VEXAS syndrome – Diagnostics – Overview of Information and Clinical Research

Understanding how VEXAS syndrome is diagnosed can help patients and healthcare providers recognize this rare condition earlier. Diagnosing VEXAS requires a combination of clinical observation, laboratory testing, and genetic analysis to confirm the presence of a UBA1 gene mutation that sets this syndrome apart from other inflammatory diseases.

Introduction: When to Seek Diagnostic Evaluation

VEXAS syndrome is a rare condition that often hides behind symptoms that look like many other diseases. Because of this, knowing when to seek medical attention and diagnostic testing is crucial. Most people who develop VEXAS syndrome are older adults, typically over the age of 50, and the vast majority are men. However, the condition can also occur in women, particularly those with certain chromosomal changes.^[1]

You should consider seeking diagnostic evaluation if you experience persistent, unexplained inflammation that doesn’t respond well to typical treatments. This might include recurring fevers that come and go without a clear cause, ongoing joint pain and swelling, skin rashes that appear suddenly and persist, or unexplained fatigue that affects your daily life. Many people with VEXAS syndrome also develop problems with their blood, such as anemia (a shortage of red blood cells that makes you feel tired and weak), which shows up in routine blood work.^[2]

Healthcare providers should especially consider VEXAS syndrome testing when a patient has been diagnosed with conditions like relapsing polychondritis (inflammation of cartilage, especially in the ears and nose), polyarteritis nodosa (inflammation of blood vessels), Sweet syndrome (a type of skin condition with painful bumps), or myelodysplastic syndrome (a blood disorder where the bone marrow doesn’t make enough healthy blood cells). When these conditions don’t respond well to standard treatments, or when multiple inflammatory problems appear together, VEXAS syndrome becomes a possibility worth investigating.^[3]

⚠️ Important

VEXAS syndrome is often misdiagnosed or takes years to identify because its symptoms overlap with many other conditions. If you have persistent inflammation, blood abnormalities, or multiple inflammatory conditions that don’t respond to treatment, discussing VEXAS syndrome testing with your doctor may be worthwhile, especially if you’re a man over 50.

The challenge with VEXAS syndrome is that it can look different from person to person. Some patients might have severe lung problems with coughing and shortness of breath, while others might have painful skin lesions or swollen, inflamed cartilage in their ears and nose. Blood clots can occur, and some people develop eye redness and irritation. Because the symptoms vary so much and can affect so many different parts of the body, patients often see multiple specialists—rheumatologists, hematologists, dermatologists, and others—before anyone suspects VEXAS syndrome.^[2]

Classic Diagnostic Methods

Genetic Testing: The Definitive Diagnosis

The only way to confirm VEXAS syndrome with certainty is through genetic testing that looks for mutations in the UBA1 gene. This gene is located on the X chromosome and is responsible for making an enzyme called E1 ubiquitin-activating enzyme. In people with VEXAS syndrome, this gene doesn’t work properly due to a mutation that typically affects a specific spot called methionine-41, or p.Met41. When this mutation occurs, cells cannot properly clean up damaged proteins, which leads to the buildup of waste inside cells and triggers the immune system to attack the body.^[1]^[3]

For genetic testing, healthcare providers take either a blood sample or a bone marrow sample and send it to a specialized laboratory. The lab analyzes the DNA specifically looking for changes in the UBA1 gene. The most common mutations found are p.Met41Thr, p.Met41Val, and p.Met41Leu, though researchers have discovered additional variations as they continue to study this condition. This test is essential because VEXAS syndrome can only be definitively diagnosed when this specific genetic mutation is present.^[8]^[11]

It’s important to understand that this mutation is somatic, meaning it happens randomly during a person’s lifetime and is not inherited from parents. This also means you cannot pass it on to your children. The mutation occurs in certain blood-forming cells in the bone marrow, which is why it primarily affects blood cells and immune cells rather than all cells in the body.^[4]

Bone Marrow Examination

Another critical diagnostic tool is bone marrow examination, which involves taking a small sample of bone marrow tissue, usually from the hip bone. This procedure, called a bone marrow biopsy, allows doctors to look at the cells under a microscope to identify specific abnormalities that occur in VEXAS syndrome. One of the hallmark features doctors look for is the presence of vacuoles—rounded, empty spaces within certain bone marrow cells. These vacuoles in the hematopoietic precursor cells (cells that develop into blood cells) are characteristic of VEXAS syndrome and actually give the condition its name, as the “V” in VEXAS stands for “vacuoles.”^[1]^[11]

During the bone marrow examination, doctors also check for signs of myelodysplastic syndrome, a blood disorder that frequently occurs alongside VEXAS syndrome. Studies have found that around 40% of people with VEXAS syndrome also have myelodysplastic syndrome, where the bone marrow fails to produce healthy blood cells properly. This connection is why both hematologists and rheumatologists often work together to diagnose and manage VEXAS syndrome.^[12]

