Primary pulmonary hypertension associated with human immunodeficiency viral infection

Acquired immunodeficiency syndrome (AIDS) is associated with various cardiovascular disorders, such as impaired heart function; accumulation of fluid in the membrane surrounding the heart; cancer; and opportunistic infections. Four cases are described consisting of two patients with AIDS, and two patients with human immunodeficiency virus (HIV) infection. The patients developed high pressure (hypertension) in the pulmonary artery, the major blood vessel supplying the lungs, and were diagnosed as having primary pulmonary hypertension. This disorder is characterized by increased pulmonary arterial pressure resulting from structural abnormalities in the blood vessels due to some unknown cause. Two of the patients died, and the diagnosis of pulmonary hypertension was confirmed by autopsy. Primary pulmonary hypertension is associated with three pathologic characteristics: disease of the pulmonary arteries; recurrent blood clot formation in the pulmonary arteries; and obstruction of the pulmonary veins. Structural changes in the blood vessels include enlargement of the muscle layer, followed by cell overgrowth in the inner layer. There have been nine reports of HIV-infected patients with primary pulmonary hypertension. The mechanisms underlying the development of pulmonary hypertension associated with HIV infection are not clear, but may be related to a reaction of the lungs to HIV; the production of abnormal growth factors; or impaired function of the right heart ventricle due to opportunistic infection with Pneumocystis carinii. (Consumer Summary produced by Reliance Medical Information, Inc.)