Summarized by: Sophie GEORGIN LAVIALLE
Reference: Bixio R, The role of 18FDG–PET imaging in VEXAS syndrome: a multicentric case series and a systematic review of the literature, Internal and Emergency Medicine, 2024 Nov;19(8):2331-2345.
PubMed link: https://pubmed.ncbi.nlm.nih.gov/39251478/

Summary:
Introduction:
VEXAS syndrome (Vacuoles, E1 enzyme, X-linked, Autoinflammatory, Somatic) is an autoinflammatory disease associated with somatic mutations in the UBA1 gene. Patients typically present with systemic symptoms (fever, weight loss, skin rashes, lung involvement, chondritis, vasculitis, etc.), macrocytic anemia, and often a myelodysplastic syndrome. Given the clinical heterogeneity and lack of established diagnostic criteria, 18F-fluorodeoxyglucose PET (18FDG–PET) imaging may help with diagnosis and disease monitoring.
Patients and Methods:
This article reports a multicenter Italian case series of 8 patients, combined with a systematic review of the literature, totaling 35 cases.
Results:
All patients were male, with a median age of 70 years. The most common mutations were Met41Thr, Met41Val, and Met41Leu. The main indication for PET imaging was to investigate inflammatory foci or rule out malignancy.
PET scan analysis showed a high prevalence of bone marrow hypermetabolism (77%), followed by lymph nodes (35%), lungs (29%), spleen, large vessels, and cartilage (23% and 20% respectively). In six cases, PET imaging performed before diagnosis already showed increased bone marrow uptake. In some patients, follow-up PET scans after treatment (glucocorticoids or JAK inhibitors) revealed a reduction or even disappearance of hypermetabolic foci.
The authors also provide a summary diagram of the main lesions (see next page).
Conclusion:
Although no specific uptake pattern was identified, bone marrow hypermetabolism may precede clinical manifestations, suggesting a potential role for PET imaging in the early diagnosis and monitoring of VEXAS syndrome. Additionally, PET scans can assist in excluding differential diagnoses, especially malignancies and infections.