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Objective Somatic mutations in UBA1 cause a newly defined syndrome known as VEXAS (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic syndrome). More than 50% of patients currently identified as having VEXAS met diagnostic criteria for relapsing polychondritis (RP), but clinical features that characterize VEXAS within a cohort of patients with RP have not been defined. We undertook this study to define the prevalence of somatic mutations in UBA1 in patients with RP and to create an algorithm to identify patients with genetically confirmed VEXAS among those with RP. Methods Exome and targeted sequencing of UBA1 was performed in a prospective observational cohort of patients with RP. Clinical and immunologic characteristics of patients with RP were compared based on the presence or absence of UBA1 mutations. The random forest method was used to derive a clinical algorithm to identify patients with UBA1 mutations. Results Seven of 92 patients with RP (7.6%) had UBA1 mutations (referred to here as VEXAS-RP). Patients with VEXAS-RP were all male, were on average ≥45 years of age at disease onset, and commonly had fever, ear chondritis, skin involvement, deep vein thrombosis, and pulmonary infiltrates. No patient with VEXAS-RP had chondritis of the airways or costochondritis. Mortality was greater in VEXAS-RP than in RP (23% versus 4%; P = 0.029). Elevated acute-phase reactants and hematologic abnormalities (e.g., macrocytic anemia, thrombocytopenia, lymphopenia, multiple myeloma, myelodysplastic syndrome) were prevalent in VEXAS-RP. A decision tree algorithm based on male sex, a mean corpuscular volume >100 fl, and a platelet count

Discovery of the VEXAS (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic) syndrome demonstrates that somatic mutations in haematological precursor cells can cause adult-onset, complex inflammatory disease. Unlike germline mutations, somatic mutations occur throughout the lifespan, are restricted to specific tissue types, and may play a causal role in non-heritable rheumatological diseases, especially conditions that start in later life. Improvements in sequencing technology have enabled researchers and clinicians to detect somatic mutations in various tissue types, especially blood. Understanding the relationships between cell-specific acquired mutations and inflammation is likely to yield key insights into causal factors that underlie many rheumatological diseases. The objective of this review is to detail how somatic mutations are likely to be relevant to clinicians who care for patients with rheumatological diseases, with particular focus on the pathogenetic mechanisms of the VEXAS syndrome.

Mouth and genital ulcers with inflamed cartilage (MAGIC) syndrome is characterized by overlapping features of relapsing polychondritis (RP) and Behcet's disease (BD). To date, no studies have defined the clinical spectrum of disease in a cohort of patients with MAGIC syndrome.Adult patients within an ongoing prospective, observational cohort study in RP were clinically assessed for MAGIC syndrome. A systematic review was conducted to identify additional cases of MAGIC syndrome by searching four databases: PubMed (US National Library of Medicine), Embase (Elsevier), Scopus (Elsevier) and Web of Science: Core Collection (Clarivate Analytics). The inclusion criteria used were: [1] patients of any age or gender who were diagnosed with MAGIC syndrome, or both RP and BD; [2] case report or case series study; [3] published from 1985 - July 2020; and [4] in English language. Risk of bias was assessed using a checklist developed by the authors and based on the Consensus-based Clinical Case Reporting (CARE) Guidelines. Search results screening, article inclusion, data extraction and risk of bais assessment was performed independently by two investigators. Clinical characteristics, particularly BD-related features, were compared between patients with MAGIC syndrome and cases of non-MAGIC RP. The performance characteristics of different criteria to classify MAGIC syndrome were also evaluated.Out of 96 patients with RP, 13 (14%) patients were diagnosed with MAGIC syndrome. For the systematic review, 380 articles were retrieved of which 90 were screened at title and abstract levels. Of these screened, 60 were excluded and 30 proceeded to full text review where an additional 8 were excluded. Twenty-two articles were included in our review and from which 27 additional cases of MAGIC syndrome were identified. Pooling all 40 cases together and comparing them with non-MAGIC RP, there was a significantly higher prevalence of ocular involvement (28% vs 4%, p0.01), cutaneous involvement (35% vs 1%, p0.01), GI involvement (23% vs 4%, p0.01), and CNS involvement (8% vs 0, p = 0.04) in MAGIC syndrome. A higher prevalence of aortitis (23% vs 1%, p0.01), Raynaud's phenomenon (54% vs 11%, p0.01), and elevated anti-collagen II antibodies (50% vs 9%, p = 0.04) were observed in MAGIC syndrome. Fulfillment of either McAdam's or Damiani's Criteria for RP plus the International Criteria for Behçet's Disease had excellent sensitivity (98%) to classify cases of MAGIC syndrome.A substantial proportion of patients with RP can be clinically diagnosed with MAGIC syndrome. These patients have features of RP, BD, and other unique features including aortitis, Raynaud's phenomenon and elevated anti-collagen II antibodies.

