (IQR 0-30) and 63% achieved inactive disease. After 15 months the disease was inactive in 9/10 observed patients. TNF inhibitors were tolerated well. CONCLUSION: TNF blocking agents seem an effective and justifiable option in persistent oJIA when treatment with IA CS injections and MTX has failed.

Treatment choices of paediatric rheumatologists for juvenile idiopathic arthritis: etanercept or adalimumab?

OBJECTIVES: To evaluate differences in baseline characteristics between etanercept- and adalimumab-treated JIA patients and to reveal factors that influence the choice between these TNF inhibitors, which are considered equally effective in the recent ACR recommendations for JIA treatment. METHODS: Biologic-naïve JIA patients with active arthritis who started treatment with adalimumab or etanercept between March 2008 and December 2011 were selected from the Dutch Arthritis and Biologicals in Children register. Baseline characteristics were compared. Focus group interviews with paediatric rheumatologists were performed to evaluate factors determining treatment choices. RESULTS: A total of 193 patients started treatment with etanercept and 21 with adalimumab. Adalimumab-treated patients had longer disease duration prior to the start of biologics (median 5.7 vs 2.0 years) and more often a history of uveitis (71% vs 4%). Etanercept-treated patients had more disability at baseline (median Childhood Health Assessment Questionnaire score 1.1 vs 0.4) and more active arthritis (median number of active joints 6 vs 4). The presence of uveitis was the most important factor directing the choice towards adalimumab. Factors specific for the paediatric population-such as painful adalimumab injections-as well as the physician's familiarity with the drug accounted for the preference for etanercept. CONCLUSION: Although the two TNF inhibitors are considered equally effective, in daily practice etanercept is most often prescribed; adalimumab is mainly preferred when uveitis is present. In choosing the most suitable biologic treatment, paediatric rheumatologists take into account drug and patient factors, considering newly published data and cautiously implementing this into daily care.

The Toll-like receptor 4 agonist MRP8/14 protein complex is a sensitive indicator for disease activity and predicts relapses in systemic-onset juvenile idiopathic arthritis.

BACKGROUND: Analysis of myeloid-related protein 8 and 14 complex (MRP8/14) serum concentrations is a potential new tool to support the diagnosis of systemic-onset juvenile idiopathic arthritis (SJIA) in the presence of fever of unknown origin. OBJECTIVE: To test the ability of MRP8/14 serum concentrations to monitor disease activity in patients with SJIA and stratify patients at risk of relapse. METHODS: Serum concentrations of MRP8/14 in 52 patients with SJIA were determined by a sandwich ELISA. The monitoring of therapeutic regimens targeting interleukin 1 and tumour necrosis factor α, and methotrexate treatment was analysed and diagnostic power to predict flares was tested. RESULTS: MRP8/14 levels were clearly raised in active disease and decreased significantly in response to successful treatments. Serum concentrations of MRP8/14 increased significantly (p<0.001) (mean±95% CI 12.030±3.090 ng/ml) during disease flares compared with patients with inactive disease (864±86 ng/ml). During clinical remission MRP8/14 serum levels of >740 ng/ml predicted disease flares accurately (sensitivity 92%, specificity 88%). MRP8/14 levels correlated well with clinical disease activity, as assessed by physician's global assessment of disease activity (r=0.62), Childhood Health Assessment Questionnaire (r=0.56), active joint count (r=0.46) and with C-reactive protein (r=0.71) and erythrocyte sedimentation rate (r=0.72) (for all p<0.001). CONCLUSION: MRP8/14 serum concentrations correlate closely with response to drug treatment and disease activity and therefore might be an additional measurement for monitoring anti-inflammatory treatment of individual patients with SJIA. MRP8/14 serum concentrations are the first predictive biomarker indicating subclinical disease activity and stratifying patients at risk of relapse during times of clinically inactive disease.

Trio-based whole exome sequencing in patients with suspected sporadic inborn errors of immunity: A retrospective cohort study.

