Somatic Mutations in UBA1 Define a Distinct Subset of Relapsing Polychondritis Patients With VEXAS

Somatic mutations in autoinflammatory and autoimmune disease

Somatic mutations (also known as acquired mutations) are emerging as common, age-related processes that occur in all cells throughout the body. Somatic mutations are canonically linked to malignant processes but over the past decade have been increasingly causally connected to benign diseases including rheumatic conditions. Here we outline the contribution of somatic mutations to complex and monogenic immunological diseases with a detailed review of unique aspects associated with such causes. Somatic mutations can cause early- or late-onset rheumatic monogenic diseases but also contribute to the pathogenesis of complex inflammatory and immune-mediated diseases, affect disease progression and define new clinical subtypes. Although even variants with a low variant allele fraction can be pathogenic, clonal dynamics could lead to changes over time in the proportion of mutant cells, with possible phenotypic consequences for the individual. Thus, somatic mutagenesis and clonal expansion have relevant implications in genetic testing and counselling. On the basis of both increased recognition of somatic diseases in clinical practice and improved technical and bioinformatic processes, we hypothesize that there will be an ever-expanding list of somatic mutations in various genes leading to inflammatory conditions, particularly in late-onset disease.

Role of allogeneic hematopoietic cell transplantation in VEXAS syndrome

VEXAS (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic) is a newly diagnosed syndrome comprising severe systemic inflammatory and hematological manifestations including myelodysplastic syndrome and plasma cell dyscrasia. Since its discovery four years ago, several groups have identified pleomorphic clinical phenotypes, but few effective medical therapies exist which include Janus Kinase (JAK) inhibitors, interleukin inhibitors (IL-1 and IL-6), and hypomethylating agents. Prospective trials are lacking at this time and most patients remain corticosteroid dependent. VEXAS has a high morbidity from frequent life threatening inflammatory symptoms and risk of progression to hematological malignancies and has an overall survival of 50% at 10 years. Allogeneic stem cell transplant (allo-HCT) is a curative option for this disease caused by somatic mutations in the UBA1 gene. Here we outline the role of allo-HCT in treating patients with VEXAS syndrome, highlighting the outcomes from several single-institution studies and case reports. Prospective trials will be required to precisely define the role of allo-HCT in the management of VEXAS syndrome.

VEXAS syndrome: an adult-onset autoinflammatory disorder with underlying somatic mutation

PURPOSE OF REVIEW

VEXAS syndrome (Vacuoles, E1 enzyme, X-linked, Autoinflammatory, Somatic) was first described in 2020, where in a cohort of adults with unexplained fever or inflammation, systematic genetic testing was performed and 25 men with a median age of 64 years and somatic mutations in the UBA1 gene were identified. In the current review, we aim to discuss the relevant literature from January 2023 until July 2024 to give new insights into the pathophysiology, epidemiology, diagnosis and treatment of VEXAS.

RECENT FINDINGS

VEXAS affects 1 : 4269 in men over the age of 50. Janus-Kinase-inhibitors (JAKi) and IL-6-inhibitors are more effective immunosuppressants against hyperinflammation. Ruxolitinib is more effective than other JAKi. Azacitidine induces remission in many patients, but only few MDS-associated patients were treated. Allogeneic stem cell transplantation is feasible for selected cases. Infections are the major cause of death. Prognosis is still poor with a 5-year mortality rate of 18-40%.

SUMMARY

In the current review, we discuss the novelties for VEXAS, including pathogenic pathways, epidemiological data, diagnostic criteria and algorithms, treatment options and complications. We hope that this review may improve rheumatologists understanding of VEXAS. We strongly recommend enrolling VEXAS patients in registries and clinical trials, to improve prognosis of VEXAS in the future.

Unexplained fever with consumptive syndrome in the elderly: two cases of VEXAS syndrome with inflammasome dysregulation

The aim of this study is to investigate the inflammasome dysregulation in peripheral blood leukocytes of VEXAS patients. The constitutive and in vitro triggered activation of inflammasome in PBMC and neutrophils was analyzed in two Brazilian patients with typical UBA1 mutations, and compared with healthy donors. Our findings highlight the constitutive activation of caspase-1 in VEXAS leukocytes, accompanied by increased plasma levels of IL-18. Furthermore, upon stimulation of isolated peripheral blood mononuclear cells (PBMC) and neutrophils, we observed not only the exhaustion of NLRP3 and NLRP1/CARD8 pathways in VEXAS PBMC but also a significant increase in NLRP3-mediated NETs release in VEXAS neutrophils. These findings support previous studies on the contribution of the inflammasome to VEXAS pathogenesis, identifying at least two profoundly affected pathways (NLRP3 and NLRP1/CARD8) in VEXAS peripheral blood.

Rare primary vasculitis: update on multiple complex diseases and the new kids on the block

Systemic vasculitis is a group of rare diseases that share an essential characteristic: inflammation of blood vessel walls. This injury occurs during the disease course, but specific features vary for each entity. In this paper, we will address relevant aspects of the newest monogenic mutation vasculitis, such as deficiency of adenosine deaminase 2 (ADA2) and VEXAS syndrome (UBA1), and other relevant vasculitis, such as Cogan syndrome and Susac syndrome that may share some similarities with them.

Description of a novel splice site variant in UBA1 gene causing VEXAS syndrome

OBJECTIVE

Vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic (VEXAS) syndrome is a complex immune disorder consequence of somatic UBA1 variants. Most reported pathogenic UBA1 variants are missense or splice site mutations directly impairing the translational start site at p.Met41, with recent studies showing that these variants are frequent causes of recurrent inflammation in older individuals. Here we aimed to characterize a novel UBA1 variant found in two patients clinically presenting with VEXAS syndrome.

METHODS

Patients' data were collected from direct assessments and from their medical charts. Genomics analyses were undertaken by both Sanger and amplicon-based deep sequencing, and mRNA studies were undertaken by both cDNA subcloning and mRNA sequencing.

RESULTS

We report a novel, somatic variant in a canonical splice site of the UBA1 gene (c.346-2A>G), which was identified in two unrelated adult male patients with late-onset, unexplained inflammatory manifestations including recurrent fever, Sweet syndrome-like neutrophilic dermatosis, and lung inflammation responsive only to glucocorticoids. RNA analysis of the patients' samples indicated aberrant mRNA splicing leading to multiple in-frame transcripts, including a transcript retaining the full sequence of intron 4 and a different transcript with the deletion of the first 15 nucleotides of exon 5.

CONCLUSION

Here we describe abnormal UBA1 transcription as a consequence of the novel c.346-2A>G variant, identified in two patients with clinical features compatible with VEXAS syndrome. Overall, these results further demonstrate the expanding spectrum of variants in UBA1 leading to pathology and provide support for a complete gene evaluation in those patients considered candidates for VEXAS syndrome.

