Azacitidine for patients with Vacuoles, E1 Enzyme, X-linked, Autoinflammatory, Somatic syndrome (VEXAS) and myelodysplastic syndrome: data from the French VEXAS registry

Clonal hematopoiesis meets an autoinflammatory disease: the new paradigm of VEXAS syndrome

INTRODUCTION

VEXAS (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic) syndrome is an acquired autoinflammatory disorder caused by somatic mutations in the UBA1 gene. Predominantly affecting males over 50, the disease presents with systemic inflammation, hematologic abnormalities, and features of clonal hematopoiesis, with nearly half of patients developing myelodysplastic syndromes (MDS). The interaction between inflammation and clonal expansion defines disease progression, emphasizing the need for a comprehensive understanding of its pathogenesis and management.

AREAS COVERED

This review discusses the clinical spectrum, genetic landscape, and pathogenic mechanisms of VEXAS syndrome. The correlation between UBA1 mutations and disease severity is explored, alongside the role of clonal hematopoiesis and inflammatory pathways. Current treatments, including corticosteroids, immunosuppressants, JAK inhibitors, and azacitidine, are evaluated for efficacy and limitations. The potential of allogeneic hematopoietic stem cell transplantation (allo-HSCT) as a curative approach is also addressed. Literature search was conducted from January 2020 to present using PubMed and Scopus databases to identify relevant studies.

EXPERT OPINION

VEXAS syndrome reflects a complex interaction between autoinflammation and clonal hematopoiesis. While targeted therapies offer symptomatic control, responses remain variable. Future strategies should focus on genotype-driven, personalized treatments and optimizing allo-HSCT protocols to improve patient outcomes and offer disease-modifying potential.

Bilateral Alternate Orbital and Ocular Manifestations in a VEXAS Syndrome Patient

PURPOSE

VEXAS syndrome, caused by somatic UBA1 gene mutations, is a recently described autoinflammatory disorder characterized by systemic inflammation and hematologic abnormalities. Ocular involvement occurs in 28-40% of cases. This report describes a unique case of VEXAS syndrome with recurrent bilateral orbital and ocular inflammation, including the first documented concurrent ocular and orbital disease in the same patient, as well as of vitritis.

METHODS

A 79-year-old male presented with recurrent bilateral orbital and ocular inflammation, featuring periorbital oedema, dacryoadenitis, fibrinous anterior uveitis, vitritis, and macular oedema. He also developed fatigue, malaise, weight loss, dry cough, shortness of breath, joint and muscle pain, and chest pain and was followed for over one year.

RESULTS

Diagnostic work-up included multimodal ophthalmic imaging, CT orbits and serologic testing. The diagnosis was confirmed by genetic testing for UBA1 mutation and bone marrow biopsy. Treatment with oral corticosteroids led to complete resolution of symptoms, both ophthalmologically and systemically, and tocilizumab was later added as a second line immunosuppression steroid-sparing agent.

CONCLUSIONS

This case emphasises the importance of considering VEXAS syndrome in the diagnosis of patients with recurrent orbital and ocular inflammation. It also reiterates the effectiveness of corticosteroids and tocilizumab association in managing this complex condition, contributing to the growing understanding of VEXAS syndrome and its ophthalmological features.

Neutrophilic Urticarial Dermatosis: A Window into Systemic Inflammation and Autoimmune Disorders

Neutrophilic urticarial dermatosis (NUD) is a distinctive dermatological manifestation that is commonly associated with systemic autoinflammatory and autoimmune diseases. This review comprehensively explores NUD in the context of five major conditions: Schnitzler syndrome, Still's disease, cryopyrin-associated periodic syndrome, systemic lupus erythematosus, and VEXAS syndrome. For each condition, a detailed discussion of the underlying mechanisms, clinical presentations, diagnostic criteria, and treatment strategies is provided. In addition, cases exhibiting features similar to NUD are emphasized, with a comprehensive examination of the pathological characteristics, particularly focusing on neutrophilic epitheliotropism. This review underscores the significance of identifying NUD as a potential indicator of systemic autoimmune disorders and discusses the role of skin biopsy and laboratory tests in diagnosing the underlying etiology. Finally, a diagnostic framework for NUD is proposed, highlighting the importance of a multidisciplinary assessment to ascertain the underlying systemic condition responsible for the dermatological manifestations. The objective of this review is to enhance the comprehension of NUD, thereby facilitating early diagnosis and the implementation of targeted strategies for affected patients.