Background: De novo variants (DNVs) are currently not routinely evaluated as part of diagnostic whole exome sequencing (WES) analysis in patients with suspected inborn errors of immunity (IEI). Methods: This study explored the potential added value of systematic assessment of DNVs in a retrospective cohort of 123 patients with a suspected sporadic IEI that underwent patient-parent trio-based WES. Results: A (likely) molecular diagnosis for (part) of the immunological phenotype was achieved in 12 patients with the diagnostic in silico IEI WES gene panel. Systematic evaluation of rare, non-synonymous DNVs in coding or splice site regions led to the identification of 14 candidate DNVs in genes with an annotated immune function. DNVs were found in IEI genes (NLRP3 and RELA) and in potentially novel candidate genes, including PSMB10, DDX1, KMT2C, and FBXW11. The FBXW11 canonical splice site DNV was shown to lead to defective RNA splicing, increased NF-κB p65 signalling, and elevated IL-1ß production in primary immune cells extracted from the patient with autoinflammatory disease. Conclusions: Our findings in this retrospective cohort study advocate the implementation of trio-based sequencing in routine diagnostics of patients with sporadic IEI. Furthermore, we provide functional evidence supporting a causal role for FBXW11 loss-of-function mutations in autoinflammatory disease. Funding: This research was supported by grants from the European Union, ZonMW and the Radboud Institute for Molecular Life Sciences.

Tumour necrosis factor (TNF)-blocking agents in juvenile psoriatic arthritis: are they effective?

OBJECTIVES: To evaluate the effectiveness of tumour necrosis factor (TNF) blockers in juvenile psoriatic arthritis (JPsA). METHODS: The study was a prospective ongoing multicentre, observational study of all Dutch juvenile idiopathic arthritis (JIA) patients using biologicals. The response of arthritis was assessed by American College of Rheumatology (ACR) paediatric response and Wallace inactive disease criteria. The response of psoriatic skin lesions was scored by a 5-point scale. RESULTS: Eighteen JPsA patients (72% female, median age onset 11.1 (range 3.3-14.6) years, 50% psoriatic skin lesions, 39% nail pitting, 22% dactylitis) were studied. The median follow-up time since starting anti-TNFα was 26 (range 3-62) months. Seventeen patients started on etanercept and one started on adalimumab. After 3 months of treatment 83% of the patients achieved ACR30 response, increasing to 100% after 15 months. Inactive disease reached in 67% after 39 months. There was no discontinuation because of inefficacy. Six patients discontinued treatment after a good clinical response. However, five patients flared and restarted treatment, all with a good response. During treatment four patients (two JPsA and two JIA patients with other subtypes) developed de novo psoriasis. In four of the nine patients the pre-existing psoriatic skin lesions improved. CONCLUSION: Anti-TNFα therapy in JPsA seems effective in treating arthritis. However, in most patients the arthritis flared up after treatment discontinuation, emphasising the need to investigate optimal therapy duration. The psoriatic skin lesions did not respond well and four patients developed de novo psoriasis.

An analysis of the costs and treatment success of etanercept in juvenile idiopathic arthritis: results from the Dutch Arthritis and Biologicals in Children register.

OBJECTIVE: To analyse and report the costs and effects of etanercept therapy in patients with JIA. METHODS: Forty-nine JIA patients were evaluated by means of the JIA core set at the start of etanercept and after 3, 15 and 27 months of therapy. At the same time-points, parents of the patients were asked to complete the Health Utility Index Mark 3 (HUI3). Direct medical costs were collected for 1 year before and 27 months after the start of etanercept and compared with gain in utility. RESULTS: Mean total direct medical costs after the start of etanercept were on average 12 478 euros per patient-year compared with 3720 euros before start. The cost analysis showed that three-quarters of total direct medical costs were from etanercept itself. Other direct medical costs, such as costs concerning hospitalization and concomitant medication, decreased compared with the costs in the period before start of etanercept. Especially a great reduction of consultations at the outpatient clinic was seen. Utility was 0.53 before start of etanercept, according to the multi-attribute utility function of the HUI3 on a scale from 0 (dead) to 1 (perfect health). After 27 months, utility was 0.78. In accordance, also all JIA core set response variables improved significantly over 27 months of etanercept treatment. CONCLUSIONS: Although costs of etanercept therapy are substantial, the gain in utility is even more impressive. Considering that these JIA patients were previously refractory to conventional treatment including MTX, and were at risk of long-time disability and pain, costs are justifiable.