Blood Tests and Laboratory Work

While genetic testing is the definitive diagnostic tool, various blood tests provide important clues that help doctors suspect VEXAS syndrome in the first place. Complete blood count tests often reveal anemia, where red blood cells are both reduced in number and unusually large (called macrocytic anemia). Many patients also show low platelet counts, a condition called thrombocytopenia, which can increase the risk of bleeding problems.^[2]^[4]

Inflammatory markers in the blood are typically elevated in VEXAS syndrome. Tests measuring inflammation levels can show that the body is experiencing significant immune system activation, though these results alone don’t point specifically to VEXAS syndrome—they simply indicate that abnormal inflammation is occurring. White blood cell counts may also be abnormal, sometimes rising to levels 10 times higher than normal.^[5]

Imaging Studies

Various imaging tests help doctors assess how VEXAS syndrome is affecting different organs and tissues throughout the body. Chest CT scans can reveal lung problems such as infiltrates, pleural effusion (fluid around the lungs), or signs of inflammation in the airways. These imaging studies are particularly important because lung involvement is common in VEXAS syndrome and can be serious if not detected and managed properly.^[11]

Other imaging techniques might be used depending on symptoms. For instance, if a patient has joint pain and swelling, X-rays or ultrasound of the affected joints can help determine the extent of inflammation. If blood vessel inflammation is suspected, specialized imaging can visualize the arteries and veins to check for vasculitis (inflammation of blood vessels).^[3]

Skin and Tissue Biopsies

When patients develop skin rashes or lesions, doctors may perform a skin biopsy to examine the tissue under a microscope. This can reveal characteristic patterns of inflammation, such as neutrophilic dermatosis (a type of skin inflammation involving a particular kind of white blood cell). These findings, combined with other test results, help build the case for VEXAS syndrome, especially when the skin problems don’t respond to typical treatments.^[3]

Similarly, if inflammation affects cartilage in the ears or nose, biopsies of these tissues can show patterns consistent with VEXAS syndrome, particularly when other diagnostic features are present.^[11]

Distinguishing VEXAS from Other Conditions

One of the biggest challenges in diagnosing VEXAS syndrome is that it can look remarkably similar to other inflammatory and autoimmune conditions. The symptoms overlap significantly with diseases like rheumatoid arthritis, lupus, various types of vasculitis, and blood disorders. This is why VEXAS syndrome has often been misdiagnosed for years before the correct identification is made.^[3]^[9]

The key to distinguishing VEXAS syndrome is the presence of the UBA1 gene mutation combined with characteristic findings like vacuoles in bone marrow cells. No other condition has this specific combination. However, because genetic testing for UBA1 mutations has only been available since 2020, when the syndrome was first described, many people who have VEXAS syndrome may still be living with an incorrect diagnosis or no diagnosis at all.^[3]

⚠️ Important

VEXAS syndrome can be challenging to diagnose because symptoms vary widely and overlap with many other conditions. The syndrome may be hard to identify even after extensive testing, which is why a combination of clinical findings, blood work, bone marrow examination, and genetic testing is necessary to reach an accurate diagnosis.

Diagnostics for Clinical Trial Qualification

Clinical trials investigating potential treatments for VEXAS syndrome have specific diagnostic criteria that patients must meet to participate. Understanding these requirements can help patients and their doctors determine if clinical trial participation might be an option.^[7]

Confirmed Genetic Diagnosis

The fundamental requirement for entering any VEXAS syndrome clinical trial is confirmation of a UBA1 gene mutation through genetic testing. Trials typically require documentation showing that genetic testing was performed by a certified laboratory and that a pathogenic (disease-causing) variant in the UBA1 gene was identified. This ensures that all participants truly have VEXAS syndrome rather than a condition with similar symptoms.^[8]

Some clinical trials may have specific requirements about which UBA1 mutations qualify for enrollment. For example, certain trials might focus only on patients with the most common mutations (p.Met41Thr, p.Met41Val, or p.Met41Leu), while others might include patients with any documented UBA1 mutation. Researchers are still learning about whether different mutations lead to different disease patterns, which is why some trials want to study specific mutation types.^[10]

Baseline Assessment of Disease Activity

Clinical trials need to measure how active a patient’s VEXAS syndrome is before treatment begins so they can later determine if the experimental therapy is working. This means patients must undergo comprehensive baseline testing before enrollment. This typically includes detailed blood work to document levels of inflammation, anemia, platelet counts, and white blood cell counts. These baseline measurements establish a starting point for comparison.^[12]

Researchers also document which organs and systems are affected by VEXAS syndrome at the time of enrollment. This might involve chest imaging to assess lung involvement, assessment of skin lesions, documentation of joint inflammation, and examination of cartilage inflammation in the ears and nose. The more detailed this baseline picture, the better researchers can understand whether the treatment being studied is helping.^[11]

Bone Marrow Status

Many clinical trials require a recent bone marrow biopsy to document the extent of bone marrow involvement and to check for the presence of vacuoles in bone marrow cells. This is particularly important for trials testing medications that affect blood cell production or bone marrow function. If a patient has developed myelodysplastic syndrome alongside VEXAS syndrome, this needs to be documented, as it may influence which trials they’re eligible for and which treatments might be most appropriate.^[7]

