A rare cause of Pulmonary Hypertension - Protein S Deficiency

Protein S deficiency is a rare form of inherited thrombotic disorder. This is a case report of protein S deficiency presenting as chronic thromboembolic pulmonary hypertension. Middle aged male patient presented with features of pulmonary hypertension and right heart failure with past history of Mesenteric Venous Thrombosis (MVT) few years back. Investigations revealed mosaic pattern of attenuation in CT pulmonary angiogram and Protein S deficiency. Incidentally this patient belongs to Bombay blood group. Protein S is a vitamin K dependent plasma glycoprotein. It facilitates the anticoagulant activity of activated protein C. Protein S deficiency can cause both venous and arterial thrombosis. Among unselected outpatients presenting with venous thromboembolism (VTE) 2 to 3 may have low levels of protein S. Management of protein S deficiency includes lifelong anticoagulation.