VEXAS syndrome: A newly identified X-Linked hematoinflammatory disorder - A comprehensive overview of its genetic, molecular, inflammatory, and clinical landscape

VEXAS (Vacuoles, E1 Enzyme, X-linked, Auto-inflammatory, Somatic) syndrome is a recently identified auto-inflammatory disorder predominantly affecting males over the age of 50. It arises due to somatic mutations in the UBA1 gene, an X-linked gene essential for initiating the ubiquitin-proteasome system, leading to dysregulated protein degradation and immune dysfunction. Clinically, VEXAS presents with a diverse array of inflammatory manifestations, including persistent fever, neutrophilic dermatosis, auricular and nasal chondritis, pulmonary infiltrates, ocular inflammation, and venous thrombosis, along with significant haematological abnormalities such as macrocytic anemia, thrombocytopenia, myeloid and erythroid precursor vacuolization, and bone marrow dysplasia. These systemic complications contribute to high morbidity and mortality. Currently, therapeutic strategies remain largely undefined, with treatment focusing on two primary approaches, which are modulating inflammation through corticosteroids, JAK inhibitors, or IL-6 blockade and targeting the mutant hematopoietic clone or allogeneic hematopoietic stem cell transplantation (AHSCT) therapies. Supportive interventions, including red blood cell and platelet transfusions, erythropoiesis-stimulating agents, thromboprophylaxis, and antimicrobial prophylaxis, are crucial in managing disease-associated complications. This review aims to present a comprehensive analysis of VEXAS syndrome, focusing on its genetic underpinnings, pathophysiology, clinical manifestations, diagnostic criteria, and evolving therapeutic strategies. By integrating current findings from the literature and identifying gaps in ongoing research, this review seeks to equip clinicians and researchers with a comprehensive understanding of VEXAS syndrome. Additionally, it aims to guide future investigations toward refining diagnostic strategies, optimizing therapeutic approaches, and ultimately improving patient care and clinical outcomes.

Emerging treatment approaches for VEXAS syndrome: a systematic review and meta-analysis

VEXAS (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic) syndrome is a monogenic autoinflammatory disorder with significant morbidity and mortality. Numerous treatment options including azacitidine, JAK inhibitors, IL-6 inhibitors, anti-IL-1, and anti-TNF agents have been proposed. However, no consensus on optimal treatment algorithm has been reached. This study aims to evaluate the efficacy and safety of medical treatment options through a meta-analysis of existing data to help establish clearer guidelines for managing VEXAS. The study protocol was registered in PROSPERO (CRD42024590134). MEDLINE and EMBASE were screened from inception until March 2025. We included patients with VEXAS syndrome who received treatment with azacitidine, JAK inhibitors, IL-6 inhibitors, anti-IL-1, or anti-TNF agents. The primary outcome was the proportion of complete responders. Partial response and reported adverse events were also evaluated. A total of 16 studies and 367 patients with VEXAS syndrome were included. Concomitant myelodysplastic syndrome (MDS) was reported in 149 (40.6%) patients. Azacitidine treatment resulted in complete and partial response in 67% [95% CI (0.56,0.77)] and in 73% [95% CI (0.64,0.82)] of cases, respectively. JAK inhibitors produced a complete response in 42% [95% CI (0.33,0.52)] and partial response in 79% [95% CI (0.71,0.87)]. IL-6 inhibitors led to a complete response in 24% [95% CI (0.15,0.32)] and partial response in 72% [95% CI (0.64,0.81)]. Adverse events were frequently observed. Azacitidine demonstrated significant efficacy in patients with MDS. JAK inhibitors and IL-6 inhibitors may also be viable treatment options. Prospective clinical trials are needed for further confirmation of the results.

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

Vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic (VEXAS) syndrome is a late-onset autoinflammatory disorder caused by somatic mutations in the ubiquitin-attaching protein 1 (UBA1) gene. It primarily affects men aged over 50. We report a middle-aged man presenting with bilateral orbital inflammation, sixth nerve palsy, relapsing polychondritis, sensorineural hearing loss, possible vestibulopathy and a papulovesicular rash. He had macrocytic anaemia and elevated inflammatory markers, but normal autoimmune and infective screens. Imaging identified features of orbital pseudotumour. Genetic testing confirmed a UBA1 p.Met41Thr mutation, confirming VEXAS syndrome. We gave intravenous methylprednisolone, then oral prednisolone and subsequently tocilizumab. This case highlights the multisystem presentation and rare neurological manifestations of VEXAS syndrome and emphasises the importance of genetic testing in its diagnosis. Current treatment options include corticosteroids, interleukin-6 inhibitors and Janus kinase inhibitors, with haematopoietic stem cell transplantation offering curative potential.

Clinical features and treatments of VEXAS syndrome in critical care: a scoping review

BACKGROUND

Vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic (VEXAS) syndrome is a recently discovered severe disorder that predominantly affects adult males, characterized by systemic inflammation and hematologic abnormalities. Despite its profound impact on patient outcomes, awareness of VEXAS syndrome among critical care providers remains severely limited, often leading to delayed recognition, diagnosis, and initiation of appropriate treatment. This study aims to address this knowledge gap by conducting a scoping review on VEXAS syndrome in the critical care setting.

