"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.

Curation and expansion of the Human Phenotype Ontology for systemic autoinflammatory diseases improves phenotype-driven disease-matching.

Introduction: Accurate and standardized phenotypic descriptions are essential in diagnosing rare diseases and discovering new diseases, and the Human Phenotype Ontology (HPO) system was developed to provide a rich collection of hierarchical phenotypic descriptions. However, although the HPO terms for inborn errors of immunity have been improved and curated, it has not been investigated whether this curation improves the diagnosis of systemic autoinflammatory disease (SAID) patients. Here, we aimed to study if improved HPO annotation for SAIDs enhanced SAID identification and to demonstrate the potential of phenotype-driven genome diagnostics using curated HPO terms for SAIDs. Methods: We collected HPO terms from 98 genetically confirmed SAID patients across eight different European SAID expertise centers and used the LIRICAL (Likelihood Ratio Interpretation of Clinical Abnormalities) computational algorithm to estimate the effect of HPO curation on the prioritization of the correct SAID for each patient. Results: Our results show that the percentage of correct diagnoses increased from 66% to 86% and that the number of diagnoses with the highest ranking increased from 38 to 45. In a further pilot study, curation also improved HPO-based whole-exome sequencing (WES) analysis, diagnosing 10/12 patients before and 12/12 after curation. In addition, the average number of candidate diseases that needed to be interpreted decreased from 35 to 2. Discussion: This study demonstrates that curation of HPO terms can increase identification of the correct diagnosis, emphasizing the high potential of HPO-based genome diagnostics for SAIDs.

Discontinuation of biologic DMARDs in non-systemic JIA patients: a scoping review of relapse rates and associated factors.

BACKGROUND: Biologic disease-modifying antirheumatic drugs (bDMARDs) have changed the treatment of juvenile idiopathic arthritis (JIA) patients notably, as bDMARDs enable substantially more patients to achieve remission. When sustained remission is achieved, tapering or even discontinuation of the bDMARD is advocated, to reduce side effects and costs. However, when and how to discontinue bDMARD therapy and what happens afterwards, is less known. OBJECTIVES: With this scoping review we aim to collect available data in current literature on relapse rate, time to relapse (TTR) and possible flare associated variables (such as time spent in remission and method of discontinuation) after discontinuing bDMARDs in non-systemic JIA patients. METHODS: We performed a literature search until July 2022 using the Pubmed database. All original studies reporting on bDMARD discontinuation in non-systemic JIA patients were eligible. Data on patient- and study characteristics, the applied discontinuation strategy, relapse rates and time to relapse were extracted in a standardized template. RESULTS: Of the 680 records screened, 28 articles were included in this review with 456 non-systemic JIA patients who tapered and/or stopped bDMARD therapy. Relapse rate after discontinuation of bDMARDs, either abruptly or following tapering, were 40-48%, 36.8-45.0% and 60-78% at 6, 8 and 12 months respectively. Total relapse rate ranged from 26.3% to 100%, with mean time to relapse (TTR) of 2 to 8.4 months, median TTR 3 to 10 months. All studies stated a good response after restart of therapy after flare. JIA subtype, type of bDMARD, concomitant methotrexate use, treatment duration, tapering method, age, sex, and time in remission could not conclusively be related to relapse rate or TTR. However, some studies reported a positive correlation between flare and antinuclear antibodies positivity, younger age at disease onset, male sex, disease duration and delayed remission, which were not confirmed in other studies. CONCLUSION: Flares seem to be common after bDMARD discontinuation, but little is known about which factors influence these flares in JIA patients. Follow up after discontinuation with careful registration of patient variables, information about tapering methods and flare rates are required to better guide tapering and/or stopping of bDMARDs in JIA patients in the future.

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.

3D stereophotogrammetry in children and adolescents with Scleroderma En Coup De Sabre/Parry-Romberg Syndrome: Description of a novel method for monitoring disease progression.