VEXAS syndrome (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic): clinical review in a rapidly emerging field

VEXAS syndrome is a recently described entity characterized by systemic inflammatory and hematologic manifestations. The disease was first characterized by Beck et al. in 2020 in a study characterizing 25 patients with undiagnosed adult-onset inflammatory syndromes. While the literature regarding VEXAS syndrome has grown exponentially since 2020, there is still much to be understood. This lack of information leads to challenges in both the diagnosis and treatment of patients with VEXAS syndrome. Patients will often have a variety of clinical symptoms that can lead to missed or delayed diagnoses. Additionally, awareness of VEXAS syndrome is still developing among clinicians. In this comprehensive review, we summarize the current literature regarding VEXAS syndrome, and explore clinical updates of this emerging disease state. Our aim of this review is to increase awareness regarding this new disease state and identify research areas to better understand future treatment approaches for patients with VEXAS syndrome.

A vexing case of a 73-year-old man with fevers, orbital cellulitis, and asymptomatic interstitial lung disease

VEXAS (Vacuoles, E1 enzyme, X-linked, Autoinflammatory, Somatic) syndrome is a rare and recently identified disease resulting from a somatic mutation in the X-linked UBA1 gene in cells of myeloid lineage. It can present in a myriad of ways with the potential to affect various organ systems, including the lungs. VEXAS is usually steroid responsive, but no strong data exists for the use of a steroid-sparing agent. There is limited emerging evidence for haematopoietic stem cell transplantation in a select number of cases. Regardless, prognosis for this condition is poor and a treatment algorithm remains a priority. Herein, we present a case of VEXAS that came to attention with discovery of a relatively asymptomatic interstitial lung disease and led to recurrent febrile episodes with evolving multi-organ involvement.

Population Diversity at the Single-Cell Level

Population-scale single-cell genomics is a transformative approach for unraveling the intricate links between genetic and cellular variation. This approach is facilitated by cutting-edge experimental methodologies, including the development of high-throughput single-cell multiomics and advances in multiplexed environmental and genetic perturbations. Examining the effects of natural or synthetic genetic variants across cellular contexts provides insights into the mutual influence of genetics and the environment in shaping cellular heterogeneity. The development of computational methodologies further enables detailed quantitative analysis of molecular variation, offering an opportunity to examine the respective roles of stochastic, intercellular, and interindividual variation. Future opportunities lie in leveraging long-read sequencing, refining disease-relevant cellular models, and embracing predictive and generative machine learning models. These advancements hold the potential for a deeper understanding of the genetic architecture of human molecular traits, which in turn has important implications for understanding the genetic causes of human disease.

Efficient detection of somatic UBA1 variants and clinical scoring system predicting patients with variants in VEXAS syndrome

OBJECTIVES

To efficiently detect somatic UBA1 variants and establish a clinical scoring system predicting patients with pathogenic variants in VEXAS (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic) syndrome.

METHODS

Eighty-nine Japanese patients with clinically suspected VEXAS syndrome were recruited [81 males and 8 females; median age of onset 69.3 years (interquartile range 62.1-77.6)]. Peptide nucleic acid-clamping PCR (PNA-PCR), regular PCR targeting exon 3 clustering UBA1 variants and subsequent Sanger sequencing were conducted for variant screening. Partitioning digital PCR or targeted amplicon deep sequencing was also performed to evaluate the variant allele frequency (VAF). We developed our clinical scoring system to predict UBA1 variant-positive and -negative patients and assessed the diagnostic value of our system using receiver operating characteristics (ROC) curve analysis.

RESULTS

Forty patients (44.9%) with reported pathogenic UBA1 variants were identified, including a case having a variant with VAF of 1.7%, using a highly sensitive method. Our clinical scoring system considering age >50 years, cutaneous lesions, lung involvement, chondritis and macrocytic anaemia efficiently predicted patients with UBA1 variants (the area under the curve for the scoring total was 0.908).

CONCLUSION

Genetic screening with the combination of regular PCR and PNA-PCR detected somatic UBA1 variants with high sensitivity and specificity. Our scoring system could efficiently predict patients with UBA1 variants.

VEXAS syndrome: An update

VEXAS (Vacuoles, E1 Enzyme, X-linked, Autoinflammatory, Somatic) syndrome is a recently described autoinflammatory syndrome, mostly affecting men older than 50 years, caused by somatic mutation in the UBA1 gene, a X-linked gene involved in the activation of ubiquitin system. Patients present a broad spectrum of inflammatory manifestations (fever, neutrophilic dermatosis, chondritis, pulmonary infiltrates, ocular inflammation, venous thrombosis) and hematological involvement (macrocytic anemia, thrombocytopenia, vacuoles in myeloid and erythroid precursor cells, dysplastic bone marrow) that are responsible for a significant morbidity and mortality. The therapeutic management is currently poorly codified but is based on two main approaches: controlling inflammatory symptoms (by using corticosteroids, JAK inhibitor or tocilizumab) or targeting the UBA1-mutated hematopoietic population (by using azacitidine or allogeneic hematopoietic stem cell transplantation). Supportive care is also important and includes red blood cell or platelet transfusions, erythropoiesis stimulating agents, thromboprophylaxis and anti-infectious prophylaxis. The aim of this review is to provide a current overview of the VEXAS syndrome, particularly focusing on its pathophysiological, diagnostic and therapeutic aspects.

Clinical characteristics, disease trajectories and management of vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic (VEXAS) syndrome: a systematic review

BACKGROUND

VEXAS (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic) syndrome is a newly discovered autoinflammatory condition characterised by somatic mutation of the UBA1 gene. The syndrome leads to multi-system inflammation affecting predominantly the skin, lungs and bone marrow.

METHODS

We undertook a systematic review of the multisystem features and genotypes observed in VEXAS syndrome. Articles discussing VEXAS syndrome were included. Medline, Embase and Cochrane databases were searched. Information was extracted on: demographics, type and prevalence of clinical manifestations, genetic mutations and treatment. Meta-analysis using a random effects model was used to determine pooled estimates of serum markers.

RESULTS

From 303 articles, 90 were included, comprising 394 patients with VEXAS. 99.2% were male, with a mean age of 67.1 years (SD 8.5) at disease onset. The most frequent diagnoses made prior to VEXAS were: relapsing polychondritis (n = 59); Sweet's syndrome (n = 24); polyarteritis nodosa (n = 11); and myelodysplastic syndrome (n = 10). Fever was reported in 270 cases (68.5%) and weight loss in 79 (20.1%). Most patients had haematological (n = 342; 86.8%), dermatological (n = 321; 81.5%), pulmonary (n = 297; 75.4%%) and musculoskeletal (n = 172; 43.7%) involvement, although other organ manifestations of varying prevalence were also recorded. The most commonly reported mutations were "c.122T > C pMET41Thr" (n = 124), "c.121A > G pMET41Val" (n = 62) and "c.121A > C pMet41Leu" (n = 52). Most patients received glucocorticoids (n = 240; 60.9%) followed by methotrexate (n = 82; 20.8%) and IL-6 inhibitors (n = 61, 15.4%). One patient underwent splenectomy; 24 received bone marrow transplants.

CONCLUSION

VEXAS syndrome is a rare disorder affecting predominantly middle-aged men. This is the first systematic review to capture clinical manifestations, genetics and treatment of reported cases. Further studies are needed to optimise treatment and subsequently reduce morbidity and mortality.

