At European Alliance of Associations for Rheumatology (EULAR) in Barcelona, one of the sessions that generated a lot of discussion focused on a condition many patients may not have heard of yet:
VEXAS syndrome. Even for experienced advocates and clinicians, VEXAS is still relatively new, having been formally named only about three years ago. What makes it especially important for our community is that VEXAS can include a clear inflammatory arthritis component, placing it squarely within the
autoimmune and autoinflammatory arthritis disease space.
This session offered a deep dive into what VEXAS is, how it presents, and why it is reshaping how doctors think about inflammation, genetics, and rheumatic disease.
What is VEXAS syndrome?
VEXAS is an acronym that describes key features of the condition:
- V stands for vacuoles, which are abnormal structures seen in bone marrow cells
- E refers to the E1 enzyme, specifically mutations affecting the UBA1 gene
- X indicates that the mutation is X-linked, meaning it is located on the X chromosome
- A represents autoinflammatory disease
- S stands for somatic mutations, meaning the genetic change occurs during a person’s lifetime rather than being inherited
In simple terms, VEXAS syndrome is caused by an acquired genetic mutation in the bone marrow that leads to widespread inflammation throughout the body. Because the mutation is somatic, people are not born with it. It develops later in life, which is why VEXAS was only recently discovered despite decades of rheumatology research.
Who is most affected?
One of the striking features of VEXAS is who it tends to affect. According to data shared in the session, about 99 percent of diagnosed patients are men over the age of 50. While there are rare cases in women, the condition overwhelmingly affects older men due to its X-linked nature.
This demographic pattern is one reason VEXAS flew under the radar for so long. Many patients were previously diagnosed with other inflammatory or rheumatic diseases, blood disorders, or unexplained systemic inflammation before VEXAS was identified as a distinct condition.
Common symptoms and disease features
VEXAS syndrome does not affect just one system. It is a multisystem inflammatory condition, which makes it particularly challenging to diagnose. Some of the most common features discussed included:
- Skin involvement, seen in more than 80 percent of patients, including rashes, nodules, vasculitis, and hive-like lesions
- Constitutional symptoms, such as fevers, fatigue, night sweats, and weight loss, affecting roughly two thirds of patients
- Respiratory involvement, reported in over half of patients
- Musculoskeletal symptoms, including arthritis and muscle inflammation, present in nearly half of cases
- Eye inflammation, cartilage inflammation of the ears and nose, and other organ involvement
Importantly for the AiArthritis community, arthritis and muscle inflammation are recognized as key parts of the disease, reinforcing why VEXAS belongs in conversations about rheumatic and inflammatory arthritis conditions.
A disease at the crossroads of rheumatology and hematology
One of the most important takeaways from this session was that VEXAS challenges traditional boundaries between specialties. The disease originates in the bone marrow and involves blood cells, which places it firmly in the realm of hematology. At the same time, its inflammatory symptoms overlap with rheumatologic diseases like vasculitis, relapsing polychondritis, and inflammatory arthritis.
VEXAS is also closely linked to clonal hematopoiesis, a process where certain blood cell clones expand due to acquired mutations. This connection helps explain why VEXAS can be associated with serious infections over time and why some patients may develop blood-related complications or malignancies.
Why awareness of VEXAS matters
Because VEXAS is so new, many patients are still misdiagnosed or diagnosed late. People may spend years being treated for other inflammatory conditions without fully responding to therapy. Recognizing VEXAS as a possibility, especially in older men with unexplained systemic inflammation and arthritis, can change the diagnostic path and open doors to more appropriate management.
For patients, this highlights the importance of asking questions when symptoms do not fit neatly into one diagnosis or when treatments are not working as expected. For clinicians, it underscores the need to think beyond traditional categories and consider genetic and bone marrow driven inflammation.
Looking ahead
Research on VEXAS is evolving rapidly, with dozens of studies and references already emerging despite its recent discovery. As scientists learn more about how somatic mutations drive inflammation, VEXAS may help unlock insights into other inflammatory and rheumatic diseases as well.
For now, the key message is awareness. VEXAS syndrome is rare, complex, and newly recognized, but it has a real and meaningful connection to inflammatory arthritis. As knowledge grows, continued education and shared learning will be essential in improving diagnosis, treatment, and quality of life for those affected.
AiArthritis will continue to follow this research closely and translate new findings into clear, patient-focused information as the science advances.
Check out our
VEXAS page and learn more about
“Go With Us!” to Conferences.
