Pathogenic UBA1 variants associated with VEXAS syndrome in Japanese patients with relapsing polychondritis

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: 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.

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.

The Histopathology of Vacuoles, E1 Enzyme, X-Linked, Autoinflammatory, Somatic Syndrome: Report of 12 Skin Biopsies From 6 Patients

ABSTRACT

We present the histopathology of 12 skin biopsies from 6 patients with vacuoles, enzyme E1, X-linked, autoinflammatory, somatic syndrome and review the literature. The age of these 6 men ranges from 62 to 83 years (median of 70 years). UBA1 mutation was documented in all 6 patients. Multiple organ systems were involved with constitutional symptoms noted in 4 of 6 patients (67%), cutaneous involvement in 6 of 6 patients (100%), hematologic abnormalities in 6 of 6 patients (100%), pulmonary involvement in 4 of 6 patients (67%), musculoskeletal abnormalities in 3 of 6 patients (50%), vascular thrombosis in 2 of 6 patients (33%), ocular involvement in 2 of 6 patients (33%), and gastrointestinal involvement in 5 of 6 patients (83%). Of the 6 presented patients, neutrophilic dermatosis was seen in 3 biopsies, histiocytoid neutrophilic dermatosis in 1 biopsy, neutrophilic dermatosis with vasculitis in 1 biopsy, neutrophilic and granulomatous dermatitis in 2 biopsies, septal panniculitis consistent with erythema nodosum in 2 biopsies, and nonspecific patterns in 3 biopsies. In summary, neutrophilic dermatosis, small-vessel vasculitis, and panniculitis are frequent histopathologic patterns noted in decreasing frequency in skin biopsies of the patients with vacuoles, enzyme E1, X-linked, autoinflammatory, somatic syndrome. However, the histopathologic findings can be diverse, nonspecific in some instances, and varied among different biopsies obtained from the same patient.

Clinical evaluation of droplet digital pcr for suspected ascites infection in patients with liver cirrhosis

BACKGROUND

Droplet digital PCR (ddPCR) is increasingly used in diagnosing clinical pathogens, but its effectiveness in cirrhosis patients with suspected ascites infection remains uncertain.

METHODS

The diagnostic performance of ddPCR was assessed in 305 ascites samples, utilizing culture and clinical composite standards. The quantitative value and potential clinical impact of ddPCR were further analyzed in patients with spontaneous bacterial peritonitis.

RESULTS

With culture standards, ddPCR demonstrated a sensitivity of 86.5% and specificity of 83.2% for bacterial or fungal detection. After adjustment of clinical composite criteria, specificity increased to 96.4%. Better diagnostic performance for all types of targeted pathogens, particularly fungi, was observed with ddPCR compared to culture, and more polymicrobial infections were detected (30.4% versus 5.7%, p < 0.001). Pathogen loads detected by ddPCR correlated with white blood cell count in ascites and blood, as well as polymorphonuclear cell (PMN) count in ascites, reflecting infection status rapidly. A positive clinical impact of 55.8% (43/77) was observed for ddPCR, which was more significant among patients with PMN count ≤ 250/mm3 in terms of medication adjustment and new diagnosis. ddPCR results for fungal detection were confirmed by clinical symptoms and other microbiological tests, which could guide antifungal therapy and reduce the risk of short-term mortality.

CONCLUSIONS

ddPCR, with appropriate panel design, has advantages in pathogen detection and clinical management of ascites infection, especially for patients with fungal and polymicrobial infections. Patients with atypical spontaneous bacterial peritonitis benefited more from ddPCR.

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.

Clinical and histological features of histiocytoid Sweet syndrome associated with VEXAS syndrome

BACKGROUND

VEXAS (Vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic) syndrome is caused by acquired somatic mutations in UBA1. Sweet-syndrome-like skin disorders [and especially histiocytoid Sweet syndrome (HSS)] may be associated with VEXAS syndrome.

OBJECTIVES

To characterize the clinical and histopathological features of HSS in patients with VEXAS syndrome.