METHODS

This scoping review followed the PRISMA-ScR guidelines and Joanna Briggs Institute methodology, analyzing data from Cochrane CENTRAL, MEDLINE via PubMed, EMBASE, and Web of Science on May 19, 2024. We included studies that reported clinical features and treatments of patients with VEXAS syndrome requiring critical care.

RESULTS

Of the 1262 reports identified, 78 reports met the inclusion criteria, including 45 case reports/series, 17 observational studies, 15 reviews, and one systematic review. Analysis of 55 cases revealed a median age of 69 with a strong male predominance (54/55). ICU admission rates ranged from 28 to 33%, with mortality rates between 18 and 40%. Critical manifestations included shock, hemophagocytic lymphohistiocytosis, acute respiratory distress syndrome, thrombosis, and airway edema. Sepsis was the leading cause of death, followed by other causes including VEXAS syndrome related organ failure, cardiovascular events, and intestinal perforation. Treatment approaches combined conventional critical care measures with immunosuppressive and immunomodulatory therapies, although infectious complications were frequently reported.

CONCLUSION

This review revealed the lack of systematically analyzed studies focusing on VEXAS syndrome in the critical care setting, suggesting a significant gap in understanding the clinical characteristics and optimal treatments for VEXAS syndrome. Further research focused on VEXAS syndrome in the critical care setting is essential to improve early recognition, develop standardized treatment protocols, and ultimately improve patient outcomes in this complex patient population.

Myeloid neoplasm inspired intensive therapy in VEXAS syndrome: A single-centre experience

There is still no standard of care and unmet medical needs in refractory/advanced VEXAS (vacuoles in myeloid progenitors, E1 ubiquitin activating enzyme, X-linked, autoinflammatory manifestations and somatic) syndrome with or without associated haematological neoplasm. We report the clinical outcome of four multirefractory/advanced VEXAS patients treated with acute myeloid leukaemia-like therapeutic approaches. All patients responded to inflammatory/haematological VEXAS-related features, which were associated with measurable residual disease response (partial or complete). Prospective studies evaluating new and effective therapeutic strategies in order to reduce clonal burden in VEXAS patients are warranted.

[VEXAS-like auto inflammatory syndrome: 2 cases]

INTRODUCTION

VEXAS syndrome (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic), recently described, due to a somatic mutation of the UBA1 gene and often associated with hemopathy, is characterized by systemic symptoms close to those described in Still's disease or relapsing polychondritis. There are also patients with hemopathy, presenting inflammatory symptoms reminiscent of those of VEXAS syndrome but without mutation of the UBA1 gene.

CASE/DISCUSSION

Two male patients consulted for general signs, dermatological symptoms, arthralgia, chondritis and venous thrombosis, like patients in the French cohort suffering from VEXAS syndrome. The myelogram found vacuoles in the myeloid and erythroid precursors, with a diagnosis of chronic myelomonocytic leukemia for one and myelodysplastic syndrome for the other. The search for a mutation of the UBA1 gene by the sanger technique, the next-generation sequencing (NGS) analysis of a myeloid panel and the complete sequencing was negative, not allowing the diagnosis of VEXAS syndrome to be retained. There were other somatic mutations, indicating clonal hematopoiesis associated with this systemic inflammatory state. Initial corticosteroid therapy was effective but corticosteroid dependence required sparing treatment with hypomethylating agents or Janus Kinase inhibitors.

CONCLUSION

The role of somatic mutations in the pathophysiology of autoinflammatory diseases associated with hematologic diseases must be better understood in order to better characterize them and develop targeted treatments.

Efficacy and safety profile of biotechnological agents and Janus kinase inhibitors in VEXAS syndrome: data from the international AIDA Network VEXAS registry

BACKGROUND

VEXAS syndrome, a recently identified systemic autoinflammatory disorder, poses new diagnostic and management challenges. Based on experience with other autoinflammatory diseases, anti-interleukin (IL)-1, anti-IL-6, anti-tumor necrosis factor (TNF) biotechnological agents, and Janus kinase inhibitors (JAKis) have been widely employed in VEXAS patients. The aim of this study is to evaluate the global effectiveness and safety of biotechnological agents and JAKis using data from the real-world context.

METHODS

Clinical, laboratory, and therapeutic data from VEXAS patients were obtained from the international AIDA Network VEXAS registry.

