A case of VEXAS syndrome presenting as macrophage activation syndrome: from chronic inflammation to multi-organ failure

VEXAS (vacuoles, E1 enzyme, X-linked, auto-inflammatory, somatic) syndrome is a severe, progressive disease caused by a somatic mutation of the X-linked UBA1 gene encoding for the E1-ubiquitin-activating enzyme. MAS (macrophage activation syndrome) is a hyper-inflammatory syndrome characterized by a cytokine storm. This storm occurs more frequently in other auto- inflammatory syndromes, such as adult-onset Still’s disease (AOSD) and monogenic periodic fever, than in VEXAS syndrome