Objective.To assess patient-reported burden of disease in pediatric patients with relapsing polychondritis (RP) and to compare those findings to adult patients.Methods.A survey based on known clinical symptoms of RP was developed and administered to patients with a pediatric diagnosis of RP. Adult patients completed a similar survey.Results.Twenty-one pediatric patients, or their parents, completed surveys. Median age at symptom onset was 6 years (interquartile range 1.8–12). Prior to diagnosis, most pediatric patients went to the emergency room (ER; 61.9%), saw > 3 physicians (57.1%), and took > 1 year to be diagnosed (61.9%). Pediatric patients were often diagnosed with asthma (42.9%), ear infections (42.9%), or sinusitis (33.3%) prior to diagnosis of RP. Symptoms prior to diagnosis included ear pain/redness (85.7%), joint pain/swelling (61.9%), and airway symptoms (38.1%). Four pediatric patients (19%) reported tracheomalacia requiring tracheostomy. Pediatric patients frequently missed school because of their disease (71.4%). Surveys from 290 adult patients were compared to pediatric patients. Pediatric patients were significantly more likely to undergo biopsy (42.9% vs 17.4%; p < 0.01) and be treated with biologics (42.9% vs 19%; p = 0.02). Adults were significantly more likely to be female (87.8% vs 28.6%; p < 0.01) and to report airway symptoms (77.9% vs 47.6%; p = 0.01). Prevalence of disease complications was not significantly different between adult and pediatric patients.Conclusions.The burden of disease in pediatric patients with RP includes missed school, diagnostic delay, ER visits, and multisystem disease, with resultant damage to cartilaginous structures. Differences in airway involvement and treatment approaches may exist between pediatric and adult patients.

Objective Relapsing polychondritis (RP) is a systemic disease. Failure to recognize RP can lead to diagnostic delay and further complications, including death. This study was undertaken to identify clinical patterns in a prospective cohort of patients with RP. Methods Patient subgroups were identified using latent class analysis based on 8 clinical variables: saddle-nose deformity, subglottic stenosis, tracheomalacia, bronchomalacia, ear chondritis, tenosynovitis/synovitis, inflammatory eye disease, and audiovestibular disease. Model selection was based on Akaike's information criterion. Results Seventy-three patients were included in this study. Patients were classified into 1 of 3 subgroups: type 1 RP (14%), type 2 RP (29%), and type 3 RP (58%). Type 1 RP was characterized by ear chondritis (100%), tracheomalacia (100%), saddle-nose deformity (90%), and subglottic stenosis (80%). These patients had the shortest median time to diagnosis (1 year), highest disease activity, and greatest frequency of admission to the intensive care unit and tracheostomy. Type 2 RP was characterized by tracheomalacia (100%) and bronchomalacia (52%), but no saddle-nose deformity or subglottic stenosis. These patients had the longest median time to diagnosis (10 years) and highest percentage of work disability. Type 3 RP was characterized by tenosynovitis/synovitis (60%) and ear chondritis (55%). There were no significant differences in sex, race, or treatment strategies between the 3 subgroups. Conclusion Our findings indicate that there are 3 subgroups of patients with RP, with differences in time to diagnosis, clinical and radiologic characteristics, and disease-related complications. Recognizing a broader spectrum of clinical patterns in RP, beyond cartilaginous involvement of the ear and upper airway, may facilitate more timely diagnosis.