METHODS

Skin biopsies with a histological diagnosis of HSS at Rennes University Medical Center (Rennes, France) between October 2011 and January 2022 were reviewed in this study. Sanger sequencing and digital polymerase chain reaction were used to screen skin, blood and bone marrow samples for UBA1 variants, and thus classify patients as having VEXAS syndrome or not. We evaluated the clinical, histological and molecular (UBA1) characteristics of patients with or without VEXAS syndrome.

RESULTS

We compared 15 skin biopsies from 7 patients found to have VEXAS syndrome and 19 skin biopsies from 15 patients without VEXAS syndrome. Persistent C-reactive protein elevation, macrocytosis, anaemia and haematological malignancies were more prevalent in patients with VEXAS syndrome [6/7 (86%), 6/7 (86%), 7/7 (100%) and 6/7 (86%), respectively] than in patients without [5/14 (36%), 6/15 (40%), 8/15 (53%) and 8/15 (53%), respectively]. These features sometimes appeared after the first skin manifestations, and a UBA1 mutation was found in the skin of five patients with VEXAS syndrome. Dermal infiltration by reniform histiocytoid cells (myeloperoxidase-positive and/or CD163-positive) and a periadnexal distribution were more frequently observed in VEXAS syndrome biopsies [15/15 (100%) and 3/15 (20%), respectively, vs. 11/19 (58%) and 0/19 (0%) in non-VEXAS syndrome biopsies, respectively].

CONCLUSIONS

Our findings might help pathologists to consider a diagnosis of VEXAS syndrome and to initiate early genetic testing.

VEXAS syndrome as a cause for multifocal, relapsing head and neck inflammation

VEXAS syndrome (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic) is a novel autoinflammatory syndrome. We describe a case of VEXAS syndrome with upper airway and oral cavity involvement which are not well described in the literature.

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.

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.

Targeting enhanced cell death represents a potential therapeutic strategy for VEXAS syndrome

Objectives

To unravel the mechanisms underlying cell death in the vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic (VEXAS) syndrome using peripheral blood samples and to assess the clinical value of this knowledge.

Methods

Nine patients undergoing treatment for VEXAS syndrome at Yokohama City University Hospital were included in this study. Monocytes and neutrophils were isolated from peripheral blood and then monocytes were differentiated into polarized macrophages. Viable cell counts, cell death assays and measurements of various indicators such as high mobility group box 1 (HMGB1) concentration, extracellular adenosine triphosphate (ATP) concentration, annexin V level and caspase 1, 3 and 7 activities were performed.

Results

Elevated cell death of monocytes and neutrophils was observed in VEXAS syndrome patients, as indicated by cultured cell counts and cell death assays. Annexin V assays and measurements of caspase 1, 3 and 7 activities suggested increased apoptosis and pyroptosis in these cells. Serum HMGB1 levels were significantly elevated in VEXAS syndrome patients and decreased after prednisolone (PSL) dose escalation. Monocytes and neutrophils from the VEXAS group exhibited heightened extracellular ATP secretion, which was significantly reduced by soluble PSL co-culture.

Conclusion

This study confirms increased cell death of monocytes and neutrophils and damage-associated molecular patterns in VEXAS syndrome, and these findings may be valuable for drug screening, therapeutic strategies and as biomarkers.

[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.

Clonal haematopoiesis across the age spectrum of vasculitis patients with Takayasu's arteritis, ANCA-associated vasculitis and giant cell arteritis

OBJECTIVES

Ageing and inflammation are associated with clonal haematopoiesis (CH), the emergence of somatic mutations in haematopoietic cells. This study details CH in patients with systemic vasculitis in association with clinical, haematological and immunological parameters.

METHODS

Patients with three forms of vasculitis were screened for CH in peripheral blood by error-corrected sequencing. Relative contributions of age and vasculitis on CH prevalence were calculated using multivariable logistic regression. Clonal hierarchies were assessed by proteogenomic single-cell DNA sequencing, and functional experiments were performed in association with CH status.