Background: The diagnosis of Scleroderma En Coup de Sabre (ECDS)/Parry Romberg Syndrome (PRS) is mainly based on characteristic clinical findings. Methods to objectively monitor the course of the disease in a standardized way are lacking. Objectives: This descriptive, retrospective, single centre cohort study aims to describe the contribution of 3D photographs in the assessment of the degree of facial asymmetry changes over time in growing children and adolescents with ECDS and PRS. Methods: Six patients diagnosed with ECDS/PRS, with a follow-up period of at least 24 months and at least three 3D photographs were included. Mirroring these 3D photographs was automatically performed using surface-based matching to generate a colour-coded distance map, illustrating the inter-surface distance and thereby asymmetry between the original and mirrored 3D photographs. The percentage of absolute distances between the original and mirrored 3D photograph were calculated. Results: In two patients, impressive decreases in the percentages of absolute distance levels over time were found, whereas the other patients did not show progression of asymmetry over time. Conclusion: This study shows the potential of 3D stereophotogrammetry as an objective tool to measure disease activity over time in patients with ECDS/PRS.

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.

Curation and expansion of Human Phenotype Ontology for defined groups of inborn errors of immunity.

BACKGROUND: Accurate, detailed, and standardized phenotypic descriptions are essential to support diagnostic interpretation of genetic variants and to discover new diseases. The Human Phenotype Ontology (HPO), extensively used in rare disease research, provides a rich collection of vocabulary with standardized phenotypic descriptions in a hierarchical structure. However, to date, the use of HPO has not yet been widely implemented in the field of inborn errors of immunity (IEIs), mainly due to a lack of comprehensive IEI-related terms. OBJECTIVES: We sought to systematically review available terms in HPO for the depiction of IEIs, to expand HPO, yielding more comprehensive sets of terms, and to reannotate IEIs with HPO terms to provide accurate, standardized phenotypic descriptions. METHODS: We initiated a collaboration involving expert clinicians, geneticists, researchers working on IEIs, and bioinformaticians. Multiple branches of the HPO tree were restructured and extended on the basis of expert review. Our ontology-guided machine learning coupled with a 2-tier expert review was applied to reannotate defined subgroups of IEIs. RESULTS: We revised and expanded 4 main branches of the HPO tree. Here, we reannotated 73 diseases from 4 International Union of Immunological Societies-defined IEI disease subgroups with HPO terms. We achieved a 4.7-fold increase in the number of phenotypic terms per disease. Given the new HPO annotations, we demonstrated improved ability to computationally match selected IEI cases to their known diagnosis, and improved phenotype-driven disease classification. CONCLUSIONS: Our targeted expansion and reannotation presents enhanced precision of disease annotation, will enable superior HPO-based IEI characterization, and hence benefit both IEI diagnostic and research activities.

A clinical prediction model for estimating the risk of developing uveitis in patients with juvenile idiopathic arthritis.

OBJECTIVE: To build a prediction model for uveitis in children with JIA for use in current clinical practice. METHODS: Data from the international observational Pharmachild registry were used. Adjusted risk factors as well as predictors for JIA-associated uveitis (JIA-U) were determined using multivariable logistic regression models. The prediction model was selected based on the Akaike information criterion. Bootstrap resampling was used to adjust the final prediction model for optimism. RESULTS: JIA-U occurred in 1102 of 5529 JIA patients (19.9%). The majority of patients that developed JIA-U were female (74.1%), ANA positive (66.0%) and had oligoarthritis (59.9%). JIA-U was rarely seen in patients with systemic arthritis (0.5%) and RF positive polyarthritis (0.2%). Independent risk factors for JIA-U were ANA positivity [odds ratio (OR): 1.88 (95% CI: 1.54, 2.30)] and HLA-B27 positivity [OR: 1.48 (95% CI: 1.12, 1.95)] while older age at JIA onset was an independent protective factor [OR: 0.84 (9%% CI: 0.81, 0.87)]. On multivariable analysis, the combination of age at JIA onset [OR: 0.84 (95% CI: 0.82, 0.86)], JIA category and ANA positivity [OR: 2.02 (95% CI: 1.73, 2.36)] had the highest discriminative power among the prediction models considered (optimism-adjusted area under the receiver operating characteristic curve = 0.75). CONCLUSION: We developed an easy to read model for individual patients with JIA to inform patients/parents on the probability of developing uveitis.

INSAID Variant Classification and Eurofever Criteria Guide Optimal Treatment Strategy in Patients with TRAPS: Data from the Eurofever Registry.

