Chronic-active Epstein-Barr virus infection (CAEBV) is a rare disease that can lead to pulmonary arterial hypertension (PAH). However, the treatment for CAEBV-associated PAH has not been established. We discuss a case of improved pulmonary hypertension after chemotherapy in a patient with CAEBV-associated PAH. A 44-year old man was admitted to our hospital because of an abnormal electrocardiogram and liver dysfunction detected by annual medical examination. Echocardiography showed a dilated right ventricle and an estimated right ventricular systolic pressure of 92 mmHg. Right heart catheterization revealed a mean pulmonary arterial pressure of 45 mmHg and pulmonary vascular resistance of 9.8 Wood units. Laboratory examination showed granular lymphocytes and 91% natural killer cells in lymphocyte subsets in peripheral blood. We diagnosed the patient as having CAEBV-associated PAH. After two cycles of chemotherapy without PAH-specific drugs, echocardiography showed improvement in the dilated right ventricle and an estimated right ventricular systolic pressure of 59 mmHg. Right heart catheterization revealed a mean pulmonary arterial pressure of 27 mmHg and pulmonary vascular resistance of 2.4 Wood units. Chemotherapy may improve pulmonary hypertension in patients with CAEBV-associated PAH.
Keywords: Natural killer cells; Pulmonary hypertension.