The First Reported Case of VEXAS Syndrome in Lebanon: Efficacy of Azacitidine as a Therapeutic Option-Case Report.

Background: Vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic (VEXAS) syndrome is a rare, adult-onset autoinflammatory disease that has only been described since late 2020. Given the rarity of the disease and the absence of established treatment guidelines, management remains challenging and largely based on clinical experience and case reports. Case presentation: This paper reports the first documented case of VEXAS syndrome in Lebanon. A 73-year-old man presented with fever, severe asthenia, erythematous skin lesions, and anemia, initially diagnosed as giant cell arteritis. Following a diagnosis of VEXAS syndrome, he was treated with corticosteroids and methotrexate but developed refractory anemia and required erythropoietin therapy. Tocilizumab was introduced to manage inflammation, but the patient's condition remained challenging due to corticosteroid dependence and myelodysplastic syndrome (MDS). Given the patient's comorbidities and intermediate-risk MDS, azacitidine was initiated as a therapeutic option. Despite initial neutropenia and infections, adjustments to the azacitidine regimen led to significant clinical and hematologic improvements. The patient achieved complete remission, became transfusion-independent, and maintained stable hemoglobin levels. Conclusion: This case highlights the efficacy of azacitidine in managing VEXAS syndrome with MDS, particularly among patients ineligible for hematopoietic stem cell transplantation, offering a potential pathway to sustained remission and reduced corticosteroid dependence.