BACKGROUND Hyperimmunoglobulinemia E syndrome is a primary immunodeficiency disorder characterized by elevated IgE levels, recurrent infections, pruritic rash, and skeletal and dental abnormalities. Autosomal dominant, autosomal recessive, and sporadic forms have been described. Coronary artery aneurysms and analysis of central (TCMs) and effector (TEMs) memory T cells have not been previously reported with this syndrome. OBJECTIVE To describe a 30-year-old woman with hyperimmunoglobulinemia E syndrome who was found to have coronary artery aneurysms, deficiency in CD4+ TCMs, and expansion of CD4+ TEMs expressing CD45RA antigen (TEMRAs). METHODS The patient presented to the clinic after hospitalization for chest pain. Coronary angiogram performed during the hospitalization revealed aneurysms in multiple coronary arteries with thrombus formation. In addition, she had a history of recurrent pneumonia, staphylococcal skin abscesses, and a pruritic facial rash. An extensive immunologic evaluation was performed. RESULTS Immunologic studies revealed increased serum IgE levels (13,434 IU/dL), decreased proliferative responses to the soluble recall antigens tetanus toxoid and Candida albicans, and normal responses to mitogens. Analysis of lymphocyte subsets showed a deficiency of CD4+ TEMs and an increase in CD4+ TEMRAs. In addition, a decreased proportion and number of memory B cells and a deficiency in antibody response to pneumococcal antigens were observed. CONCLUSIONS Hyperimmunoglobulinemia E syndrome may be associated with coronary artery aneurysms and with deficiency in CD4+ TEMs and expansion of CD4+ TEMRAs. Comprehensive immunologic evaluation should be performed in patients with this syndrome.