Recovery of Bone Marrow Function in VEXAS Syndrome-potential Role for Romiplostim

V EXAS (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic) syndrome is a recently reported late-onset hematoinflammatory disorder occurring predominantly in older men, due to acquired mutations in the X-linked UBA1 gene. 1 An emerging category of hematoinflammatory disorders are broadly defined as diseases caused by somatic mutations restricted to the blood, but results in systemic inflammation with multiorgan involvement and are associated with abnormal and/or premalignant bone marrow (BM) changes. 2 The inflammatory manifestations are driven in part by activation of the NLRP3 inflammasome and release of proinflammatory cytokines such as interleukin (IL)-1 β , IL-18, and IL-6. 3 The hematological manifestations include vacuoles in erythroid and myeloid precursors, macrocytosis, and multilineage cytopenias. Most patients are diagnosed with clonal cytopenia of unknown significance, with 31%–50% of cases also fulfilling diagnostic criteria for myelodysplastic syndrome (MDS). 4,5 Typical inflammatory manifestations include fever, weight loss, skin lesions, lung disease, joint involvement, and inflammatory eye disease, while VEXAS can clinically mimic inflammatory syndromes such as Sweet’s syndrome (acute febrile neutrophilic dermatosis), relapsing poly-chondritis, and polyarteritis nodosa. 4,5 The best characterized and, to date, most common pathogenic variants lead to