RESULTS

In total, 69 VEXAS patients were enrolled in the study. Among them, 12 patients (13 treatment courses) received IL-1 inhibitors, 12 patients (13 treatment courses) were administered anti-IL-6 agents, 8 patients (9 treatment courses) were treated with anti-TNF agents, and 16 patients (17 treatment courses) were treated with JAKis. A complete response was observed in 3 patients (23%) treated with anti-IL-1 agents, 2 patients (15%) receiving IL-6 inhibitors, 1 patient (11%) receiving TNF inhibitors, and 4 patients (23.5%) treated with JAKis. The mean prednisone (or equivalent) dosage significantly decreased during anti-IL-1 treatment (p = 0.01), while glucocorticoids changed during anti-IL-6, anti-TNF, and JAKi treatment in a non-significant fashion. A total of 21 patients experienced adverse events, 3 of which led to death (gut perforation, Legionnaires' disease, and infectious pneumonia) while on JAKis; treatment withdrawal was required for 8 out of 21 patients.

CONCLUSION

IL-1 and IL-6 inhibitors, along with JAKis, represent promising therapeutic options for VEXAS patients, albeit careful monitoring is mandatory to control disease activity and ensure safety.

Neurological manifestations in patients with VEXAS syndrome

BACKGROUND

VEXAS syndrome (Vacuoles, E1 enzyme, X-linked, Autoinflammatory, Somatic) is a recently described syndrome linked to somatic mutations in the UBA1 gene, causing systemic autoinflammatory manifestations. To date, few data are available concerning neurological manifestations. The aim of this study was to describe their prevalence, clinical spectrum and outcome under treatment.

METHODS

Retrospective multicentre study including patients with VEXAS syndrome from the French VEXAS Registry between November 2020 and March 2023. Additional cases were included after a national call for observations. Each patient with confirmed UBA1 somatic mutation and neurological manifestation was reviewed during multidisciplinary meetings. Clinical, radiological, biological characteristics, treatments, and outcome were described.

RESULTS

Of the 291 patients included in the French VEXAS Registry, 17 (6%) had central (CNS) or peripheral (PNS) neurological involvement, with 13 additional cases identified by the national call. Of the 30 patients included, 21 (70%) had PNS involvement and 9 (30%) CNS involvement. PNS involvements included polyneuropathy (n = 9), cranial nerve involvement (n = 7), non-length-dependent polyneuropathy (n = 5) and multiple mononeuropathy (n = 3). CNS involvements included encephalopathy (n = 6), lacunar cerebral infarcts (n = 4), posterior reversible encephalopathy syndrome (n = 3) and optic perineuritis (n = 2). Most neurological manifestations were improved by steroids (68%), steroid-sparing agents were used in 90% [most frequently ruxolitinib (n = 11), azacitidine (n = 8), tocilizumab (n = 4)], and mortality was 30% after a median follow-up of 4 years.

CONCLUSIONS

Neurological manifestations may occur in a small but possibly underestimated proportion of patients with VEXAS syndrome, are heterogeneous and can involve both PNS and CNS.

Clinical Challenges of Emerging Acquired Autoinflammatory Diseases, Including VEXAS Syndrome

Vacuoles, E1-ubiquitin-activating enzyme, X-linked, autoinflammatory, somatic (VEXAS) syndrome, caused by an acquired mutation in the ubiquitin-activating enzyme ubiquitin-like modifier activating enzyme 1 (UBA1), was discovered in 2020. Since then, many cases have been reported worldwide. Recently, we performed UBA1 genetic testing in suspected cases of VEXAS throughout Japan and investigated the clinical features of these cases. Most cases were elderly patients in their 70s with clinical features consistent with VEXAS syndrome, such as myelodysplastic syndrome, high-grade fever, skin rash, chondritis, and pulmonary infiltration. However, approximately half of the analyzed patients were negative for the UBA1 variant. As the concept of "acquired autoinflammatory diseases," including VEXAS syndrome, has gained popularity, the number of suspected cases is expected to increase. Currently, there are no established diagnostic or treatment guidelines for these conditions, and they need to be urgently developed. This review summarizes the clinical problems faced by patients with acquired autoinflammatory diseases, including VEXAS.

VEXAS Syndrome: A Comprehensive Review of Current Therapeutic Strategies and Emerging Treatments

VEXAS syndrome is a recently identified autoinflammatory disorder resulting from somatic mutations in the UBA1 gene, leading to a complex spectrum of severe inflammatory and hematologic manifestations. The absence of established treatment guidelines and the variability in clinical presentation make its management particularly challenging. Current therapeutic approaches are often based on limited evidence, and their effectiveness remains inconsistent. This review seeks to consolidate the existing knowledge on therapeutic strategies for VEXAS syndrome, offering a critical evaluation of their efficacy and addressing the gaps in the current literature. As the clinical recognition of VEXAS grows, there is an urgent need to explore more targeted, effective treatments that can address both the inflammatory and hematologic aspects of the disease. By providing a comprehensive analysis of the current therapeutic landscape, this review aims to guide clinicians and researchers toward developing more effective, long-term management strategies for this life-threatening condition.