Factors associated with treatment response to etanercept in juvenile idiopathic arthritis.

CONTEXT: Since the introduction of biologic therapies, the pharmacological treatment approach for juvenile idiopathic arthritis (JIA) has changed substantially, with achievement of inactive disease as a realistic goal. OBJECTIVE: To determine the response to therapy after initiation of etanercept therapy among patients with JIA and to examine the association between baseline factors and response to etanercept treatment. DESIGN, SETTING, AND PATIENTS: The Arthritis and Biologicals in Children Register, an ongoing prospective observational study since 1999, includes all Dutch JIA patients who used biologic agents. All biologically naive patients who started etanercept before October 2009 were included, with follow-up data to January 2011. Among the 262 patients, 185 (71%) were female, 46 (18%) had systemic-onset, and the median age at initiation of etanercept treatment was 12.4 years. MAIN OUTCOME MEASURES: Excellent response (inactive disease or discontinuation earlier due to disease remission), intermediate response (more than 50% improvement from baseline, but no inactive disease), and poor response (less than 50% improvement from baseline or discontinuation earlier due to ineffectiveness or intolerance) evaluated 15 months after initiation of etanercept. RESULTS: At 15 months after treatment initiation, 85 patients (32%) were considered excellent responders; 92 (36%), intermediate responders; and 85 (32%), poor responders. Compared with an intermediate or poor response, an excellent response was associated with lower baseline disability score (range, 0-3 points, with 0 being the best score; adjusted odds ratio [OR] per point increase, 0.49; 95% CI, 0.33-0.74); fewer disease-modifying antirheumatic drugs (DMARD) (including methotrexate) used before initiating etanercept (adjusted OR per DMARD used, 0.64; 95% CI, 0.43-0.95), and younger age at onset (adjusted OR per year increase, 0.92; 95% CI, 0.84-0.99). Compared with an intermediate or excellent response, a poor response was associated with systemic JIA (adjusted OR systemic vs nonsystemic categories, 2.92; 95% CI, 1.26-6.80), and female sex (adjusted OR female vs male, 2.16; 95% CI, 1.12-4.18). Within the first 15 months of etanercept treatment, 119 patients experienced 1 or more infectious, noninfectious, or serious adverse events, including 37 among those with an excellent response, 36 with an intermediate response, and 46 with a poor response. Within the first 15 months of treatment, 61 patients discontinued etanercept treatment, including 4 with an excellent response, 0 with an intermediate response, and 57 with a poor response. In a secondary analysis of 262 patients with a median follow-up of 35.6 months after initiation of etanercept, a range of 37% to 49% of patients reached inactive disease. The mean adherence to etanercept was 49.2 months (95% CI, 46.4-52.0) for patients with an excellent response after 15 months, 47.5 months (95% CI, 44.9-50.1) for patients with an intermediate response, and 17.4 months (95% CI, 13.6-21.2) for patients with a poor response. CONCLUSIONS: Among patients with JIA who initiated treatment with etanercept, one-third achieved an excellent response, one-third an intermediate response, and one-third a poor response to therapy. Achievement of an excellent response was associated with low baseline disability scores, DMARDs used before initiating etanercept, and younger age at onset of JIA. Achievement of a poor treatment response was associated with systemic JIA and female sex.

Endothelial and Inflammation Biomarker Profiles at Diagnosis Reflecting Clinical Heterogeneity and Serving as a Prognostic Tool for Treatment Response in Two Independent Cohorts of Patients With Juvenile Dermatomyositis.