Some trials specifically focus on patients who have both VEXAS syndrome and myelodysplastic syndrome, as these patients may need different treatment approaches. Other trials might exclude patients with certain blood cancers or severe bone marrow failure to focus on a more specific patient population.^[12]

Previous Treatment History

Clinical trials typically want detailed information about what treatments patients have already tried and how well they worked. This includes documentation of steroid use (such as prednisone), immunosuppressive medications, and any biologic drugs that were tried. Knowing which treatments have failed helps researchers understand whether their experimental therapy might work through a different mechanism.^[7]

Some trials specifically seek patients whose VEXAS syndrome hasn’t responded well to standard treatments—this is called “treatment-refractory” disease. These patients are often eager to try new approaches since conventional therapies haven’t provided adequate relief. Other trials might focus on newly diagnosed patients who haven’t yet tried many treatments, allowing researchers to study the experimental therapy without the confounding effects of multiple prior medications.^[3]

Organ Function Testing

Most clinical trials require documentation that major organs are functioning well enough to handle the experimental treatment. This typically includes tests of kidney function, liver function, and heart function. For instance, blood tests measuring creatinine levels show how well the kidneys are working, while liver enzyme tests reveal liver health. Some medications being studied might put stress on these organs, so ensuring they’re functioning adequately before starting treatment is a safety measure.^[8]

Lung function tests might also be required, especially for trials testing drugs that could affect the respiratory system. These tests measure how much air you can breathe in and out and how efficiently your lungs transfer oxygen to your blood. Given that many people with VEXAS syndrome have lung involvement, these baseline measurements are particularly important.^[11]

Exclusion Criteria

Clinical trials also have specific situations that prevent enrollment, called exclusion criteria. These are designed to protect patient safety and ensure the trial results are scientifically valid. Common exclusions include active infections, certain other medical conditions, pregnancy or breastfeeding, and recent participation in other clinical trials. Some trials exclude patients who are currently taking certain medications that might interfere with the experimental treatment.^[7]

Age restrictions may apply to some trials, though VEXAS syndrome primarily affects older adults, so age limits tend to be flexible. However, patients need to be healthy enough overall to participate in the study, attend required visits, and undergo necessary testing throughout the trial period.^[17]

Prognosis and Survival Rate

Prognosis

VEXAS syndrome is a serious condition that can be life-threatening if not properly treated. The course of the disease varies from person to person, but several factors influence how the syndrome progresses. The presence of certain blood disorders, particularly myelodysplastic syndrome, tends to indicate a more serious prognosis. Patients who develop severe bone marrow failure or progress to blood cancers like leukemia face greater challenges. The extent of organ involvement also matters—those with severe lung problems, widespread inflammation affecting multiple organs, or complications like blood clots typically have more difficult disease courses.^[5]

How well VEXAS syndrome responds to treatment is another key factor in prognosis. While many patients initially respond to high-dose steroids, long-term steroid use causes serious side effects including bone thinning, weight gain, high blood sugar, and increased infection risk. Some patients don’t respond adequately even to steroids, which presents a major treatment challenge. The development of new treatment options, including medications like azacitidine, JAK inhibitors, and IL-6 inhibitors, has improved outcomes for some patients, though responses vary considerably. Bone marrow transplant, which may offer the possibility of long-term disease control or even cure for some patients, carries its own significant risks, especially in older adults who make up the majority of VEXAS patients.^[8]^[12]

Without treatment, VEXAS syndrome can lead to progressive organ damage, severe blood problems, and life-threatening complications. With appropriate treatment and close medical supervision, many patients can achieve better disease control and improved quality of life, though the syndrome remains a chronic condition requiring ongoing management.^[13]

Survival Rate

VEXAS syndrome has a high mortality rate, which underscores the seriousness of this condition. Research indicates that up to half of people diagnosed with VEXAS syndrome die within five years of diagnosis. This makes it one of the more dangerous autoinflammatory diseases, with a death rate that exceeds many other inflammatory conditions.^[5]^[15]

The high mortality rate is influenced by several factors. Complications from VEXAS syndrome itself—including severe inflammation, organ damage, blood clots, and bone marrow failure—contribute to deaths. Additionally, the treatments used to control the syndrome, particularly long-term high-dose steroids, can cause complications that affect survival. Infections are a particular concern, as both the disease and the immunosuppressive treatments used to manage it can increase vulnerability to serious infections. Some patients die from progression to blood cancers or from complications of myelodysplastic syndrome.^[5]

It’s important to note that VEXAS syndrome was only identified in 2020, so long-term survival data is still being collected. Earlier diagnosis and newer treatment approaches may improve survival rates over time. However, the current data emphasizes the importance of prompt diagnosis, aggressive treatment when appropriate, and close medical monitoring to manage this serious condition.^[3]

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