RESULTS

Patients with Takayasu's arteritis (TAK; n=70; mean age=33.2 years), antineutrophil cytoplasmic antibody-associated vasculitis (AAV; n=47; mean age=55.3 years) and giant cell arteritis (GCA; n=59; mean age=71.2 years) were studied. CH, most commonly in DNMT3A and TET2, was detected in 34% (60/176) of patients versus 18% (28/151) of age-matched controls (p<0.01). Prevalence of CH was independently associated with age (standardised B=0.96, p<0.01) and vasculitis (standardised B=0.46, p<0.01), occurring in 61%, 32% and 13% of patients with GCA, AAV and TAK, respectively. Both branched and linear clonal trajectories showed myeloid-lineage bias, and CH was associated with markers of cellular activation. In GCA, mutations were detected in temporal artery biopsies, and clinical relapse correlated with CH in a dose-dependent relationship with clone size.

CONCLUSIONS

Age was more strongly associated with CH prevalence than inflammation in systemic vasculitis. Clonal profile was dominated by DNMT3A mutations which were associated with relapse in GCA. CH is not likely a primary causal factor in systemic vasculitis but may contribute to inflammation.

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.

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 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.

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.

Thrombosis in Myeloid Malignancies: From CHIP to AML

The development of myeloid malignancies is a multi-step process starting from pre-malignant stages. Large-scale studies on clonal hematopoiesis of indeterminate potential (CHIP) identified this condition as a risk factor for developing hematologic malignancies, in particular myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML). In parallel, CHIP was found to confer an enhanced thrombotic risk, in particular for cardiovascular diseases. In a similar fashion, in recent years, alongside their life-threatening features, increasing attention has been drawn toward thrombotic complications in myeloid malignancies. Thus, the purpose of this review is to gather a growing body of evidence on incidence, pathogenesis and clinical impact of thrombosis in myeloid malignancies at every step of malignant progression, from CHIP to AML.

Long-term remission of VEXAS syndrome achieved by a single course of CHOP therapy: A case report

We herein describe the case of a 52-year-old male patient who presented with fever, arthritis, and neutrophilic dermatosis in 2013 and subsequently experienced macrophage activation syndrome treated with high-dose glucocorticoid therapy. Due to the persistent symptoms refractory to several immunomodulatory and immunosuppressive (IS) drug therapies with dapsone, methotrexate, tacrolimus, infliximab (IFX), and tocilizumab (TCZ), he received prednisolone (PSL) ≥20 mg/day to suppress disease activity. In 2017, Epstein-Barr virus (EBV)-associated haemophagocytic lymphohistiocytosis (HLH) was diagnosed and initially treated with immunochemotherapy consisting of dexamethasone, cyclosporine (CyA), and etoposide (ET). Because of the suboptimal response to the initial therapy, cytoreduction therapy consisting of CHOP (combination chemotherapy consisting of cyclophosphamide, doxorubicin, vincristine, and PSL) was administered. This regimen improved the EBV-associated HLH. Later, the patient's condition stabilised with methylprednisolone 1 mg/day and CyA 100 mg/day. In 2022, ubiquitylation-initiating E1 enzyme (UBA1) variant analysis using Sanger sequencing of peripheral blood leukocytes detected a previously reported somatic variant (NM_003334.3: c.118-1G>C), confirming the diagnosis of vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic (VEXAS) syndrome. The clinical course in the present case suggested the possibility that CHOP could be a potential treatment option for VEXAS syndrome, in the pathophysiology of which the expansion of clones with UBA1 variant seems to play a pivotal role.

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.

Clinical and genetic features of Japanese cases of MDS associated with VEXAS syndrome

VEXAS (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic) syndrome is a new disease entity with autoinflammatory disorders (AID) driven by somatic variants in UBA1 that frequently co-exists with myelodysplastic syndromes (MDS). Clinicopathological and molecular features of Japanese cases with VEXAS-associated MDS remain elusive. We previously reported high prevalence of UBA1 variants in Japanese patients with relapsing polychondritis, in which 5 cases co-occurred with MDS. Here, we report clinicopathological and variant profiles of these 5 cases and 2 additional cases of MDS associated with VEXAS syndrome. Clinical characteristics of these cases included high prevalence of macrocytic anemia with marked cytoplasmic vacuoles in myeloid/erythroid precursors and low bone marrow (BM) blast percentages. All cases were classified as low or very low risk by the revised international prognostic scoring system (IPSS-R). Notably, 4 out of 7 cases showed significant improvement of anemia by treatment with prednisolone (PSL) or cyclosporin A (CsA), suggesting that an underlying inflammatory milieu induced by VEXAS syndrome may aggravate macrocytic anemia in VEXAS-associated MDS. Targeted deep sequencing of blood samples suggested that MDS associated with VEXAS syndrome tends to involve a smaller number of genes and lower risk genetic lesions than classical MDS.