OBJECTIVE: Juvenile dermatomyositis (DM) is a heterogeneous systemic immune-mediated vasculopathy. This study was undertaken to 1) identify inflammation/endothelial dysfunction-related biomarker profiles reflecting disease severity at diagnosis, and 2) establish whether such biomarker profiles could be used for predicting the response to treatment in patients with juvenile DM. METHODS: In total, 39 biomarkers related to activation of endothelial cells, endothelial dysfunction, and inflammation were measured using multiplex technology in serum samples from treatment-naive patients with juvenile DM from 2 independent cohorts (n = 30 and n = 29). Data were analyzed by unsupervised hierarchical clustering, nonparametric tests with correction for multiple comparisons, and Kaplan-Meier tests with Cox proportional hazards models for analysis of treatment duration. Myositis-specific antibodies (MSAs) were measured in the patients' serum using line blot assays. RESULTS: Severe vasculopathy in patients with juvenile DM was associated with low serum levels of intercellular adhesion molecule 1 (Spearman's rho [rs ] = 0.465, P = 0.0111) and high serum levels of endoglin (rs = -0.67, P < 0.0001). In the discovery cohort, unsupervised hierarchical clustering analysis of the biomarker profiles yielded 2 distinct patient clusters, of which the smaller cluster (cluster 1; n = 8) exhibited high serum levels of CXCL13, CCL19, galectin-9, CXCL10, tumor necrosis factor receptor type II (TNFRII), and galectin-1 (false discovery rate <0.0001), and this cluster had greater severity of muscle disease and global disease activity (each P < 0.05 versus cluster 2). In the validation cohort, correlations between the serum levels of galectin-9, CXCL10, TNFRII, and galectin-1 and the severity of global disease activity were confirmed (rs = 0.40-0.52, P < 0.05). Stratification of patients according to the 4 confirmed biomarkers identified a cluster of patients with severe symptoms (comprising 64.7% of patients) who were considered at high risk of requiring more intensive treatment in the first 3 months after diagnosis (P = 0.0437 versus other cluster). Moreover, high serum levels of galectin-9, CXCL10, and TNFRII were predictive of a longer total treatment duration (P < 0.05). The biomarker-based clusters were not evidently correlated with patients' MSA serotypes. CONCLUSION: Results of this study confirm the heterogeneity of new-onset juvenile DM based on serum biomarker profiles. Patients with high serum levels of galectin-9, CXCL10, TNFRII, and galectin-1 may respond suboptimally to conventional treatment, and may therefore benefit from more intensive monitoring and/or treatment.

Galectin-9 and CXCL10 as Biomarkers for Disease Activity in Juvenile Dermatomyositis: A Longitudinal Cohort Study and Multicohort Validation.

OBJECTIVE: Objective evaluation of disease activity is challenging in patients with juvenile dermatomyositis (DM) due to a lack of reliable biomarkers, but it is crucial to avoid both under- and overtreatment of patients. Recently, we identified 2 proteins, galectin-9 and CXCL10, whose levels are highly correlated with the extent of juvenile DM disease activity. This study was undertaken to validate galectin-9 and CXCL10 as biomarkers for disease activity in juvenile DM, and to assess their disease specificity and potency in predicting the occurrence of flares. METHODS: Levels of galectin-9 and CXCL10 were measured by multiplex immunoassay in serum samples from 125 unique patients with juvenile DM in 3 international cross-sectional cohorts and a local longitudinal cohort. The disease specificity of both proteins was examined in 50 adult patients with DM or nonspecific myositis (NSM) and 61 patients with other systemic autoimmune diseases. RESULTS: Both cross-sectionally and longitudinally, galectin-9 and CXCL10 outperformed the currently used laboratory marker, creatine kinase (CK), in distinguishing between juvenile DM patients with active disease and those in remission (area under the receiver operating characteristic curve [AUC] 0.86-0.90 for galectin-9 and CXCL10; AUC 0.66-0.68 for CK). The sensitivity and specificity for active disease in juvenile DM was 0.84 and 0.92, respectively, for galectin-9 and 0.87 and 1.00, respectively, for CXCL10. In 10 patients with juvenile DM who experienced a flare and were prospectively followed up, continuously elevated or rising biomarker levels suggested an imminent flare up to several months before the onset of symptoms, even in the absence of elevated CK levels. Galectin-9 and CXCL10 distinguished between active disease and remission in adult patients with DM or NSM (P = 0.0126 for galectin-9 and P < 0.0001 for CXCL10) and were suited for measurement in minimally invasive dried blood spots (healthy controls versus juvenile DM, P = 0.0040 for galectin-9 and P < 0.0001 for CXCL10). CONCLUSION: In this study, galectin-9 and CXCL10 were validated as sensitive and reliable biomarkers for disease activity in juvenile DM. Implementation of these biomarkers into clinical practice as tools to monitor disease activity and guide treatment might facilitate personalized treatment strategies.