Case report: VEXAS syndrome with excellent response to treatment with azacitidine

Vacuoles, E1 enzyme, X-linked, auto inflammatory, somatic (VEXAS) syndrome is an inflammatory disorder caused by somatic UBA1 variants and is characterized by late-onset systemic autoimmune inflammation and blood abnormalities. Glucocorticoids ameliorate symptoms effectively. However, other treatment options have limited efficacy and a transient effect. Herein, we describe a case of a 69-year-old male patient with VEXAS syndrome with skin, lung and hematologic involvement. He was treated with glucocorticoids and after the failure with anti IL-1 he began treatment with azacitidine with excellent hematological and clinical response. Azacitidine may be a suitable option for treating VEXAS syndrome, especially due to the relationship between inflammatory symptoms and response to azacitidine.

Clinical exome sequencing data from patients with inborn errors of immunity: Cohort level diagnostic yield and the benefit of systematic reanalysis

While next generation sequencing has expanded the scientific understanding of Inborn Errors of Immunity (IEI), the clinical use and re-use of exome sequencing is still emerging. We revisited clinical exome data from 1300 IEI patients using an updated in silico IEI gene panel. Variants were classified and curated through expert review. The molecular diagnostic yield after standard exome analysis was 11.8 %. Through systematic reanalysis, we identified variants of interest in 5.2 % of undiagnosed patients, with 76.7 % being (candidate) disease-causing, providing a (candidate) diagnosis in 15.2 % of our cohort. We find a 1.7 percentage point increase in conclusive molecular diagnoses. We find a high degree of actionability in patients with a genetic diagnosis (76.4 %). Despite the modest absolute diagnostic gain, these data support the benefit of iterative exome reanalysis in IEI patients, conveying the notion that our current understanding of genes and variants involved in IEI is by far not saturated.

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.

Efficacy and safety of targeted therapies in VEXAS syndrome: retrospective study from the FRENVEX

OBJECTIVES

Vacuoles, E1 enzyme, X-linked, autoinflammatory and somatic (VEXAS) syndrome is an adult-onset autoinflammatory disease associated with somatic ubiquitin-like modifier-activating enzyme 1 (UBA1) mutations. We aimed to evaluate the efficacy and safety of targeted therapies.

METHODS

Multicentre retrospective study including patients with genetically proven VEXAS syndrome who had received at least one targeted therapy. Complete response (CR) was defined by a clinical remission, C-reactive protein (CRP) ≤10 mg/L and a ≤10 mg/day of prednisone-equivalent therapy, and partial response (PR) was defined by a clinical remission and a 50% reduction in CRP levels and glucocorticoid dose.

RESULTS

110 patients (median age 71 (68-79) years) who received 194 targeted therapies were included: 78 (40%) received Janus kinase (JAK) inhibitors (JAKi), 51 (26%) interleukin (IL)-6 inhibitors, 33 (17%) IL-1 inhibitors, 20 (10%) tumour necrosis factor (TNFα) blockers and 12 (6%) other targeted therapies. At 3 months, the overall response (CR and PR) rate was 24% with JAKi, 32% with IL-6 inhibitors, 9% with anti-IL-1 and 0% with TNFα blockers or other targeted therapies. At 6 months, the overall response rate was 30% with JAKi and 26% with IL-6 inhibitors. Survival without treatment discontinuation was significantly longer with JAKi than with the other targeted therapies. Among patients who discontinued treatment, causes were primary failure, secondary failure, serious adverse event or death in 43%, 14%, 19% and 19%, respectively, with JAKi and 46%, 11%, 31% and 9%, respectively, with IL-6 inhibitors.

CONCLUSIONS

This study shows the benefit of JAKi and IL-6 inhibitors, whereas other therapies have lower efficacy. These results need to be confirmed in prospective trials.

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 clinical phenotype of VEXAS syndrome with pleural effusion, infiltrates, and systemic inflammation in a 76-year-old patient: a case report

INTRODUCTION

VEXAS syndrome, characterized by a UBA1 gene mutation, is a rare and severe systemic inflammatory disease predominantly affecting men. Since its initial description in 2020, it has been noted for its broad clinical phenotype and frequent misdiagnosis.

CASE PRESENTATION

A 76-year-old Caucasian male patient diagnosed with VEXAS syndrome is presented in this case report. He presented with typical symptoms including pulmonary manifestations (infiltrates and effusions), systemic inflammation, and haematological abnormalities. The diagnosis was challenging due to the disease's heterogeneous presentation, often resembling autoimmune or haematological diseases. This patient's case featured ground-glass opacities and pleural effusions, underlining the significant pulmonary involvement seen in 50-67% of VEXAS patients. His condition was further complicated by recurrent fever and systemic inflammation affecting multiple organs.

CONCLUSION

VEXAS syndrome demands an aggressive treatment approach due to its high mortality rate and refractory nature. This case underscores the importance of including VEXAS syndrome in differential diagnoses, particularly for patients with systemic inflammation and pulmonary symptoms, and calls for multidisciplinary management and extensive research to understand its full range of clinical phenotypes.

