Correction of hypercoagulability and amelioration of pulmonary arterial hypertension by chronic blood transfusion in an asplenic hemoglobin E/β-thalassemia patient

Chronic transfusion of packed red blood cells, in addition to other ongoing treatment with warfarin, acetyl salicylic acid, desferrioxamine, and other supportive measures, was given to a splenectomized hemoglobin E/β-thalassemia woman with pulmonary arterial hypertension (PHT). Serial measurements of plasma thrombin-antithrombin III complex (TAT) levels and right-sided cardiac catheterization were used to monitor changes after treatment. Reduction of plasma TAT levels from 7.5 to 3.8 μg/L (normal, 3 ± 2.4 μg/L), pulmonary vascular resistance (PVR) from 553.8 to 238.6 dyne.sec.cm^-5 (normal, 67 ± 30 dyne.sec.cm^-5), and mean pulmonary arterial pressure from 51 to 32 mm Hg (normal, 9 to 19 mm Hg) occurred in tandem. Normalization of blood hypercoagulability as reflected in plasma TAT level by chronic blood transfusion was the likely basis for improvement of increased PVR, being secondary to thrombotic pulmonary arteriopathy and subsequently PHT.