S100A12 Is Associated with Response to Therapy in Juvenile Idiopathic Arthritis.

OBJECTIVE: Around one-third of patients with juvenile idiopathic arthritis (JIA) fail to respond to first-line methotrexate (MTX) or anti-tumor necrosis factor (TNF) therapy, with even fewer achieving ≥ American College of Rheumatology Pediatric 70% criteria for response (ACRpedi70), though individual responses cannot yet be accurately predicted. Because change in serum S100-protein myeloid-related protein complex 8/14 (MRP8/14) is associated with therapeutic response, we tested granulocyte-specific S100-protein S100A12 as a potential biomarker for treatment response. METHODS: S100A12 serum concentration was determined by ELISA in patients treated with MTX (n = 75) and anti-TNF (n = 88) at baseline and followup. Treatment response (≥ ACRpedi50 score), achievement of inactive disease, and improvement in Juvenile Arthritis Disease Activity Score (JADAS)-10 score were recorded. RESULTS: Baseline S100A12 concentration was measured in patients treated with anti-TNF [etanercept n = 81, adalimumab n = 7; median 200, interquartile range (IQR) 133-440 ng/ml] and MTX (median 220, IQR 100-440 ng/ml). Of the patients in the anti-TNF therapy group, 74 (84%) were also receiving MTX. Responders to MTX (n = 57/75) and anti-TNF (n = 66/88) therapy had higher baseline S100A12 concentration compared to nonresponders: median 240 (IQR 125-615) ng/ml versus 150 (IQR 87-233) ng/ml, p = 0.021 for MTX, and median 308 (IQR 150-624) ng/ml versus 151 (IQR 83-201) ng/ml, p = 0.002, for anti-TNF therapy. Followup S100A12 could be measured in 44/75 MTX-treated patients (34/44 responders) and 39/88 anti-TNF-treated patients (26/39 responders). Responders had significantly reduced S100A12 concentration (MTX: p = 0.031, anti-TNF: p < 0.001) at followup versus baseline. Baseline serum S100A12 in both univariate and multivariate regression models for anti-TNF therapy and univariate analysis alone for MTX therapy was significantly associated with change in JADAS-10. CONCLUSION: Responders to MTX or anti-TNF treatment can be identified by higher pretreatment S100A12 serum concentration levels.

Identification of an Amino Acid Motif in HLA-DRß1 That Distinguishes Uveitis in Patients With Juvenile Idiopathic Arthritis.

OBJECTIVE: Uveitis is a visually debilitating disorder that affects up to 30% of children with the most common forms of juvenile idiopathic arthritis (JIA). The disease mechanisms predisposing only a subgroup of children to uveitis are unknown. This study was undertaken to identify genetic susceptibility loci for uveitis in JIA, using a genome-wide association study in 522 children with JIA. METHODS: Two cohorts of JIA patients with ophthalmologic follow-up data were genotyped. Data were then imputed using a genome-wide imputation reference panel, and an HLA-specific reference panel was used for imputing amino acids and HLA types in the major histocompatibility complex (MHC). After imputation, genome-wide and MHC-specific analyses were performed, and a reverse immunology approach was utilized to model antigen presentation at 13 common HLA-DRß1 alleles. RESULTS: Presence of the amino acid serine at position 11 (serine 11) in HLA-DRß1 was associated with an increased risk of uveitis in JIA patients (odds ratio [OR] 2.60, P = 5.43 × 10-10 ) and was specific to girls (Pfemales = 7.61 × 10-10 versus Pmales = 0.18). Serine 11 resides in the YST motif in the peptide-binding groove of HLA-DRß1; all 3 amino acids in this motif are in perfect linkage disequilibrium and show identical association with disease. Quantitative prediction of binding affinity revealed that HLA-DRß1 alleles with the YST motif could be distinguished on the basis of discernable peptide-binding preferences. CONCLUSION: These findings highlight a genetically distinct, sexually dimorphic feature of JIA with uveitis as compared to JIA without uveitis. The association could be indicative of the potential involvement of antigen presentation by HLA-DRß1 in the development of uveitis in JIA. The results of this study may advance our progress toward improved treatments for, and possible prevention of, the sight-threatening complications of uveitis in children with JIA.