[Autoinflammatory syndromes]

The concept of autoinflammation includes a heterogeneous group of monogenic and polygenic diseases. These are characterized by excessive activation of the innate immune system without antigen-specific T cells or autoantibodies. The diseases are characterized by periodic episodes of fever and increased inflammation parameters. Monogenic diseases include familial Mediterranean fever (FMF) and the newly described VEXAS (vacuoles, E1 enzyme, X‑linked, autoinflammatory, somatic) syndrome. Heterogeneous diseases include adult-onset Still's disease and Schnitzler syndrome. Treatment is aimed at preventing the excessive inflammatory reaction in order to avoid long-term damage, such as amyloid A (AA) amyloidosis.

Episcleritis and periorbital edema secondary to VEXAS syndrome

VEXAS (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic) syndrome is a newly described autoinflammatory entity caused by a UBA-1 gene mutation. Among the most frequent symptoms it produces fever, cytopenias, polychondritis, pulmonary infiltrates and up to 40% ocular involvement such as periorbital edema, uveitis, episcleritis, scleritis and retinal vasculitis. Patients respond to high doses of corticosteroids, however, many end up being refractory to them and to the classic immunosuppressants. We described the case of a 77-year-old male patient with ocular involvement in the form of episcleritis and periorbital edema who was later diagnosed with VEXAS Syndrome. The patient, after failing treatment with immunosuppressants, is currently receiving treatment with oral steroids and tocilizumab. Ophthalmologist must be aware of the ophthalmological affectation of autoinflammatory diseases and especially of this new entity described as the VEXAS Syndrome.

VEXAS Syndrome-Review

VEXAS (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic) syndrome is a newly defined refractory adult-onset autoinflammatory syndrome caused by somatic mutations in the ubiquitin-like modifier-activating enzyme 1 (UBA1) gene in hematopoietic stem and progenitor cells, resulting in a shift in UBA1 isoform expression. Thus, patients develop a spectrum of systemic inflammatory manifestations and hematologic symptoms. To date, patients respond poorly to immune suppressive drugs, except high-dose glucocorticoids, and no treatment guidelines have been established. Given the high mortality rate, VEXAS syndrome needs to be taken seriously by physicians in all specialties. This article aims to describe the key features, pathogenesis, and clinical manifestations of VEXAS syndrome to better understand the targeted treatment and improve the prognosis of VEXAS syndrome.

VEXAS Syndrome-A Review of Pathophysiology, Presentation, and Prognosis

ABSTRACT

VEXAS ( V acuoles, E 1 enzyme, X -linked, A utoinflammatory, S omatic) syndrome is a newly identified disease caused by somatic mutations in the UBA1 gene resulting in refractory autoinflammatory features, frequently accompanied by cytopenias. Although the prevalence of this syndrome is yet unknown, understanding the clinical phenotype can assist clinicians in prompt recognition of cases among patients with glucocorticoid-responsive but immunosuppressive-resistant inflammatory symptoms. The pathophysiology, clinical presentation, diagnostic methods, treatment, and prognosis of VEXAS are herein reviewed.

Early activation of inflammatory pathways in UBA1-mutated hematopoietic stem and progenitor cells in VEXAS

VEXAS (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic) syndrome is a pleiotropic, severe autoinflammatory disease caused by somatic mutations in the ubiquitin-like modifier activating enzyme 1 (UBA1) gene. To elucidate VEXAS pathophysiology, we performed transcriptome sequencing of single bone marrow mononuclear cells and hematopoietic stem and progenitor cells (HSPCs) from VEXAS patients. HSPCs are biased toward myeloid (granulocytic) differentiation, and against lymphoid differentiation in VEXAS. Activation of multiple inflammatory pathways (interferons and tumor necrosis factor alpha) occurs ontogenically early in primitive hematopoietic cells and particularly in the myeloid lineage in VEXAS, and inflammation is prominent in UBA1-mutated cells. Dysregulation in protein degradation likely leads to higher stress response in VEXAS HSPCs, which positively correlates with inflammation. TCR usage is restricted and there are increased cytotoxicity and IFN-γ signaling in T cells. In VEXAS syndrome, both aberrant inflammation and myeloid predominance appear intrinsic to hematopoietic stem cells mutated in UBA1.

