Can VEXAS (VEXAS syndrome) syndrome show colonic inflammation on MRI (Magnetic Resonance Imaging)?

VEXAS Syndrome and Colonic Inflammation on MRI

VEXAS syndrome can potentially show colonic inflammation on MRI, but this is not a characteristic or well-documented feature of the disease, as VEXAS is primarily a systemic autoinflammatory condition affecting multiple organ systems with predominant hematologic and rheumatologic manifestations.

Understanding VEXAS Syndrome

VEXAS (Vacuoles, E1 enzyme, X-linked, Autoinflammatory, Somatic) syndrome is a recently described adult-onset monogenic autoinflammatory disease caused by somatic mutations in the UBA1 gene 1. It primarily affects older adults, particularly males, and presents with:

• Systemic inflammation
• Hematological abnormalities (myelodysplastic syndrome, cytopenias)
• Rheumatologic manifestations (arthritis, chondritis)
• Cutaneous manifestations (neutrophilic dermatoses)
• Pulmonary inflammation

Imaging Findings in VEXAS vs. Inflammatory Bowel Disease

While VEXAS can cause systemic inflammation affecting multiple organs 2, there is currently no specific evidence in the literature documenting colonic inflammation as a characteristic feature of VEXAS syndrome on MRI.

In contrast, MRI findings of colonic inflammation are well-documented in inflammatory bowel diseases like Crohn's disease and include:

• Bowel wall thickening (typically >3mm) 3
• Mural hyperenhancement on contrast-enhanced sequences 3
• Increased T2 signal intensity (mural edema) 3
• Restricted diffusion on diffusion-weighted imaging 3
• Perienteric inflammatory changes 3

Diagnostic Approach to Suspected Colonic Inflammation

If colonic inflammation is suspected in a patient with VEXAS syndrome:

1. Ileocolonoscopy with biopsies remains the gold standard for diagnosing colonic inflammation 4

2. MRI evaluation should include:

   • Bowel wall thickness assessment (>3mm is abnormal) 3
   • T2-weighted sequences to evaluate for mural edema 3
   • Contrast-enhanced sequences to assess for mural hyperenhancement 3
   • Diffusion-weighted imaging to detect active inflammation 3

3. Interpretation considerations:

   • MRI with only oral contrast will not detect or stage colonic inflammation as well as ileocolonoscopy 3
   • Segmental mural hyperenhancement can be caused by various conditions including vasculitis 3, which may be relevant in VEXAS

Clinical Implications

If colonic inflammation is detected on MRI in a patient with VEXAS syndrome, clinicians should consider:

• Whether the findings represent a direct manifestation of VEXAS or a concurrent inflammatory bowel disease
• The possibility of medication-induced colitis (e.g., from immunosuppressants used to treat VEXAS)
• The need for endoscopic evaluation to confirm findings and obtain tissue diagnosis

Important Caveats

• VEXAS is a recently described syndrome (first identified in 2020) 5, so its full spectrum of manifestations is still being characterized
• The absence of literature specifically documenting colonic inflammation in VEXAS does not definitively rule out this possibility
• MRI findings of colonic inflammation are nonspecific and can be seen in various inflammatory, infectious, and neoplastic conditions
• Patients with VEXAS may have comorbid conditions that could cause colonic inflammation

In summary, while MRI can detect colonic inflammation through specific imaging findings, there is currently insufficient evidence to establish colonic inflammation as a characteristic feature of VEXAS syndrome. Any colonic abnormalities detected on MRI in VEXAS patients should prompt further evaluation to determine their etiology.