Recurrent orbital inflammation associated with VEXAS syndrome

VEXAS (Vacuoles, E1 enzyme, X-linked, Autoinflammatory, Somatic) syndrome is a newly recognised adult-onset multisystem autoinflammatory disease caused by a somatic mutation in the UBA1 gene in myeloid or erythroid precursor cells. This report describes an atypical presentation of recurrent dacryoadenitis associated with VEXAS syndrome and provides a review of the literature. A 68-year-old male presented with three episodes of unilateral alternating dacryoadenitis followed by bilateral involvement over a 4-year period. Each episode of orbital inflammation was characterised by upper lid swelling, oedema and enlarged lacrimal glands. In addition, he experienced intermittent flares of angioedema-like lesions involving the face and extremities, recurrent jaw aches, rash, progressive pulmonary fibrosis, and myelodysplastic syndrome. His inflammatory symptoms lessened with prednisolone but were refractory to methotrexate. Mycophenolate was subsequently trialled with a reasonable clinical response. Genetic testing established the diagnosis of VEXAS syndrome and tofacitinib, a JAK inhibitor, was commenced with resolution of inflammatory symptoms.

[Tracheobronchial involvement in relapsing polychondritis and differential diagnoses]

Relapsing polychondritis is a systemic auto-immune disease that mainly affects cartilage structures, progressing through inflammatory flare-ups between phases of remission and ultimately leading to deformation of the cartilages involved. In addition to characteristic damage of auricular or nasal cartilage, tracheobronchial and cardiac involvement are particularly severe, and can seriously alter the prognosis. Tracheobronchial lesions are assessed by means of a multimodal approach, including dynamic thoracic imaging, measurement of pulmonary function (with recent emphasis on pulse oscillometry), and mapping of tracheal lesions through flexible bronchoscopy. Diagnosis can be difficult in the absence of specific diagnostic tools, especially as there may exist a large number of differential diagnoses, particularly as regards inflammatory diseases. The prognosis has improved, due largely to upgraded interventional bronchoscopy techniques and the development of immunosuppressant drugs and targeted therapies, offering patients a number of treatment options.

Relapsing polychondritis: clinical updates and new differential diagnoses

Relapsing polychondritis is a rare inflammatory disease characterized by recurrent inflammation of cartilaginous structures, mainly of the ears, nose and respiratory tract, with a broad spectrum of accompanying systemic features. Despite its rarity, prompt recognition and accurate diagnosis of relapsing polychondritis is crucial for appropriate management and optimal outcomes. Our understanding of relapsing polychondritis has changed markedly in the past couple of years with the identification of three distinct patient clusters that have different clinical manifestations and prognostic outcomes. With the progress of pangenomic sequencing and the discovery of new somatic and monogenic autoinflammatory diseases, new differential diagnoses have emerged, notably the vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic (VEXAS) syndrome, autoinflammatory diseases and immune checkpoint inhibitor-related adverse events. In this Review, we present a detailed update of the newly identified clusters and highlight red flags that should raise suspicion of these alternative diagnoses. The identification of these different clusters and mimickers has a direct impact on the management, follow-up and prognosis of patients with relapsing polychondritis and autoinflammatory syndromes.

[The most frequent febrile syndromes and autoinflammatory diseases in adulthood]

Autoinflammatory diseases are characterized by inflammatory manifestations in various organ systems, whereby recurrent febrile episodes, musculoskeletal complaints, gastrointestinal and cutaneous symptoms frequently occur accompanied by serological signs of inflammation. Autoinflammatory diseases include rare monogenic entities and multifactorial or polygenic diseases, which can manifest as a variety of symptoms in the course of time. Examples of monogenic autoinflammatory diseases are familial Mediterranean fever (FMF), cryopyrin-associated periodic syndrome (CAPS), tumor necrosis factor (TNF) receptor-associated periodic syndrome (TRAPS) and the recently described VEXAS (vacuoles, E1 enzyme, X‑linked, autoinflammatory and somatic) syndrome. For non-monogenically determined autoinflammatory diseases, the most important representatives in adulthood are adult-onset Still's disease (AOSD) and the Schnitzler syndrome, in which a polygenic susceptibility and epigenetic factors are more likely to play a role.

VEXAS syndrome

VEXAS syndrome is a recently identified, adult-onset autoinflammatory disease caused by somatic mutations in UBA1. UBA1 is an X-linked gene encoding E1 ubiquitin activating enzyme and its mutation in hematopoietic stem and progenitor cells leads to their clonal expansion and myeloid-skewed differentiation. UBA1 mutations in VEXAS are clustered at the second methionine (p.Met41), eliminating UBA1b isoform translated from p.Met41. Loss of UBA1b impairs ubiquitination and activates innate immune pathways, leading to systemic autoinflammation manifested as recurrent fever, chondritis, pulmonary involvement, vasculitis, or neutrophilic dermatitis. VEXAS syndrome is frequently associated with hematological disorders such as myelodysplastic syndrome (MDS), plasma cell dyscrasia and venous thromboembolism. Macrocytic anemia/macrocytosis and vacuoles in myeloid/erythroid precursors are prominent features of VEXAS syndrome, and their presence in patients with autoinflammatory symptoms prompts physicians to screen for UBA1 variant. Treatment of VEXAS syndrome is challenging and no consistently effective therapies have been established. Anti-inflammation therapies including glucocorticoids and anti-interleukin-6 have shown limited efficacy, while azacytidine and JAK inhibitors such as ruxolitinib were found to induce favorable, mid-term responses. Hematopoietic stem cell transplantation is the only curative option for VEXAS and should be considered for younger, fit patients with poor prognostic factors or recalcitrant symptoms.

Shared and distinct mechanisms of UBA1 inactivation across different diseases

Most cellular ubiquitin signaling is initiated by UBA1, which activates and transfers ubiquitin to tens of E2 enzymes. Clonally acquired UBA1 missense mutations cause an inflammatory-hematologic overlap disease called VEXAS (vacuoles, E1, X-linked, autoinflammatory, somatic) syndrome. Despite extensive clinical investigation into this lethal disease, little is known about the underlying molecular mechanisms. Here, by dissecting VEXAS-causing UBA1 mutations, we discovered that p.Met41 mutations alter cytoplasmic isoform expression, whereas other mutations reduce catalytic activity of nuclear and cytoplasmic isoforms by diverse mechanisms, including aberrant oxyester formation. Strikingly, non-p.Met41 mutations most prominently affect transthioesterification, revealing ubiquitin transfer to cytoplasmic E2 enzymes as a shared property of pathogenesis amongst different VEXAS syndrome genotypes. A similar E2 charging bottleneck exists in some lung cancer-associated UBA1 mutations, but not in spinal muscular atrophy-causing UBA1 mutations, which instead, render UBA1 thermolabile. Collectively, our results highlight the precision of conformational changes required for faithful ubiquitin transfer, define distinct and shared mechanisms of UBA1 inactivation in diverse diseases, and suggest that specific E1-E2 modules control different aspects of tissue differentiation and maintenance.

