Abstract
OBJECTIVES: VEXAS syndrome is a recently characterized hemato-inflammatory disorder caused by somatic mutations in the X-linked UBA1 gene in hematopoietic cells, which remains poorly characterized in Chinese populations. This study aims to address this gap. METHODS: We retrospectively analyzed 4512 consecutive patients with hematologic abnormalities at a Chinese academic hospital between June 2023 and July 2024, identifying 16 male VEXAS patients (median age 61.5 years, range 30-74). RESULTS: All patients presented with anemia and lymphopenia, with or without neutropenia and thrombocytopenia. Diagnoses included CCUS, MDS, MGUS, as well as novel phenotypes of primary myelofibrosis and a hemolysis-like disorder. Most patients (11/16, 69%) exhibited constitutional symptoms and typical autoinflammation-associated multiorgan involvement, including skin lesions, ear chondritis, pulmonary infiltration, and deep vein thrombosis, etc. Hypercellular bone marrow was commonly seen in core biopsies and 11 patients (68.8%) exhibited typical vacuoles in myeloid and erythroid progenitors. Canonical UBA1 pathogenic variants were detected in 81.3% (13/16) of patients, with p.M41V being the dominant mutation. Three infrequent variants were also identified: c.118-1G>C, p.S56P, and p.S621C. Corticosteroids and immunosuppressants commonly provided symptomatic relief, while variable hematologic responses were achieved with androgens and erythropoiesis-stimulating agents. CONCLUSIONS: As a relatively large cohort of VEXAS syndrome characterizing Chinese patients, our findings demonstrate that VEXAS should be considered in those with cytopenia, regardless of systemic symptoms or multiorgan involvement. Increased awareness among hematologists is critical to facilitate early diagnosis via UBA1 testing. This can prevent unnecessary diagnostic procedures and guide appropriate treatment, including consideration of pre-emptive stem cell transplantation.