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.

Central nervous system vasculitis in VEXAS syndrome: A rare involvemen

INTRODUCTION

VEXAS (Vacuoles, E1 Enzyme, X-linked, autoinflammatory, Somatic) syndrome is a recently described severe adult-onset autoinflammatory disorder mediated by X-linked gene UBA1 somatic mutations, responsible of recurrent fever, skin involvement, chondritis, macrocytic anemia and inflammatory syndrome. Neurological manifestations are rarely described, and predominantly involve peripheral nervous system (PNS) impairment.

RESULTS

We report the first central nervous system (CNS) vasculitis in VEXAS syndrome, characterized by headache, cognitive dysfunction and focal signs (cerebellar ataxia). Magnetic resonance imaging (MRI) revealed multifocal white-matter lesions corresponding to recent ischemic strokes, combined with cortical hemorrhagic lesions and gadolinium enhancement of the distal wall vessels. Treatment with methylprednisone, ruxolitinib and tocilizumab led to clinical improvement and a decrease of the inflammatory syndrome. The patient died few months after due to infectious complications.

CONCLUSION

CNS vasculitis, occurring as a manifestation of the systemic auto-inflammatory state of VEXAS syndrome, might be a rare but severe complication. We suggest that it be added to the list of inflammatory vasculopathies. More prospective studies are needed to optimize the treatment.

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.

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.

Successful treatment with fludarabine and cyclophosphamide in a VEXAS syndrome patient with associated myelodysplastic syndrome: a case report and systematic review

Vacuoles, E1 syndrome, X-linked, autoinflammatory, somatic (VEXAS) syndrome is a chronic inflammatory disorder that affects various organ systems. It is associated with hematologic malignancies and is generally refractory to therapies. Allogeneic hematopoietic stem cell transplantation (allo-HSCT) may be considered for selected patients. We report a case wherein systemic and hematological manifestations completely resolved in a patient with VEXAS and associated myelodysplastic syndrome (MDS), following the administration of fludarabine and cyclophosphamide as part of the preparation for allo-HSCT. We conducted a systematic literature review and included 86 patients with VEXAS syndrome and associated MDS. Most cases presented with musculoskeletal involvement (71%) and anemia (72%) with lower-risk MDS. Most patients responded to corticosteroids (CS) but had a recurrence of symptoms with CS taper and were refractory to other immunosuppressive agents. Hypomethylating agents and Janus kinase inhibitors achieved a complete response in some cases. Further research is needed to develop more effective treatment strategies.

[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 Swiss national retrospective cohort study

STUDY AIMS

VEXAS syndrome is a recently discovered monogenic auto-inflammatory disease caused by a somatic mutation in the UBA1 gene that manifests with rheumatologic and haematologic features. In this report, we present the first Swiss cohort, detailing its manifestations and treatment outcomes among Swiss patients.

METHODS

Data were retrospectively collected from nine hospitals across Switzerland, representing a broad geographic distribution. Treating physicians completed a standardised case report form for each patient. The principal investigator and the co-investigators collected and analysed all case report forms.

RESULTS

We identified 23 patients between July 2022 and 2023, of which 17 are described. All were male. They presented with skin manifestations (88%), general symptoms (82%), venous thromboembolism (59%), ocular manifestation (59%), lung infiltrates (59%) and articular manifestations (47%). Central nervous system and kidney manifestations were very rare, and heart and digestive manifestations were absent. Macrocytic anaemia was present in all patients throughout the disease progression but only in two-thirds of patients (12/17, 71%) at the time of diagnosis. Clinical response was reached in all cases treated with ruxolitinib (4/4, 100%), upadacitinib (1/1, 100%), azacytidine (5/5, 100%) and haematopoietic stem cell transplantation (2/2, 100%). All deaths were attributed to infections (5/5, 100%).

CONCLUSION

This study corroborates the clinical spectrum of VEXAS syndrome described in other cohorts. It suggests that VEXAS syndrome is not limited to patients with macrocytic anaemia. In this study, azacytidine has been used effectively among patients with myelodysplastic syndrome. In addition, Janus kinase (JAK) inhibitors, particularly ruxolitinib, have been successfully used even in those without myelodysplastic syndrome. We report two successful treatments by haematopoietic stem cell transplantation.

VEXAS syndrome: complete molecular remission after hypomethylating therapy

The VEXAS syndrome, a genetically defined autoimmune disease, associated with various hematological neoplasms has been attracting growing attention since its initial description in 2020. While various therapeutic strategies have been explored in case studies, the optimal treatment strategy is still under investigation and allogeneic cell transplantation is considered the only curative treatment. Here, we describe 2 patients who achieved complete molecular remission of the underlying UBA1 mutant clone outside the context of allogeneic HCT. Both patients received treatment with the hypomethylating agent azacitidine, and deep molecular remission triggered treatment de-escalation and even cessation with sustained molecular remission in one of them. Prospective studies are necessary to clarify which VEXAS patients will benefit most from hypomethylating therapy and to understand the variability in the response to different treatment strategies.