Unveiling the clinical spectrum of relapsing polychondritis: insights into its pathogenesis, novel monogenic causes, and therapeutic strategies

Relapsing polychondritis is a rare multisystem disease involving cartilaginous and proteoglycan-rich structures. The diagnosis of this disease is mainly suggested by the presence of flares of inflammation of the cartilage, particularly in the ears, nose or respiratory tract, and more rarely, in the presence of other manifestations. The spectrum of clinical presentations may vary from intermittent episodes of painful and often disfiguring auricular and nasal chondritis to an occasional organ or even life-threatening manifestations such as lower airway collapse. There is a lack of awareness about this disease is mainly due to its rarity. In 2020, VEXAS (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic) syndrome, a novel autoinflammatory syndrome, was described. VEXAS syndrome is attributed to somatic mutations in methionine-41 of UBA1, the major E1 enzyme that initiates ubiquitylation. This new disease entity connects seemingly unrelated conditions: systemic inflammatory syndromes (relapsing chondritis, Sweet's syndrome, and neutrophilic dermatosis) and hematologic disorders (myelodysplastic syndrome or multiple myeloma). Therefore, this article reviews the current literature on both disease entities.

[Macrocytic anemia and polychondritis: VEXAS syndrome]

An adult-onset autoinflammatory syndrome caused by somatic mutations in the UBA1 gene on the X chromosome was first reported in 2020. This VEXAS syndrome (acronym for vacuoles, E1 enzyme, X‑linked, autoinflammatory, somatic) is characterized by an overlap of rheumatic inflammatory diseases with separate hematologic abnormalities. A substantial number of affected patients suffer from treatment refractory relapsing polychondritis and nearly always show signs of macrocytic anemia. This case report illustrates the diagnostic key points to recognizing patients with VEXAS syndrome.

VEXAS syndrome: A review of cutaneous findings and treatments in an emerging autoinflammatory disease

VEXAS (vacuoles, E1 enzyme, X-linked, autoinflammatory and somatic mutation) syndrome is a novel autoinflammatory, late-onset, disorder first identified in 2020. It is caused by mutations in the UBA1 gene. The most prominent clinical features reported by VEXAS patients are cutaneous and haematological, having characteristic skin features reported as the initial presenting findings of the disease. VEXAS is a severe and treatment-resistant condition with high morbidity and mortality rates. Here, we examine all case reports and case series of VEXAS syndrome through March 2023 focusing on those presenting cutaneous manifestations. We discuss these manifestations and their reported treatment strategies. In many cases, it might be first suspected and diagnosed by dermatologists, highlighting their vital role in initiating timely multidisciplinary care.

Functional genomics in inborn errors of immunity

Inborn errors of immunity (IEI) comprise a diverse spectrum of 485 disorders as recognized by the International Union of Immunological Societies Committee on Inborn Error of Immunity in 2022. While IEI are monogenic by definition, they illuminate various pathways involved in the pathogenesis of polygenic immune dysregulation as in autoimmune or autoinflammatory syndromes, or in more common infectious diseases that may not have a significant genetic basis. Rapid improvement in genomic technologies has been the main driver of the accelerated rate of discovery of IEI and has led to the development of innovative treatment strategies. In this review, we will explore various facets of IEI, delving into the distinctions between PIDD and PIRD. We will examine how Mendelian inheritance patterns contribute to these disorders and discuss advancements in functional genomics that aid in characterizing new IEI. Additionally, we will explore how emerging genomic tools help to characterize new IEI as well as how they are paving the way for innovative treatment approaches for managing and potentially curing these complex immune conditions.

Autoimmunity and Autoinflammation: Relapsing Polychondritis and VEXAS Syndrome Challenge

Relapsing polychondritis is a chronic autoimmune inflammatory condition characterized by recurrent episodes of inflammation at the level of cartilaginous structures and tissues rich in proteoglycans. The pathogenesis of the disease is complex and still incompletely elucidated. The data support the important role of a particular genetic predisposition, with HLA-DR4 being considered an allele that confers a major risk of disease occurrence. Environmental factors, mechanical, chemical or infectious, act as triggers in the development of clinical manifestations, causing the degradation of proteins and the release of cryptic cartilage antigens. Both humoral and cellular immunity play essential roles in the occurrence and perpetuation of autoimmunity and inflammation. Autoantibodies anti-type II, IX and XI collagens, anti-matrilin-1 and anti-COMPs (cartilage oligomeric matrix proteins) have been highlighted in increased titers, being correlated with disease activity and considered prognostic factors. Innate immunity cells, neutrophils, monocytes, macrophages, natural killer lymphocytes and eosinophils have been found in the perichondrium and cartilage, together with activated antigen-presenting cells, C3 deposits and immunoglobulins. Also, T cells play a decisive role in the pathogenesis of the disease, with relapsing polychondritis being considered a TH1-mediated condition. Thus, increased secretions of interferon γ, interleukin (IL)-12 and IL-2 have been highlighted. The "inflammatory storm" formed by a complex network of pro-inflammatory cytokines and chemokines actively modulates the recruitment and infiltration of various cells, with cartilage being a source of antigens. Along with RP, VEXAS syndrome, another systemic autoimmune disease with genetic determinism, has an etiopathogenesis that is still incompletely known, and it involves the activation of the innate immune system through different pathways and the appearance of the cytokine storm. The clinical manifestations of VEXAS syndrome include an inflammatory phenotype often similar to that of RP, which raises diagnostic problems. The management of RP and VEXAS syndrome includes common immunosuppressive therapies whose main goal is to control systemic inflammatory manifestations. The objective of this paper is to detail the main etiopathogenetic mechanisms of a rare disease, summarizing the latest data and presenting the distinct features of these mechanisms.

VEXAS and Myelodysplastic Syndrome: An Interdisciplinary Challenge

VEXAS (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic) syndrome is a recently recognized systemic autoinflammatory disease caused by somatic mutations in hematopoietic progenitor cells. This case series of four patients with VEXAS syndrome and comorbid myelodysplastic syndrome (MDS) aims to describe clinical, imaging, and hematologic disease presentations as well as response to therapy. Four patients with VEXAS syndrome and MDS are described. A detailed analysis of imaging features, hemato-oncological presentation including bone marrow microscopy and clinical-rheumatological disease features and treatment outcomes is given. All patients were male; ages ranged between 64 and 81 years; all were diagnosed with MDS. CT imaging was available for three patients, all of whom exhibited pulmonary infiltrates of varying severity, resembling COVID-19 or hypersensitivity pneumonitis without traces of scarring. Bone marrow microscopy showed maturation-disordered erythropoiesis and pathognomonic vacuolation. Somatic mutation in the UBA1 codon 41 were found in all patients by next-generation sequencing. Therapy regimes included glucocorticoids, JAK1/2-inhibitors, nucleoside analogues, as well as IL-1 and IL-6 receptor antagonists. No fatalities occurred (observation period from symptom onset: 18-68 months). Given the potential underreporting of VEXAS syndrome, we highly recommend contemporary screening for UBA1 mutations in patients presenting with ambiguous signs of systemic autoinflammatory symptoms which persist over 18 months despite treatment. The emergence of cytopenia, especially macrocytic hyperchromic anemia, should prompt early testing for UBA1 mutations. Notably conspicuous, pulmonary alterations in CT imaging of patients with therapy-resistant systemic autoinflammatory symptoms should be discussed in interdisciplinary medical teams (Rheumatology, Hematology, Radiology and further specialist departments) to facilitate timely diagnosis during the clinical course of the disease.