Biallelic structural variations within FGF12 detected by long-read sequencing in epilepsy

We discovered biallelic intragenic structural variations (SVs) in FGF12 by applying long-read whole genome sequencing to an exome-negative patient with developmental and epileptic encephalopathy (DEE). We also found another DEE patient carrying a biallelic (homozygous) single-nucleotide variant (SNV) in FGF12 that was detected by exome sequencing. FGF12 heterozygous recurrent missense variants with gain-of-function or heterozygous entire duplication of FGF12 are known causes of epilepsy, but biallelic SNVs/SVs have never been described. FGF12 encodes intracellular proteins interacting with the C-terminal domain of the alpha subunit of voltage-gated sodium channels 1.2, 1.5, and 1.6, promoting excitability by delaying fast inactivation of the channels. To validate the molecular pathomechanisms of these biallelic FGF12 SVs/SNV, highly sensitive gene expression analyses using lymphoblastoid cells from the patient with biallelic SVs, structural considerations, and Drosophila in vivo functional analysis of the SNV were performed, confirming loss-of-function. Our study highlights the importance of small SVs in Mendelian disorders, which may be overlooked by exome sequencing but can be detected efficiently by long-read whole genome sequencing, providing new insights into the pathomechanisms of human diseases.

VEXAS syndrome: Current clinical, diagnostic and treatment approaches

VEXAS syndrome, is a hemato-inflammatory chronic disease characterized with predominantly rheumatic and hematologic systemic involvement. It was first described in 2020 by a group of researchers in the United States. VEXAS syndrome is a rare condition that primarily affects adult males and is caused by a mutation in the UBA1 gene located on the X chromosome. Its pathogenesis is related to the somatic mutation affecting methionine-41 (p.Met41) in UBA1, the major E1 enzyme that initiates ubiquitylation. Mutant gene lead to decreased ubiquitination and activated innate immune pathways and systemic inflammation occur. The specific mechanism by which the UBA1 mutation leads to the clinical features of VEXAS syndrome is not yet fully understood. VEXAS is a newly define adult-onset inflammatory syndrome manifested with treatment-refractory fevers, arthritis, chondritis, vasculitis, cytopenias, typical vacuoles in hematopetic precursor cells, neutrophilic cutaneous and pulmonary inflammation. Diagnosing VEXAS syndrome can be challenging due to its rarity and the overlap of symptoms with other inflammatory conditions. Genetic testing to identify the UBA1 gene mutation is essential for definitive diagnosis. Currently, there is no known cure for VEXAS syndrome, and treatment mainly focuses on managing the symptoms. This may involve the use of anti-inflammatory medications, immunosuppressive drugs, and supportive therapies tailored to the individual patient's needs. Due to the recent discovery of VEXAS syndrome, ongoing research is being conducted to better understand its pathogenesis, clinical features, and potential treatment options. In this review article, the clinical, diagnostic and treatment approaches of VEXAS syndrome were evaluated in the light of the latest literature data.

Progress and challenges in the use of blood biomarkers in relapsing polychondritis

Relapsing polychondritis (RP) is a rare inflammatory disease with significant individual heterogeneity that involves systemic organs. The diagnosis of RP mainly depends on the clinical manifestations; currently, there are no molecular biomarkers routinely evaluated in clinical practice. Biomarkers have diagnostic or monitoring values and can predict response to treatment or the disease course. Over the years, many biomarkers have been proposed to facilitate diagnosis and prognosis. Unfortunately, ideal biomarkers to diagnose RP have not yet been discovered. Most of the molecular biomarkers in RP are immunological biomarkers, with autoantibodies and proteins related to cartilage damage in the blood being the most common. Alterations in some genes (HLA typing and UBA1 somatic mutation) were detected in patients with RP, which could serve as a potential biomarker for the diagnosis of RP. Moreover, proinflammatory cytokines and lymphocyte levels, and certain laboratory tests, have certain values of RP diagnosis and disease activity assessment but lack specificity and sensitivity. This review describes the different types of biomarkers and their clinical correlation with respect to the diagnosis of RP and disease activity. Research on biomarkers and disease pathology is ongoing to identify the ideal biomarkers that are sensitive and specific for RP.