Serious infections in patients with VEXAS syndrome: data from the French VEXAS registry

INTRODUCTION

Vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic (VEXAS) syndrome is an acquired autoinflammatory monogenic disease with a poor prognosis whose determinants are not well understood. We aimed to describe serious infectious complications and their potential risk factors.

METHODS

Retrospective multicentre study including patients with VEXAS syndrome from the French VEXAS Registry. Episodes of serious infections were described, and their risk factors were analysed using multivariable Cox proportional hazards models.

RESULTS

Seventy-four patients with 133 serious infections were included. The most common sites of infection were lung (59%), skin (10%) and urinary tract (9%). Microbiological confirmation was obtained in 76%: 52% bacterial, 30% viral, 15% fungal and 3% mycobacterial. Among the pulmonary infections, the main pathogens were SARS-CoV-2 (28%), Legionella pneumophila (21%) and Pneumocystis jirovecii (19%). Sixteen per cent of severe infections occurred without any immunosuppressive treatment and with a daily glucocorticoid dose ≤10 mg. In multivariate analysis, age >75 years (HR (95% CI) 1.81 (1.02 to 3.24)), p.Met41Val mutation (2.29 (1.10 to 5.10)) and arthralgia (2.14 (1.18 to 3.52)) were associated with the risk of serious infections. JAK inhibitors were most associated with serious infections (3.84 (1.89 to 7.81)) compared with biologics and azacitidine. After a median follow-up of 4.4 (2.5-7.7) years, 27 (36%) patients died, including 15 (56%) due to serious infections.

CONCLUSION

VEXAS syndrome is associated with a high incidence of serious infections, especially in older patients carrying the p.Met41Val mutation and treated with JAK inhibitors. The high frequency of atypical infections, especially in patients without treatment, may indicate an intrinsic immunodeficiency.

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.

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.

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.

Ribonucleotide reductase M2 (RRM2): Regulation, function and targeting strategy in human cancer

Ribonucleotide reductase M2 (RRM2) is a small subunit in ribonucleotide reductases, which participate in nucleotide metabolism and catalyze the conversion of nucleotides to deoxynucleotides, maintaining the dNTP pools for DNA biosynthesis, repair, and replication. RRM2 performs a critical role in the malignant biological behaviors of cancers. The structure, regulation, and function of RRM2 and its inhibitors were discussed. RRM2 gene can produce two transcripts encoding the same ORF. RRM2 expression is regulated at multiple levels during the processes from transcription to translation. Moreover, this gene is associated with resistance, regulated cell death, and tumor immunity. In order to develop and design inhibitors of RRM2, appropriate strategies can be adopted based on different mechanisms. Thus, a greater appreciation of the characteristics of RRM2 is a benefit for understanding tumorigenesis, resistance in cancer, and tumor microenvironment. Moreover, RRM2-targeted therapy will be more attention in future therapeutic approaches for enhancement of treatment effects and amelioration of the dismal prognosis.

Sensitivity to targeted UBA1 inhibition in a myeloid cell line model of VEXAS syndrome

Somatic UBA1 mutations in hematopoietic cells are a hallmark of Vacuoles, E1 enzyme, X-linked, Autoinflammatory, Somatic (VEXAS) syndrome, which is a late-onset inflammatory disease associated with bone marrow failure and high mortality. The majority of UBA1 mutations in VEXAS syndrome comprise hemizygous mutations affecting methionine-41 (M41), leading to the expression of UBA1M41T, UBA1M41V, or UBA1M41L and globally reduced protein polyubiquitination. Here, we used CRISPR-Cas9 to engineer isogenic 32D mouse myeloid cell lines expressing hemizygous Uba1WT or Uba1M41L from the endogenous locus. Consistent with prior analyses of patients with VEXAS syndrome samples, hemizygous Uba1M41L expression was associated with loss of the UBA1b protein isoform, gain of the UBA1c protein isoform, reduced polyubiquitination, abnormal cytoplasmic vacuoles, and increased production of interleukin-1β and inflammatory chemokines. Vacuoles in Uba1M41L cells contained a variety of endolysosomal membranes, including small vesicles, multivesicular bodies, and multilamellar lysosomes. Uba1M41L cells were more sensitive to the UBA1 inhibitor TAK243. TAK243 treatment promoted apoptosis in Uba1M41L cells and led to preferential loss of Uba1M41L cells in competition assays with Uba1WT cells. Knock-in of a TAK243-binding mutation, Uba1A580S, conferred TAK243 resistance. In addition, overexpression of catalytically active UBA1b in Uba1M41L cells restored polyubiquitination and increased TAK243 resistance. Altogether, these data indicate that loss of UBA1b underlies a key biochemical phenotype associated with VEXAS syndrome and renders cells with reduced UBA1 activity vulnerable to targeted UBA1 inhibition. Our Uba1M41L knock-in cell line is a useful model of VEXAS syndrome that will aid in the study of disease pathogenesis and the development of effective therapies.