Fludeoxyglucose positron emission tomography-computed tomography scan showing polyarthritis in a patient with an atypical presentation of Henoch-Schönlein vasculitis without clinical signs of arthritis: a case report.

BACKGROUND: Henoch-Schönlein vasculitis is the most common systemic vasculitis in children. Arthritis or arthralgia occurs in 80 % of patients. We believe this to be the first case report to describe the finding of polyarthritis in a fludeoxyglucose positron emission tomography-computed tomography scan in a patient with Henoch-Schönlein vasculitis without clinical signs of arthritis. CASE PRESENTATION: A 4.5-year-old Caucasian boy presented with fever of 4 days' duration followed by debilitating migratory arthralgia and inflammation. He underwent a fludeoxyglucose positron emission tomography-computed tomography scan to exclude a possible malignant cause or to detect any infectious or autoimmune focus of his symptoms. Fludeoxyglucose uptake was observed in multiple large joints and in multiple tendons. These findings suggested active polyarthritis and polytendinitis. However, physical and ultrasound evaluations did not show any signs of arthritis in our patient, despite his evident arthralgia. CONCLUSIONS: Fludeoxyglucose positron emission tomography-computed tomography might be able to detect inflammatory activity in painful joints that cannot yet be detected clinically or with ultrasound evaluation in a patient with Henoch-Schönlein vasculitis. Therefore, fludeoxyglucose positron emission tomography-computed tomography can be of additional value in the diagnostic workup of patients with an unresolved diagnosis of suspected autoimmune disease, especially in patients with unresolved arthralgia and fever of unknown cause.

Protein-losing enteropathy in camptodactyly-arthropathy-coxa vara-pericarditis (CACP) syndrome.

BACKGROUND: Camptodactyly-arthropathy-coxa vara-pericarditis (CACP, OMIM: #208250) syndrome is a rare autosomal recessive disease that can be difficult to recognise not only because of its wide clinical variability but also because of its clinical resemblance to juvenile idiopathic arthritis (JIA). PRG4 is the only gene so far known to be associated with CACP syndrome. Children with CACP syndrome lack the glycoprotein lubricin due to recessive mutations in PRG4. Lubricin serves as a lubricant in joints, tendons and visceral cavities (pleural cavity, pericardium) and inhibits synovial proliferation. Children with CACP syndrome suffer from congenital camptodactyly, arthropathy, coxa vara and sometimes pericarditis. This report concerns a child with CACP syndrome complicated by protein-losing enteropathy (PLE), caused by constrictive pericarditis and so contributes to knowledge of the presentation of CACP syndrome. CASE PRESENTATION: A 10- year-old girl with consanguineous parents suffered from congenital camptodactyly and progressive swollen and painful joints. Her father and his sister had similar childhood-onset joint complaints. Laboratory tests showed no signs of inflammation but showed persistent low protein- and IgG- levels, indicating a secondary immunodeficiency. Increased alpha antitrypsin clearance confirmed PLE. Abdominal ultrasound with Doppler showed hepatomegaly and portal hypertension. Echocardiography suggested constrictive pericarditis. However, heart catheterization could not confirm this. Ultrasound and X-ray examination of the joints combined with a puncture of the synovial fluid were performed. These results, combined with the clinical presentation and the consanguinity, suggested CACP syndrome. Due to excessive enteral protein losses, the patient was treated with Cotrimoxazol prophylaxis and immunoglobulin supplements. These supplements were inadequate to achieve normal IgG values. As constrictive pericarditis with subsequent PLE was the best explanation for the excessive IgG losses, pericardiectomy was performed with good results. Genetic testing in our patient was complicated but revealed a pathogenic mutation within the repeat sequence in exon 7 of the PRG4 gene. CONCLUSION: PLE resulting from constrictive pericarditis can be a complication of CACP syndrome. As serious complications can arise from the resulting secondary immunodeficiency, we recommend regular evaluation of clinical symptoms of constrictive pericarditis and PLE in children with CACP syndrome.