Clonal hematopoiesis and autoimmunity

Clonal hematopoiesis (CH) has been associated with aging, occurring in about 10% of individuals aged >70 years, and immune dysfunction. Aged hematopoietic stem and progenitor cells exhibit pathological changes in immune function and activation of inflammatory pathways. CH clones commonly harbor a loss of function mutation in DNMT3A or TET2, which causes increased expression of inflammatory signaling genes, a proposed mechanism connected to CH and the development of age-related diseases. Additionally, inflammation may stress the hematopoietic compartment, driving the expansion of mutant clones. While the epidemiologic overlap between CH, hematologic malignancies, and atherosclerotic cardiovascular diseases has been reported, the mechanisms linking these concepts are largely unknown and merit much further investigation. Here, we review studies highlighting the interplay between CH, inflamm-aging, the immune system, and the prevalence of CH in autoimmune diseases.

Cutaneous vasculitis in autoinflammatory diseases

Autoinflammatory diseases (AIDs) characterized by recurrent episodes of localized or systemic inflammation are disorders of the innate immune system. Skin lesions are commonly found in AIDs and cutaneous vasculitis can coexist with AIDs and even present as the most striking feature. This review aims to focus on the frequent cutaneous vasculitis association in three monogenic AIDs including familial Mediterranean fever (FMF), deficiency of adenosine deaminase type 2 (DADA2), and the recently identified adult-onset VEXAS (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic) syndrome. Cutaneous vasculitis in FMF is characterized by: (1) small-vessel vasculitis similar to IgA vasculitis with palpable purpura but increased intussusception complication and less vascular IgA deposit, and (2) cutaneous arteritis-like vasculitis presenting as subcutaneous nodules most often with higher glomerular involvement. DADA2 has a wide spectrum of clinical presentations ranging from fatal systemic vasculitis with multiple strokes, especially in pediatric patients, to limited cutaneous disease in middle-aged patients. DADA2 shares similar clinical and histopathological features with polyarteritis nodosa (PAN). As a result, DADA2 is commonly initially misdiagnosed as childhood PAN. Livedo racemosa reveals the most common cutaneous manifestation of cutaneous vasculitis in patients with DADA2. VEXAS syndrome is a life-threatening disease. A diagnosis of VEXAS syndrome should be strongly considered or could be made in patients with skin lesions characterized by Sweet syndrome-like eruption, livedo racemosa, concomitant relapsing polychondritis, deep venous thrombosis, pulmonary involvement, and progressive hematologic abnormalities such as myelodysplastic syndrome with a unique finding of cytoplasmic vacuoles in myeloid and erythroid precursor cells from bone marrow aspirate smear. As skin involvement is common in AIDs and may present as the most frequent manifestation, especially in DADA2 (70% to 90%) and VEXAS syndrome (83% to 91%), dermatologists play a crucial role in contributing to the early diagnosis of these AIDs with early initiation of the appropriate therapy to avoid progressing fatal outcomes.

Vacuoles in bone marrow progenitors: VEXAS syndrome and beyond

The presence of vacuoles in myeloid and erythroid progenitor cells in bone marrow aspirates is a key feature of vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic (VEXAS) syndrome. The mere observation of vacuolated progenitor cells is not specific to VEXAS syndrome; in this Viewpoint, we point out the causes to be considered in this situation. Vacuoles, in particular, can be observed in individuals with wild-type UBA1 and with persistent inflammatory features or myelodysplastic syndromes. However, several clues support the diagnosis of VEXAS syndrome in the presence of vacuolated bone marrow progenitors: a high number of vacuolated progenitors and of vacuoles per cell, the predominance of vacuoles in early rather than late progenitors, and the vacuolisation of both myeloid and erythroid progenitors with predominance of myeloid ones. Some criteria derived from these observations have been proposed with great diagnostic performances. However, the absence or a low proportion of vacuolated cells should not prevent UBA1 gene sequencing.

VEXAS syndrome: Clinical, hematologic features and a practical approach to diagnosis and management

VEXAS (Vacuoles, E1 enzyme, X-linked, Autoinflammatory, Somatic) syndrome is a newly identified disease caused by somatic alterations in UBA1 which produce a recalcitrant inflammatory state along with hematologic disturbances. Patients with VEXAS can have a wide spectrum of clinical symptoms and providers should be familiar with the heterogeneity of associated clinical features. While hematologic parameters may be generally non-specific, peripheral blood features of macrocytosis, monocytopenia, and/or thrombocytopenia coupled with bone marrow vacuolization of erythroid or myeloid precursors should raise suspicion for this condition. Due to an increased mortality, prompt recognition and accurate diagnosis is paramount. Access to testing for confirmation of UBA1 variants is not yet universally available but clinicians should understand the current available options for genetic confirmation of this disease. Treatment options are limited due to lack of prospective clinical trials but cytokine directed therapies such as interleukin-6 inhibitors and JAK-STAT inhibitors as well as hypomethylating agents such as azacitidine have shown evidence of partial effect. Though cases are limited, allogeneic stem cell transplantation holds promise for durable response and potential cure. The intent of this review is to outline the pathophysiology of VEXAS syndrome and to provide a practical approach to diagnosis and treatment.

VEXAS syndrome is characterized by inflammasome activation and monocyte dysregulation

Acquired mutations in the UBA1 gene were recently identified in patients with severe adult-onset auto-inflammatory syndrome called VEXAS (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic). However, the precise physiological and clinical impact of these mutations remains poorly defined. Here we study a unique prospective cohort of VEXAS patients. We show that monocytes from VEXAS are quantitatively and qualitatively impaired and display features of exhaustion with aberrant expression of chemokine receptors. In peripheral blood from VEXAS patients, we identify an increase in circulating levels of many proinflammatory cytokines, including IL-1β and IL-18 which reflect inflammasome activation and markers of myeloid cells dysregulation. Gene expression analysis of whole blood confirms these findings and also reveals a significant enrichment of TNF-α and NFκB signaling pathways that can mediate cell death and inflammation. This study suggests that the control of the nflammasome activation and inflammatory cell death could be therapeutic targets in VEXAS syndrome.