Objective To determine whether autophagy is involved in the degradation of misfolded HLA-B27 in experimental spondyloarthritis. Methods Bone marrow-derived macrophages from HLA-B27/human β2 -microglobulin (hβ2 m)-transgenic rats were incubated in the presence or absence of interferon-γ and proteasome or autophagy inhibitors. Immunoprecipitation, immunoblotting, and immunofluorescence analysis were used to measure HLA-B27 heavy chains and autophagy. Autophagy was induced using rapamycin. Macrophages from HLA-B7/hβ2 m-transgenic and wild-type rats were used as controls. Results HLA-B27-expressing macrophages showed phosphatidylethanolamine-conjugated microtubule-associated protein 1 light chain 3B levels similar to those in both control groups, before and after manipulation of autophagy. Blocking autophagic flux with bafilomycin resulted in the accumulation of misfolded HLA-B27 dimers and oligomers as well as monomers, which was comparable with the results of blocking endoplasmic reticulum-associated degradation (ERAD) with the proteasome inhibitor bortezomib. HLA-B7 monomers also accumulated after blocking each degradation pathway. The ubiquitin-to-heavy chain ratio was 2-3-fold lower for HLA-B27 than for HLA-B7. Activation of autophagy with rapamycin rapidly eliminated ~50% of misfolded HLA-B27, while folded HLA-B27 or HLA-B7 monomeric heavy chains were minimally affected. Conclusion This study is the first to demonstrate that both autophagy and ERAD play roles in the elimination of excess HLA class I heavy chains expressed in transgenic rats. We observed no evidence that HLA-B27 expression modulated the autophagy pathway. Our results suggest that impaired ubiquitination of HLA-B27 may play a role in the accumulation of misfolded disulfide-linked dimers, the elimination of which can be enhanced by activation of autophagy. Manipulation of the autophagy pathway should be further investigated as a potential therapeutic target in spondyloarthritis.

Background:Somatic mutations in ubiquitin activating enzyme 1 (UBA1) cause a newly defined syndrome known as VEXAS. [1] More than fifty percent of patients currently identified with VEXAS meet diagnostic criteria for relapsing polychondritis (RP).Objectives:To determine the prevalence VEXAS within a cohort of patients with RP, to compare their clinical, laboratory, and immunologic features and to develop a clinical algorithm to inform genetic screening for VEXAS among patients with RP.Methods:Exome and targeted sequencing of the UBA1 gene was performed in a prospective observational cohort of patients with RP. Clinical and immunological characteristics of patients with RP were compared based on presence or absence of UBA1 mutations. Random forest was used to derive a clinical algorithm to identify patients with UBA1 mutations. Immune populations were quantified by multipanel flow cytometry. Categorical and continuous variables were compared using the chi square or Kruskal-Wallis test. PResults:Seven of 92 patients with RP (7.6%) were confirmed to have UBA1 mutations (VEXAS-RP). Six additional patients with VEXAS-RP from other cohorts were included for subsequent analyses. Patients with VEXAS-RP were all male, older at disease onset, and commonly had fever, ear chondritis, skin involvement, deep vein thrombosis, and pulmonary infiltrates. Patients with RP as compared with VEXAS-RP had a significantly higher prevalence of airway chondritis, costochondritis and tenosynovitis/arthralgias. (Table). Mortality was significantly greater in VEXAS-RP than RP (27% vs 2% p=0.01). Maximum ESR, CRP, and mean corpuscular volume (MCV) values were significantly greater in VEXAS-RP. Absolute monocyte, lymphocyte, and platelet counts were significantly lower in VEXAS-RP. A decision tree based on male sex, MCV>100 fl and Platelet countTable 1.Clinical Characteristics of patients with RP vs VEXAS-RPAll Patientsn=98RPn=85VEXAS-RPn=13p valueDemographic CharacteristicsRace, White n (%)90 (92)77 (91)13 (100)0.59Sex, Male n (%)26 (27)13 (15)13 (100)Age, Symptom onset, years, Median (IQR)38 (30-47)37 (28-43)56 (54-64)Clinical SymptomsFever n (%)33 (34)20 (24)13 (100)Ear chondritis n (%)61 (62)48 (56)13 (100)0.0015Nose chondritis n (%)83 (85)71 (84)12 (92)0.68Airway chondritis n (%)37 (38)37 (44)0 (0)0.0015Tenosynovitis/arthalgias n (%)83 (85)77 (91)6 (46)0.0005Skin involvement n (%)33 (34)22 (2611 (85)Laboratory ValuesESR, mm/hr, median (IQR)12 (6-22)11 (5-19)66.5 (42-110)CRP, mg/L, median (IQR)2.9 (0.8-9.6)1.9 (0.6-6.3)17.7 (9.6-99.5)Platelet count (k/uL)246(201-299)258 (227-312)145 (100-169)MCV fL93.05 (90-98)92.2 (89-95)105 (102-115)Absolute lymphocyte count1.6 (1.1-2.3)1.78(1.4-2.4)0.92 (0.5-1.2)CT scan abnormalitiesPulmonary infiltrates n (%)16 (16.33)6 (7.06)10 (77)ComplicationsDeath n (%)6 (6)3 (4)3 (23)0.029Unprovoked DVT12 (12)4 (5)8 (62)N number; IQR = interquartile rangeConclusion:Mutations in UBA1 are causal for disease in a subset of patients with RP. These patients are defined by disease onset in the fifth decade of life or later, male sex, ear/nose chondritis and hematologic abnormalities. Early identification is important in VEXAS given the associated high mortality rate.References:[1]Beck DB, Ferrada MA, Sikora KA, Ombrello AK, Collins JC, Pei W, Balanda N, Ross DL, Ospina Cardona D, Wu Z et al: Somatic Mutations in UBA1 and Severe Adult-Onset Autoinflammatory Disease. N Engl J Med 2020, 383(27):2628-2638.Disclosure of Interests:None declared