Pulmonary manifestations in VEXAS (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic) syndrome: a systematic review

BACKGROUND

VEXAS (vacuoles, E1 enzyme, X-linked, auto-inflammatory, somatic) syndrome is a newly described auto-inflammatory disease. Many cases feature pulmonary infiltrates or respiratory failure. This systematic review aimed to summarize respiratory manifestations in VEXAS syndrome described to date.

METHODS

Databases were searched for articles discussing VEXAS syndrome until May 2022. The research question was: What are the pulmonary manifestations in patients with VEXAS syndrome? The search was restricted to English language and those discussing clinical presentation of disease. Information on basic demographics, type and prevalence of pulmonary manifestations, co-existing disease associations and author conclusions on pulmonary involvement were extracted. The protocol was registered on the PROSPERO register of systematic reviews.

RESULTS

Initially, 219 articles were retrieved with 36 ultimately included (all case reports or series). A total of 269 patients with VEXAS were included, 98.6% male, mean age 66.8 years at disease onset. The most frequently described pulmonary manifestation was infiltrates (43.1%; n = 116), followed by pleural effusion (7.4%; n = 20) and idiopathic interstitial pneumonia (3.3%; n = 9). Other pulmonary manifestations were: nonspecific interstitial pneumonia (n = 1), bronchiolitis obliterans (n = 3), pulmonary vasculitis (n = 6), bronchiectasis (n = 1), alveolar haemorrhage (n = 1), pulmonary embolism (n = 4), bronchial stenosis (n = 1), and alveolitis (n = 1). Several patients had one or more co-existing autoimmune/inflammatory condition. It was not reported which patients had particular pulmonary manifestations.

CONCLUSION

This is the first systematic review undertaken in VEXAS patients. Our results demonstrate that pulmonary involvement is common in this patient group. It is unclear if respiratory manifestations are part of the primary disease or a co-existing condition. Larger epidemiological analyses will aid further characterisation of pulmonary involvement and disease management.

Somatic mosaicism in inborn errors of immunity: Current knowledge, challenges, and future perspectives

Inborn errors of immunity (IEI) are a diverse group of monogenic disorders of the immune system due to germline variants in genes important for the immune response. Over the past decade there has been increasing recognition that acquired somatic variants present in a subset of cells can also lead to immune disorders or 'phenocopies' of IEI. Discovery of somatic mosaicism causing IEI has largely arisen from investigation of seemingly sporadic cases of IEI with predominant symptoms of autoinflammation and/or autoimmunity in which germline disease-causing variants are not detected. Disease-causing somatic mosaicism has been identified in genes that also cause germline IEI, such as FAS, and in genes without significant corresponding germline disease, such as UBA1 and TLR8. There are challenges in detecting low-level somatic variants, and it is likely that the extent of the somatic mosaicism causing IEI is largely uncharted. Here we review the field of somatic mosaicism leading to IEI and discuss challenges and methods for somatic variant detection, including diagnostic approaches for molecular diagnoses of patients.

[Autoinflammatory syndromes]

The concept of autoinflammation includes a heterogeneous group of monogenic and polygenic diseases. These are characterized by excessive activation of the innate immune system without antigen-specific T cells or autoantibodies. The diseases are characterized by periodic episodes of fever and increased inflammation parameters. Monogenic diseases include familial Mediterranean fever (FMF) and the newly described VEXAS (vacuoles, E1 enzyme, X‑linked, autoinflammatory, somatic) syndrome. Heterogeneous diseases include adult-onset Still's disease and Schnitzler syndrome. Treatment is aimed at preventing the excessive inflammatory reaction in order to avoid long-term damage, such as amyloid A (AA) amyloidosis.