Case report: VEXAS as an example of autoinflammatory syndrome in pulmonology clinical practice

Lung involvement is not widely recognized as a complication of auto-inflammatory diseases. We present a broad approach to diagnose a severe form of autoinflammatory syndrome in an adult male patient. A 63-year-old Caucasian male presented with recurrent episodes of high fever, interstitial lung infiltration, and pleural effusion. Laboratory tests performed during the flares revealed lymphopenia and increased levels of C-reactive protein and ferritin. Broad diagnostic research on infections, connective tissue diseases, and malignancies yielded negative results. The patient's symptoms promptly resolved upon the administration of glucocorticoids; however, they reappeared when the prednisone dose was reduced. All attempts to administer immunomodulatory and immunosuppressive medications were ineffective. During follow-up, autoinflammatory syndrome was suspected; however, no pathological variants of monogenic autoinflammatory diseases were identified by genome-exome sequencing. The patient did not respond to interleukin 1 blockade with anakinra. He died due to multi-organ failure, and his condition remained unresolved until the first reported description of vacuole, E1 enzyme, X-linked, autoinflammatory, and somatic syndrome (VEXAS). We describe the diagnostic traps and reasoning process involved in establishing that the patient's symptoms were autoinflammatory in nature based on clinical symptoms, in addition to the proof of concept gained from genetic reevaluation and identification of pathogenic variants in the UBA1 gene. The aim of this review is to increase the awareness of VEXAS among pulmonologists. Genetic screening for UBA1 should be considered in patients with recurrent pneumonitis of unknown origin with elevated inflammatory markers and signs of cytopenia, especially if they require chronic steroids to control the disease. Respiratory manifestations are part of VEXAS; these may be dominant in the course of the disease and severe at presentation.

Clonal Hematopoiesis, Inflammation, and Hematologic Malignancy

Somatic or acquired mutations are postzygotic genetic variations that can occur within any tissue. These mutations accumulate during aging and have classically been linked to malignant processes. Tremendous advancements over the past years have led to a deeper understanding of the role of somatic mutations in benign and malignant age-related diseases. Here, we review the somatic mutations that accumulate in the blood and their connection to disease states, with a particular focus on inflammatory diseases and myelodysplastic syndrome. We include a definition of clonal hematopoiesis (CH) and an overview of the origins and implications of these mutations. In addition, we emphasize somatic disorders with overlapping inflammation and hematologic disease beyond CH, including paroxysmal nocturnal hemoglobinuria and aplastic anemia, focusing on VEXAS (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic) syndrome. Finally, we provide a practical view of the implications of somatic mutations in clinical hematology, pathology, and beyond.

Vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic (VEXAS) syndrome presenting as recurrent aseptic peritonitis in a patient receiving peritoneal dialysis: a case report

BACKGROUND

Vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic (VEXAS) syndrome is caused by mutations in the ubiquitin-activating enzyme1 (UBA1) gene and characterised by an overlap between autoinflammatory and haematologic disorders.

CASE PRESENTATION

We reported a case of a 67-year-Japanese man receiving peritoneal dialysis (PD) who had recurrent aseptic peritonitis caused by the VEXAS syndrome. He presented with unexplained fevers, headache, abdominal pain, conjunctival hyperaemia, ocular pain, auricular pain, arthralgia, and inflammatory skin lesions. Laboratory investigations showed high serum C-reactive protein concentration and increased cell count in PD effluent. He was treated with antibiotics for PD-related peritonitis, but this was unsuccessful. Fluorine-18-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography images demonstrated intense FDG uptake in his left superficial temporal artery, nasal septum, and bilateral auricles. The working diagnosis was giant cell arteritis, and he was treated with oral prednisolone (PSL) 15 mg daily with good response. However, he was unable to taper the dose to less than 10 mg daily because his symptoms flared up. Since Tocilizumab was initiated, he could taper PSL dose to 2 mg daily. Sanger sequencing of his peripheral blood sample showed a mutation of the UBA1 gene (c.122 T > C; p.Met41Thr). We made a final diagnosis of VEXAS syndrome. He suffered from flare of VEXAS syndrome at PSL of 1 mg daily with his cloudy PD effluent. PSL dose of 11 mg daily relieved the symptom within a few days.

CONCLUSIONS

It is crucial to recognise aseptic peritonitis as one of the symptoms of VEXAS syndrome and pay attention to the systemic findings in the patients.

Dynamic monitoring of UBA1 somatic mutations in patients with relapsing polychondritis

BACKGROUND

Commonly clinically diagnosed with relapsing polychondritis (RP), vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic syndrome (VEXAS) is a recently identified autoinflammatory disease caused by UBA1 somatic mutations. The low frequency and dynamic changes challenge the accurate detection of somatic mutations. The present study monitored these mutations in Chinese patients with RP. We included 44 patients with RP. Sanger sequencing of UBA1 was performed using genomic DNA from peripheral blood. Droplet digital polymerase chain reaction (ddPCR) was performed to screen low-prevalence somatic variants.

RESULTS

Multiple ddPCR detections were performed using available blood samples collected at different follow-up time points. Three male patients were UBA1 somatic mutation carriers. Sanger sequencing detected the somatic UBA1 variant c.122T > C (p.Met41Thr) in two male patients. Initial ddPCR confirmed the variant in the two patients, with allele fractions of 73.75% and 88.46%, respectively, while yielding negative results in other patients. Subsequent ddPCR detected the somatic variant (c.122T > C) with low prevalence (1.02%) in another male patient from blood samples collected at a different time point, and confirmed dynamically fractional abundance in one patient with VEXAS, with allele fractions of 73.75%, 61.28%, 65.01%, and 73.75%. Nine patients assessed by ddPCR at different time points remained negative.

CONCLUSION

We report UBA1 variants in patients with RP in the Chinese population for the first time. Multiple ddPCR detections from samples collected at different time points can enhance sensitivity and should be considered for patients with initial negative ddPCR results.

VEXAS Syndrome-Diagnostic Clues for the Dermatologist and Gaps in Our Current Understanding: A Narrative Review

Vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic syndrome is a newly recognized, acquired autoinflammatory disorder with broad systemic implications and a poor global prognosis. Because cutaneous lesions are present in the majority of those affected, it is necessary that dermatologists are equipped to recognize this important disease. Through identification, there is a greater opportunity for disease stratification, surveillance for systemic involvement, and selection of the best available therapies. As our understanding of this disease develops, dermatologists should also play a role in addressing the knowledge gaps that exist.

VEXAS syndrome: Clinical manifestations, diagnosis, and treatment

VEXAS (Vacuoles, E1 enzyme, X-linked, Autoinflammatory, Somatic) syndrome is an adult-onset autoinflammatory syndrome characterized by somatic mutations in the UBA1 gene and is considered the prototype of hematoinflammatory diseases. Patients with VEXAS syndrome exhibit inflammatory and hematological manifestations that can lead to clinical diagnoses such as relapsing polychondritis, polyarteritis nodosa, Sweet syndrome, and myelodysplastic syndrome. Diagnosis requires bone marrow evaluation to identify cytoplasmic vacuoles in myeloid and erythroid precursors. However, genetic confirmation of mutations in UBA1 is necessary. Treatment is challenging and often involves glucocorticoids and immunosuppressants with variable responses. Hypomethylating agents and allogenic haemopoietic stem cell transplant are considered promising therapies. Prognosis is influenced by genetic and clinical factors. The aim of this review is to provide an overview of the pathogenesis, clinical presentation, treatment, and prognosis of VEXAS syndrome for the Latin American medical community.