Objective To assess patient-reported symptoms and burden of disease in relapsing polychondritis (RP). Methods Patients with RP completed a disease-specific online survey to identify symptoms attributed to illness. Patients were divided into subgroups based upon presence or absence of ear/nose, airway, or joint involvement. Pathway to diagnosis, treatment, and disease-related complications were assessed within each subgroup. Results Data from 304 respondents were included in this analysis. Prior to diagnosis, most patients with RP went to the emergency room (54%), saw >3 physicians (54%), and had symptoms for >5 years (64%). A concomitant diagnosis of fibromyalgia and absence of ear/nose or joint involvement was associated with diagnostic delay >1 year. Common diagnoses prior to RP diagnosis included asthma in patients with airway involvement (35% vs 22%, p=0.03) and ear infection in patients with ear/nose involvement (51% vs 6%, p

Genetic and genomic investigations are a starting point for the study of human disease, seeking to discover causative variants relevant to disease pathophysiology. Over the past 5 years, massively parallel, high-throughput, next-generation sequencing techniques have revolutionized genetics and genomics, identifying the causes of many Mendelian diseases. The application of whole-genome sequencing and whole-exome sequencing to large populations has produced several publicly available sequence datasets that have revealed the scope of human genetic variation and have contributed to important methodological advances in the study of both common and rare genetic variants in genetically complex diseases. The importance of noncoding genetic variation has been highlighted by the Encyclopedia of DNA Elements (ENCODE) project and National Institutes of Health (NIH) Roadmap Epigenomics Program and integrated analyses of these datasets, together with disease-specific datasets, will provide an important and powerful tool for determining the mechanisms through which disease-associated, noncoding variation influences disease risk.