Genetic Characteristics of Patients with Young-Onset Myelodysplastic Neoplasms

Myelodysplastic neoplasm (MDS) is a heterogeneous group of myeloid neoplasms affected by germline and somatic genetic alterations. The incidence of MDS increases with age but rarely occurs at a young age. We investigated the germline and somatic genetic alterations of Korean patients with young-onset MDS (<40 years). Among the thirty-one patients, five (16.1%) had causative germline variants predisposing them to myeloid neoplasms (three with GATA2 variants and one each with PGM3 and ETV variants). We found that PGM3 deficiency, a subtype of severe immunodeficiency, predisposes patients to MDS. Somatic mutations were identified in 14 patients (45.2%), with lower rates in patients aged < 20 years (11.1%). Nine (29%) patients had U2AF1 S34F/Y mutations, and patients with U2AF1 mutations showed significantly worse progression-free survival (p < 0.001) and overall survival (p = 0.006) than those without U2AF1 mutations. A UBA1 M41T mutation that causes VEXAS syndrome was identified in a male patient. In conclusion, a germline predisposition to myeloid neoplasms occurred in ~16% of young-onset MDS patients and was largely associated with primary immunodeficiencies, including GATA2 deficiency. Furthermore, the high frequency of somatic U2AF1 mutations in patients with young-onset MDS suggests the presence of a distinct MDS subtype.

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.

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.

Spanish cohort of VEXAS syndrome: clinical manifestations, outcome of treatments and novel evidences about UBA1 mosaicism

BACKGROUND

The vacuoles, E1-enzyme, X linked, autoinflammatory and somatic (VEXAS) syndrome is an adult-onset autoinflammatory disease (AID) due to postzygotic UBA1 variants.

OBJECTIVES

To investigate the presence of VEXAS syndrome among patients with adult-onset undiagnosed AID. Additional studies evaluated the mosaicism distribution and the circulating cytokines.

METHODS

Gene analyses were performed by both Sanger and amplicon-based deep sequencing. Patients' data were collected from their medical charts. Cytokines were quantified by Luminex.

RESULTS

Genetic analyses of enrolled patients (n=42) identified 30 patients carrying UBA1 pathogenic variants, with frequencies compatible for postzygotic variants. All patients were male individuals who presented with a late-onset disease (mean 67.5 years; median 67.0 years) characterised by cutaneous lesions (90%), fever (66.7%), pulmonary manifestations (66.7%) and arthritis (53.3%). Macrocytic anaemia and increased erythrocyte sedimentation rate and ferritin were the most relevant analytical abnormalities. Glucocorticoids ameliorated the inflammatory manifestations, but most patients became glucocorticoid-dependent. Positive responses were obtained when targeting the haematopoietic component of the disease with either decitabine or allogeneic haematopoietic stem cell transplantation. Additional analyses detected the UBA1 variants in both haematopoietic and non-haematopoietic tissues. Finally, analysis of circulating cytokines did not identify inflammatory mediators of the disease.

CONCLUSION

Thirty patients with adult-onset AID were definitively diagnosed with VEXAS syndrome through genetic analyses. Despite minor interindividual differences, their main characteristics were in concordance with previous reports. We detected for the first time the UBA1 mosaicism in non-haematopoietic tissue, which questions the previous concept of myeloid-restricted mosaicism and may have conceptual consequences for the disease mechanisms.

Polyarteritis Nodosa: Old Disease, New Etiologies

Polyarteritis nodosa (PAN), also known as panarteritis nodosa, represents a form of necrotizing vasculitis that predominantly affects medium-sized vessels, although it is not restricted to them and can also involve smaller vessels. The clinical presentation is heterogeneous and characterized by a significant number of patients exhibiting general symptoms, including asthenia, fever, and unintended weight loss. Although PAN can involve virtually any organ, it preferentially affects the skin, nervous system, and the gastrointestinal tract. Orchitis is a rare but specific manifestation of PAN. The absence of granulomas, glomerulonephritis, and anti-neutrophil cytoplasmic antibodies serves to distinguish PAN from other types of vasculitis. Major complications consist of hemorrhagic and thrombotic events occurring in mesenteric, cardiac, cerebral, and renal systems. Historically, PAN was frequently linked to hepatitis B virus (HBV) infection, but this association has dramatically changed in recent years due to declining HBV prevalence. Current epidemiological research often identifies a connection between PAN and genetic syndromes as well as neoplasia. This article provides a comprehensive review of PAN, specifically focusing on the progression of its clinical manifestations over time.