Clinical Manifestations in Vacuoles, E1 Enzyme, X-Linked, Autoinflammatory, Somatic (VEXAS) Syndrome: A Narrative Review

The newly identified refractory adult-onset autoinflammatory syndrome known as VEXAS (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic) syndrome is brought on by somatic mutations in the ubiquitin-like modifier-activating enzyme 1 (UBA1) gene in hematopoietic stem and progenitor cells that change the expression of the UBA1 isoform. As a result, patients have a variety of hematologic and systemic inflammatory symptoms. All types of medical professionals should treat VEXAS syndrome seriously due to the high fatality rate. To better comprehend the condition and enhance the prognosis for VEXAS syndrome, this review article describes the essential traits and clinical signs of the condition. The discussion of future directions in the study of systemic inflammatory disorders brought on by somatic mutations concludes.

CircGPRC5A enhances colorectal cancer progress by stabilizing PPP1CA and inducing YAP dephosphorylation

BACKGROUND

With the advancements in bioinformatic technology, an increasing number of circular RNAs (circRNAs) have been discovered and their crucial roles in the development and progression of various malignancies have been confirmed through multiple pathways. However, the specific mechanisms involving protein-binding circRNAs in colorectal cancer (CRC) remain largely unexplored.

METHODS

Differential circRNA expression was assessed using a human circRNA microarray in five CRC tissue and paired normal samples. CircGPRC5A expression was then confirmed in the CRC tissues and paired normal samples using qRT-PCR. The biological function of circGPRC5A in CRC were studied in vitro and in vivo. Western blotting, fluorescence in situ hybridization, immunofluorescence, RNA pulldown, mass spectrometry, immunoprecipitation, quantitative phosphoproteomics, and RNA-binding protein immunoprecipitation assays were used to study circGPRC5A.

RESULTS

Our analysis revealed that circGPRC5A expression was higher in CRC tissues compared to normal tissues and was associated with tumor size, tumor stage and lymph node status. CircGPRC5A promoted CRC cell proliferation, migration, and metastasis in vitro and in vivo. CircGPRC5A could stabilize PPP1CA protein by inhibiting the binding between UBA1 and PPP1CA, and increasing YAP dephosphorylation.

CONCLUSIONS

Our study revealed that circGPRC5A plays an essential function in CRC progression by stabilizing PPP1CA protein and enhancing YAP dephosphorylation. CircGPRC5A could act as a novel and potential target for CRC.

VEXAS-Syndrome, a newly described autoinflammatory systemic disease with dermatologic manifestations

VEXAS syndrome is a recently identified autoinflammatory systemic disease caused by an acquired somatic mutation of the X-linked UBA1 gene, the key enzyme of the first step of ubiquitylation. The acronym VEXAS stands for the characteristics Vacuoles, E1 enzyme, X-linked, autoinflammatory and somatic. The disease occurs in advanced adulthood preferentially in men and is characterized by hematological, rheumatological and dermatological symptoms. The latter include neutrophil-rich lesions reminiscent of Sweet's syndrome, erythema nodosum- and panniculitis-like skin manifestations and recurrent polychondritis of the nose and auricles. The presence of cytoplasmic vacuoles in myeloid and erythroid precursors in the bone marrow is characteristic. In up to half of the cases, VEXAS syndrome is associated with myelodysplastic syndrome. Dermatologists should be familiar with the clinical picture, as skin symptoms are often the first indicator of the disease. Molecular diagnostics are essential for confirming the diagnosis and risk stratification of affected patients. In this minireview we provide an overview of the pathophysiology, diagnosis and therapy of VEXAS syndrome and illustrate its clinical picture with two own cases.

Targeted testing of bone marrow specimens with cytoplasmic vacuolization to identify previously undiagnosed cases of VEXAS syndrome

OBJECTIVE

To retrospectively identify patients with VEXAS syndrome (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic syndrome) among male patients with bone marrow vacuolization using a clinically applicable, targeted-screening approach.

METHODS

Bone marrow reports from 1 May 2014 through 18 February 2022 were reviewed for documentation of cytoplasmic vacuolization. Patients with acute leukaemia, lymphoma, metastatic solid tumour, amyloidosis or POEMS (polyneuropathy, organomegaly, endocrinopathy, monoclonal protein, skin changes) syndrome were excluded, as were those without clinical records available for direct chart review. Cases were rated for suspicion of VEXAS syndrome using a 5-point scale based on the presence of laboratory findings, clinical features and treatment response. Patients with available DNA material and moderate (three patients) or high (four to five patients) suspicion were tested for somatic UBA1 variants associated with VEXAS syndrome.

RESULTS

A total of 315 reports from 292 unique patients included documentation of vacuolization. Following exclusion criteria, 64 patients underwent direct medical chart review to assess likelihood of VEXAS syndrome, for which 21 patients met moderate to high suspicion. Available DNA was present in eight patients, seven (87.5%) of whom had a pathogenic somatic UBA1 variant consistent with VEXAS syndrome. The distribution of cytoplasmic vacuolization in the bone marrow biopsy reports among patients with VEXAS syndrome were erythroid and myeloid precursors (6/7), erythroid precursors only (1/7) and myeloid precursors only (0/7).

CONCLUSION

In this study, the utilization of a clinically applicable targeted-screening approach to test bone marrow specimens (with vacuolization) for the presence of previously undiagnosed VEXAS syndrome resulted in a positive detection rate of 87.5%.

VEXAS-Syndrom, eine neu beschriebene autoinflammatorische Systemerkrankung mit dermatologischen Manifestationen

Das VEXAS‐Syndrom ist eine kürzlich erstbeschriebene autoinflammatorische Systemerkrankung, die auf einer erworbenen, somatischen Mutation des X‐chromosomal lokalisierten UBA1‐Gens, dem Schlüsselenzym des ersten Schritts der Ubiquitinierung, beruht. Das Akronym VEXAS steht für die Charakteristika Vacuoles, E1 enzyme, X‐linked, autoinflammatory und somatic. Die Erkrankung tritt im fortgeschrittenen Erwachsenenalter vorzugsweise bei Männern auf und ist insbesondere durch hämatologische, rheumatologische und dermatologische Symptome gekennzeichnet. Letztere umfassen unter anderem neutrophilenreiche, an das Sweet‐Syndrom erinnernde Läsionen, Erythema nodosum‐ und Pannikulitis‐artige Hauterscheinungen sowie rezidivierende Polychondritiden an Nase und Ohrmuscheln. Das Vorliegen zytoplasmatischer Vakuolen in myeloiden und erythroiden Vorläuferzellen des Knochenmarks ist charakteristisch. In bis zur Hälfte der Fälle ist das VEXAS‐Syndrom mit einem myelodysplastischen Syndrom vergesellschaftet. Dermatologen sollten das Krankheitsbild kennen, da Hauterscheinungen oft der erste Indikator für die Erkrankung sind. Eine molekulare Diagnostik ist essenziell für die Diagnosesicherung und die Risikostratifizierung betroffener Patienten. In dieser Arbeit geben wir einen Überblick über die Pathophysiologie, Diagnostik und Therapie des VEXAS‐Syndroms und illustrieren das klinische Spektrum anhand zweier eigener Fälle.