Systemic juvenile idiopathic arthritis (SJIA) is an autoinflammatory disease characterized by spiking fevers, arthritis, polyserositis, evanescent rash, and lymphadenopathy (1). Evidence suggests that one of the effector cells in the pathogenesis of this disease is of the monocyte/macrophage lineage. Patients with active SJIA not only have an increased proportion of CD14+ monocytes (2), but also increased myelomonocytic precursors within their peripheral blood (3,4). In addition, one of the feared complications of SJIA is the macrophage activation syndrome (MAS) where affected patients experience widespread activation and expansion of T lymphocytes and cells of the monocyte-macrophage lineage, leading to unremitting fever, hyperferritinemia, hypertriglyceridemia, hepatosplenomegaly, a consumptive coagulopathy, and cytopenias. One of its prominent characteristics is an expansion of macrophages actively engaged in the hemophagocytosis of multiple cellular elements within the bone marrow and other lymphoid tissue (5,6). Yet, many of these features can be appreciated in severe SJIA too, in an intermediate phenotype called subclinical or occult MAS, thus suggesting MAS and SJIA may be different extremes of the same clinical spectrum (7,8). The activated macrophage phenotype can be divided into two general groups, M1 and M2, depending on the stimuli they receive and their subsequent differentiation pathway (9–11). In this model, M1 macrophage differentiation is mainly driven by interferon-γ (IFN-γ) and M2 macrophages result from mostly anti-inflammatory signals, such as IL-4, IL-10, M-CSF, TGF-β, or glucocorticoids. M1 macrophages excel at intracellular pathogen eradication, producing high amounts of IL-12 and TNF-α. Due to their highly phagocytic properties, M2 macrophages are mostly scavengers that are heavily involved in wound healing and tissue remodeling. In contrast to M1 macrophages, M2 macrophages are a prominent source of IL-10. Currently, the activated macrophage in SJIA and MAS has yet to be characterized into the M1/M2 polar model. SJIA and MAS are both inflammatory conditions, thus it’s likely that the macrophages therein are of the M1 phenotype. However, the data supporting IFN-γ, which is the key facilitator of M1 macrophage differentiation, as a mediator in active SJIA is scant. Gattorno et al. demonstrated elevated serum levels of both IFN-γ and IP-10, regardless of disease activity (12). In contrast, Lasiglie at al. showed that upon overnight stimulation of PBMC populations, no difference in the absolute number of IFN-γ-producing cells between active SJIA patients and healthy controls could be appreciated (13). Congruent with this finding, three independent gene expression studies have failed to detect an IFN-induced genetic signature within the peripheral blood mononuclear cells (PBMCs) of active SJIA patients (3,14,15). In contrast to SJIA, IFN-γ is believed to have a prominent role in the pathogenesis of hemophagocytic lymphohistiocytosis (HLH), both a hereditary and acquired hemophagocytic syndrome clinically similar to MAS, where IFN-γ is found to be highly elevated in the serum (16–18). In fact, blockade of IFN-γ has been suggested as a potential treatment for both inherited and acquired forms of active HLH (19). To this end, the goals of this study were to characterize the status of an IFN-induced signature within affected tissues and to gauge the integrity of IFN-signaling pathways within the peripheral monocytes of patients with SJIA. IFN-γ is a pleotropic cytokine that canonically signals via the Janus kinase (Jak)-signal transducer and activator of transcription (STAT) pathway, machinery that is common to the many different cytokines (20). Specifically, IFN-γ will lead to the recruitment of Jak1 and Jak2 to the intracellular portion of the IFN-γ receptor, which then becomes phosphorylated on a tyrosine residue. This allows recruitment, docking, and subsequent phosphorylation of STAT1. In its active form, STAT1 will then form a homodimer and translocate into the nucleus in order to bind to a promoter region IFN-γ activation site (GAS) to initiate specific IFN-responsive genes. Given the inflammatory nature of active SJIA, it seems paradoxical that an IFN-induced genetic signature cannot be detected within the PBMCs of active SJIA. In this study, we explore the role of IFN-γ in the pathogenesis of SJIA. We confirm a restricted IFN-induced genetic signature in not only the peripheral mononuclear cells, but also isolated peripheral monocytes therein. Furthermore, we demonstrate a markedly constrained expression of IFN-responsive genes within peripherally affected SJIA synovial tissue in comparison to extended oligoarticular JIA, a subtype of JIA that is known to express an IFN-induced genetic signature within its synovial cells (21). Upon exploring the ability of SJIA peripheral monocytes to even respond to IFN-γ, we did not find their overall reactivity to be significantly different from healthy control peripheral monocytes, which suggests that the absence of an IFN-induced genetic signature is not due to monocyte hyporesponsiveness to IFN-γ, but likely due to a limited exposure to it. Finally, we also report an increased basal interferon signal and augmented reactivity to IFN-γ within the peripheral monocytes of inactive SJIA patients on an IL-1β blocking agent, a finding that may have an impact on the ability of these patients to appropriately respond to viral illnesses.