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

VEXAS-Defining UBA1 Somatic Variants in 245,368 Diverse Individuals in the NIH All Of Us Cohort

OBJECTIVE

Somatic variants in UBA1 cause VEXAS, a recently described, systemic autoinflammatory disease. Research on VEXAS has largely focused on highly symptomatic patients. We sought to determine the prevalence of canonical, VEXAS-associated somatic variants and their disease penetrance in a diverse, unselected population.

METHODS

We analyzed clinical-grade whole genome sequencing data from 245,368 participants in the All of Us Research Program. We compared persons carrying a canonical VEXAS-associated somatic variant to age, sex, and ancestry matched controls across the domains of diagnoses, medications, and laboratory values.

RESULTS

74 participants were identified who carry one VEXAS-defining somatic variant, UBA1 c.121A>C, p.Met41Leu. The variant allele fraction ranged from 4.5% to 33%. No other canonical VEXAS-associated variants were identified. Of the 74 carriers, 62 (84%) were women, 20 (27%) were African American, and 14 (19%) were American Admixed/Latino. There was no statistically significant association between case/control status and any VEXAS-associated diagnosis code, medication prescription, or laboratory value.

CONCLUSION

We report the largest cohort to date of persons with the VEXAS-associated p.Met41Leu somatic variant. This cohort differed substantially from reported cohorts of patients with clinical VEXAS, having a higher proportion of persons who were young, female, and of diverse ancestry. Variant allele fractions were lower than reported in clinical VEXAS cohorts, and bioinformatic analysis detected no clinical manifestations of VEXAS. Thus, the UBA1 p.Met41Leu somatic variant displayed incomplete penetrance for VEXAS. Further study is needed to determine the natural history of VEXAS-associated somatic variants in the predisease phase.

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.

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: 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.

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.