BACKGROUND: TNF receptor-associated periodic syndrome (TRAPS) is a rare autoinflammatory disease caused by dominant mutation of the TNF super family receptor 1A (TNFRSF1A) gene. Data regarding long-term treatment outcomes are lacking. OBJECTIVE: To assess correlations of genotype-phenotypes in patients with TRAPS, as defined by the International Study Group for Systemic Autoinflammatory Diseases (INSAID) classification and Eurofever criteria, with treatment responses. METHODS: Data from 226 patients with variants of the TNFRSF1A gene and enrolled in the Eurofever registry were classified according to the INSAID classification in groups A (pathogenic or likely pathogenic variants), B (variants of uncertain significance or not classified variants), and C (benign or likely benign variants) and screened for Eurofever criteria. RESULTS: In group A (127 of 226 patients, 56%), all fulfilled Eurofever criteria and 20 of 127 patients (16%) developed AA amyloidosis. In group B (78 of 226 patients, 35%), 40 of 78 patients (51%) did not fulfill Eurofever criteria, displaying a lower incidence of abdominal pain (P < .02) and higher efficacy rate of on-demand nonsteroidal anti-inflammatory drugs (P < .02) and colchicine (P < .001). Group C (21 of 226 patients, 9%) presented a milder disease (P < .02) and none fulfilled Eurofever criteria. Anti-IL-1 drugs were the most frequently used in patients fulfilling Eurofever criteria, with the highest efficacy rate (>85% complete response). No patients on anti-IL-1 treatments developed AA amyloidosis, and 7 women with a history of failure to conceive had successful pregnancies. CONCLUSION: Anti-IL-1 drugs are the best maintenance treatment in patients with TRAPS. The diagnosis of TRAPS should be considered very carefully in patients of group B not fulfilling Eurofever criteria and group C, and colchicine may be preferable as the first maintenance treatment.

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.

Phenotypic variability including Behçet's disease-like manifestations in DADA2 patients due to a homozygous c.973-2A>G splice site mutation.

OBJECTIVES: To describe phenotypic and functional characteristics of patients with the homozygous c.973-2A>G splice site mutation in the adenosine deaminase 2 (ADA2) gene (rs139750129), resulting in deficiency of ADA2 (DADA2). METHODS: We present case synopses of six patients from three unrelated families. Clinical data were analysed and next-generation sequencing (NGS) was performed. We also tested for aberrant RNA splicing and measured ADA2 enzyme activity. RESULTS: One family had common DADA2 symptoms, whereas Behçet's disease-like manifestations were observed in the other two families. We detected the homozygous c.973-2A>G splice site mutation in ADA2 in all patients tested. ADA2 enzyme activity was significantly lower in patients than in healthy controls, but no correlation between ADA2 activity levels and disease severity was observed. Aberrant splicing was detected in a minority of mRNA transcripts, but the formation of other, undetected, aberrant splicing products could not be excluded. Patients were treated with TNF-α inhibitors to prevent recurrence of inflammatory findings including cerebral vasculitis-associated stroke. CONCLUSIONS: We describe three families with the same homozygous splice site mutation in ADA2 and observed a novel combination of manifestations resembling Behçet's disease. This further expands the range of phenotypes caused by ADA2 mutations, although no complete genotype-phenotype association could be determined. Even without active disease, the risk of stroke should be addressed in making decisions regarding treatment of DADA2 patients.

Exome sequencing in routine diagnostics: a generic test for 254 patients with primary immunodeficiencies.

BACKGROUND: Diagnosis of primary immunodeficiencies (PIDs) is complex and cumbersome yet important for the clinical management of the disease. Exome sequencing may provide a genetic diagnosis in a significant number of patients in a single genetic test. METHODS: In May 2013, we implemented exome sequencing in routine diagnostics for patients suffering from PIDs. This study reports the clinical utility and diagnostic yield for a heterogeneous group of 254 consecutively referred PID patients from 249 families. For the majority of patients, the clinical diagnosis was based on clinical criteria including rare and/or unusual severe bacterial, viral, or fungal infections, sometimes accompanied by autoimmune manifestations. Functional immune defects were interpreted in the context of aberrant immune cell populations, aberrant antibody levels, or combinations of these factors. RESULTS: For 62 patients (24%), exome sequencing identified pathogenic variants in well-established PID genes. An exome-wide analysis diagnosed 10 additional patients (4%), providing diagnoses for 72 patients (28%) from 68 families altogether. The genetic diagnosis directly indicated novel treatment options for 25 patients that received a diagnosis (34%). CONCLUSION: Exome sequencing as a first-tier test for PIDs granted a diagnosis for 28% of patients. Importantly, molecularly defined diagnoses indicated altered therapeutic options in 34% of cases. In addition, exome sequencing harbors advantages over gene panels as a truly generic test for all genetic diseases, including in silico extension of existing gene lists and re-analysis of existing data.