VEXAS syndrome (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic) for the dermatologist

In 2020, Beck et al1 described a novel adult autoinflammatory syndrome entitled VEXAS (Vacuoles, E1 enzyme, X-linked, Autoinflammatory, Somatic), a newly-discovered disorder that connected previously unrelated inflammatory syndromes and a prototype for a new class of hematoinflammatory diseases.2 Eighty-nine percent of published cases have documented skin involvement, but despite the high incidence and diagnostic accessibility of skin manifestations, there has been little focus on the dermatological features of VEXAS syndrome thus far. A PubMed search of all published case reports of VEXAS syndrome to date was performed, with inclusion of all cases confirmed by genetic sequencing, and this review summarizes the reported dermatological signs. There have already been 141 confirmed published cases since original publication, 126 of which had documented cutaneous signs.1-34 A wide range of skin presentations are reported, including Sweet-like urticated and tender erythematous nodules, cartilaginous involvement with chondritis, cutaneous vasculitis, and periorbital angiodema.1-34 Many patients had been diagnosed with Sweet syndrome, relapsing polychondritis, polyarteritis nodosa, or erythema nodosum.1-34 Hallmarks of skin histopathology are a neutrophilic dermatosis with coexisting or exclusive leukocytoclastic vasculitis.1 The new classification therefore helps link previously disparate inflammatory skin conditions into a unifying pathophysiological pathway.

Bibliometric analysis of the global publication activity in the field of relapsing polychondritis during 1960-2023

BACKGROUND

Relapsing polychondritis (RP) is an inflammatory disease with significant individual heterogeneity that involves systemic cartilage tissues. This study aimed to perform a bibliometric analysis of RP-related publications to quantitatively assess the scholarly productivity in the field.

METHODS

We extracted the RP-related original research articles and reviews published during 1960-2023 from the Web of Science database by using the keyword "relapsing polychondritis." By using R, CiteSpace, VOSviewer, and SCImago Graphica, the bibliometric analysis was performed on the retrieved publications.

RESULTS

A total of 1096 articles, consisting of 909 original research articles and 187 reviews, were identified. A mean annual growth rate of 6.71% was found in the number of RP-related publications during 1960-2022. The United States accounted for the highest number of publications (21.9%), exhibited the highest mean citation number per publication (40.7), and engaged in the most frequent academic collaboration. Three clusters of RP-related journals were identified: 1) otology, rhinology, and laryngology; 2) respiratory and radiology medicine; and 3) rheumatology. Journals with a focus on rheumatology issued the most publications, and most of the RP-related publications were from The Journal of Rheumatology (n = 27). Most of these publications were co-authored by Dr. Jean-Charles Piette (n = 19), who also had the highest H-index (13) among all the authors. The co-citation network analysis revealed 11 highly connected clusters of RP research and indicated the "VEXAS Syndrome" as a hotspot.

CONCLUSION

This overview of the RP research field comprehensively describes the progress in the field. The number of publications on RP has progressively increased but remains insufficient. The United States and European countries are at the forefront of RP-related research, and the journals related to rheumatology have covered the majority of publications. Additionally, several key topics for future investigations, such as "VEXAS Syndrome," have been identified. Key Points •We identified a mean annual growth rate of 6.71% in the number of the RP-related publications during 1960-2022. •The United States accounted for the majority of the publications, exhibited the highest mean citation number per publication, and engaged in the most frequent academic collaborations. •The journals of the publications were categorized into three clusters of research areas: 1) otology, rhinology, and laryngology; 2) respiratory and radiology medicine; and 3) rheumatology. Journals related to rheumatology issued the most publications, and most of the publications were from The Journal of Rheumatology •Most of the publications were co-authored by Dr. Jean-Charles Piette, who also had the highest scientific-research impact among the scholars in the field. •The co-citation network analysis revealed 11 highly connected clusters of RP research and indicated the "VEXAS Syndrome" as a key research area.

[Relapsing polychondritis]

Relapsing polychondritis (RP) is a rare multisystemic disease predominantly involving the extracellular matrix. Typical manifestations are chondritis of the ears, nose and trachea as well as an asymmetrical oligoarthritis or polyarthritis of small and also larger joints. Various other involvements have also been described. The treatment of RP is individually dependent on a variety of factors, e.g., organ manifestations. Glucocorticoids, immunosuppressants and targeted treatment are implemented. In the case of seronegative rheumatoid arthritis or vasculitis with an atypical course the symptoms of RP should be taken into consideration.

Relapsing Polychondritis in a Patient With Rheumatoid Arthritis: Improved With Pentoxifylline

Relapsing polychondritis (RP) is a rare autoimmune condition that involves the recurrent inflammation of cartilage throughout the body, with a predilection for auricular and nasal cartilage. Given its rarity and diverse clinical presentations, RP is frequently misdiagnosed or left untreated, which can lead to significant morbidity and mortality. When it is correctly diagnosed, there are no standardized guidelines on the treatment of RP to date. Management of this disease requires a multidisciplinary approach, and about 30% of patients with RP have other autoimmune disorders, further complicating the approach to targeted treatment. Biologic agents (including TNF inhibitors) are commonly used. We present a compelling case of a 46-year-old female with rheumatoid arthritis (well-controlled on adalimumab) and hypothyroidism who presented to the dermatology clinic with recurrent episodes of painful, swollen, and erythematous ears, leading to a clinical diagnosis of relapsing polychondritis. Off-label use of oral pentoxifylline, along with topical corticosteroids, led to significant improvement in her symptoms. Dermatologists play an important role in the diagnosis of this rare disorder, as skin manifestations may be the initial presenting sign of RP. Further research into potentially effective treatments is needed. Timely identification and management of RP may prevent the progression of cartilage destruction, thus improving patients' long-term prognosis and overall quality of life.

Shared and Distinct Mechanisms of UBA1 Inactivation Across Different Diseases

Most cellular ubiquitin signaling is initiated by UBA1, which activates and transfers ubiquitin to tens of E2 enzymes. Clonally acquired UBA1 missense mutations cause an inflammatory-hematologic overlap disease called VEXAS (vacuoles, E1, X-linked, autoinflammatory, somatic) syndrome. Despite extensive clinical investigation into this lethal disease, little is known about the underlying molecular mechanisms. Here, by dissecting VEXAS-causing UBA1 mutations, we discovered that p.Met41 mutations alter cytoplasmic isoform expression, whereas other mutations reduce catalytic activity of nuclear and cytoplasmic isoforms by diverse mechanisms, including aberrant oxyester formation. Strikingly, non-p.Met41 mutations most prominently affect transthioesterification, revealing ubiquitin transfer to cytoplasmic E2 enzymes as a shared property of pathogenesis amongst different VEXAS syndrome genotypes. A similar E2 charging bottleneck exists in some lung cancer-associated UBA1 mutations, but not in spinal muscular atrophy-causing UBA1 mutations, which instead, render UBA1 thermolabile. Collectively, our results highlight the precision of conformational changes required for faithful ubiquitin transfer, define distinct and shared mechanisms of UBA1 inactivation in diverse diseases, and suggest that specific E1-E2 modules control different aspects of tissue differentiation and maintenance.