A case of VEXAS with microcytic anemia: don't be mislead by an associated condition!

VEXAS syndrome encompasses a wide range of rheumatological and hematological manifestations, which often features myelodysplastic syndrome accompanied by either macrocytic anemia or macrocytosis.

A 61-year-old Sicilian male was referred for a microcytic anemia associated with skin lesions, recurrent fever, involuntary weight loss, recurrent superficial venous thrombosis, migratory polyarthritis and a lung nodule. A hemoglobin electrophoresis uncovered a minor beta-thalassemia contributing to the anemia in addition to the chronic inflammation and vitamin B9/B12 deficiencies. A bone marrow aspiration demonstrated the presence of vacuoles in erythroid and myeloid precursors, as well as dysplasia in all three lineages. This led us to consider VEXAS syndrome which was confirmed by the presence of UBA1 mutation type p.M41T. Low-dose steroids and sarilumab (200 mg every 3 weeks) therapy led to a transient partial remission.

The pivotal insight from this observation centers around the microcytic characteristic of the anemia, with the confounding factor being minor thalassemia, whereas the type of anemia typically associated with VEXAS is macrocytic. This finding may be of particular relevance to patients from regions with endemic thalassemia. Consequently, the presence of microcytic anemia should not hinder clinicians from considering VEXAS syndrome in the appropriate clinical context.