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.

Transient left bundle branch block and left ventricular dysfunction in a patient with NLRP1-associated autoinflammation with arthritis and dyskeratosis syndrome.

The NLRP1-associated autoinflammation with arthritis and dyskeratosis syndrome is a rare novel autoinflammatory disorder. Cardiac involvement has not been previously reported. We present a 12-year-old girl with NLRP1-associated autoinflammation with arthritis and dyskeratosis syndrome who was diagnosed with severely impaired left ventricular function and complete left bundle branch block during an exacerbation of the disease. Cardiac dysfunction proved to be rapidly reversible after initiation of high-dose methylprednisolone.

Decreased quality of life and societal impact of cryopyrin-associated periodic syndrome treated with canakinumab: a questionnaire based cohort study.

BACKGROUND: Cryopyrin-associated periodic syndrome (CAPS) is a rare disease. Knowledge on the quality of life (QoL) and the disease's societal impact is limited. Canakinumab is used in increasing frequency for the treatment of CAPS. METHODS: Observational study in Dutch CAPS patients. Patients completed questionnaires regarding treatment with canakinumab at baseline and retrospectively. Quality of life was assessed using the EQ-5D-5L in adults and CHQ-PF50 in children. Impact on work and school was assessed. Caregivers' quality of life was assessed using the CarerQol. RESULTS: Mean quality of life scores during treatment with canakinumab were 0.769 (EQ-5D-5L), 51.1 (CHQ-P) and 57-1 (CHQ-M). Most patients experienced problems on the pain/discomfort dimension. Higher disease activity and the presence of complications negatively influenced QoL. Half of the patients with a paid job reported absenteeism from work due to CAPS, for an average of 8.7 days in a 4-week period. All schoolgoing patients (N = 5) reported absence from school due to CAPS, for an average of 2.9 days. Caregivers reported gaining a lot fulfillment from providing care for their family members. CONCLUSION: QoL during treatment is lower than in the general Dutch population. CAPS leads to productivity loss and absenteeism from school, and impacts the quality of life in informal caregivers.

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.

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.

A new autoinflammatory and autoimmune syndrome associated with NLRP1 mutations: NAIAD (NLRP1-associated autoinflammation with arthritis and dyskeratosis).

OBJECTIVES: Inflammasomes are multiprotein complexes that sense pathogens and trigger biological mechanisms to control infection. Nucleotide-binding oligomerisation domain-like receptor (NLR) containing a PYRIN domain 1 (NLRP1), NLRP3 and NLRC4 plays a key role in this innate immune system by directly assembling in inflammasomes and regulating inflammation. Mutations in NLRP3 and NLRC4 are linked to hereditary autoinflammatory diseases, whereas polymorphisms in NLRP1 are associated with autoimmune disorders such as vitiligo and rheumatoid arthritis. Whether human NLRP1 mutation is associated with autoinflammation remains to be determined. METHODS: To search for novel genes involved in systemic juvenile idiopathic arthritis, we performed homozygosity mapping and exome sequencing to identify causative genes. Immunoassays were performed with blood samples from patients. RESULTS: We identified a novel disease in three patients from two unrelated families presenting diffuse skin dyskeratosis, autoinflammation, autoimmunity, arthritis and high transitional B-cell level. Molecular screening revealed a non-synonymous homozygous mutation in NLRP1 (c.2176C>T; p.Arg726Trp) in two cousins born of related parents originating from Algeria and a de novo heterozygous mutation (c.3641C>G, p.Pro1214Arg) in a girl of Dutch origin. The three patients showed elevated systemic levels of caspase-1 and interleukin 18, which suggested involvement of NLRP1 inflammasome. CONCLUSIONS: We demonstrate the responsibility of human NLRP1 in a novel autoinflammatory disorder that we propose to call NAIAD for NLRP1-associated autoinflammation with arthritis and dyskeratosis. This disease could be a novel autoimmuno-inflammatory disease combining autoinflammatory and autoimmune features. Our data, combined with that in the literature, highlight the pleomorphic role of NLRP1 in inflammation and immunity. TRIAL REGISTRATION NUMBER: NCT02067962; Results.