Autoimmune manifestations in VEXAS: Opportunities for integration and pitfalls to interpretation

VEXAS (Vacuoles, E1 enzyme, X-linked, Autoinflammatory, Somatic) is a novel entity manifesting with a multiplicity of clinical features. Somatic mutations of the UBA1 gene in hematopoietic stem cells constitute the genetic basis of VEXAS. As an X-linked disorder, most cases occur in men, classically developing symptoms during the fifth to sixth decade of life. Considering its multidisciplinary nature involving numerous branches of internal medicine, VEXAS has elicited a wide medical interest and several medical conditions have been associated with this disease. Even so, its recognition in everyday clinical practice is not necessarily straightforward. Close collaboration between different medical specialists is mandatory. Patients with VEXAS may manifest a range of features from manageable cytopenias to disabling and life-threatening autoimmune phenomena with limited responses to therapy, with the potential for progression to hematological malignancies. Diagnostic and treatment guidelines are exploratory and include a range of rheumatological and supportive care treatments. Allogeneic hematopoietic stem cell transplantation is potentially curative, but its risks are significant and its position in the treatment algorithm is yet to be defined. Herein, we present the variegated manifestations of VEXAS, provide practice criteria for diagnostic testing of UBA1, and discuss potential treatment options, including allogeneic hematopoietic stem cell transplantation, current evidence, and future directions.

Cutaneous involvement in VEXAS syndrome: clinical and histopathologic findings

BACKGROUND

VEXAS (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic) syndrome is an autoinflammatory disease with frequent cutaneous manifestations.

METHODS

We conducted a retrospective study of all patients with genetically confirmed VEXAS syndrome seen at our institution. Available clinical photographs and skin biopsy slides were reviewed.

RESULTS

Cutaneous manifestations developed in 22/25 (88%) patients with VEXAS syndrome. From this group, 10/22 (45%) developed skin involvement before or at the time of other clinical features of VEXAS. Twenty distinct dermatologic presentations of VEXAS from 14 patients were reviewed, and histopathologic patterns were classified as follows: neutrophilic urticarial dermatosis (n = 5, 25%), leukocytoclastic/urticarial vasculitis (n = 4, 20%), urticarial tissue reaction (n = 4, 20%), neutrophilic dermatosis (n = 3, 15%), neutrophilic panniculitis (n = 2, 10%), and nonspecific chronic septal panniculitis (n = 2, 10%). Common systemic findings included macrocytic anemia (96%), fever (88%), thrombocytopenia (76%), weight loss (76%), ocular inflammation (64%), pulmonary infiltrates (56%), deep venous thrombosis or pulmonary embolism (52%), and inflammatory arthritis (52%).

CONCLUSIONS

Cutaneous involvement is a common feature of VEXAS syndrome, and histopathologic findings exist on a spectrum of neutrophilic inflammatory dermatoses.

Novel causative variants of VEXAS in UBA1 detected through whole genome transcriptome sequencing in a large cohort of hematological malignancies

UBA1 is an X-linked gene and encodes an ubiquitin-activating enzyme. Three somatic mutations altering the alternative start codon (M41) in UBA1 in hematopoietic precursor cells have recently been described, resulting in a syndrome of severe inflammation, cytopenias, and the presence of intracellular vacuoles in hematopoietic precursors - termed VEXAS syndrome, a predominantly male disease. Here we present a patient with clinical features of VEXAS who harbored two novel somatic variants in UBA1 (I894S and N606I). To better understand the clinical relevance and biological consequences of non-M41 (UBA1^non-M41) variants, we analyzed the whole genome and transcriptome data of 4168 patients with hematological malignancies and detected an additional 16 UBA1^non-M41 putative somatic variants with a clear sex-bias in patients with myeloid malignancies. Patients diagnosed with myeloid malignancies carrying UBA1^non-M41 putative somatic variants either had vacuoles or immunodysregulatory symptoms. Analysis of the transcriptome confirmed neutrophil activation in VEXAS patients compared to healthy controls but did not result in a specific transcriptomic signature of UBA1^M41 patients in comparison with MDS patients. In summary, we have described multiple putative novel UBA1^non-M41 variants in patients with various hematological malignancies expanding the genomic spectrum of VEXAS syndrome.