Remnants of chylomicron and very low density lipoprotein impair endothelium-dependent vasorelaxation

Given the multiple impairments in host defense that occur during HIV infection, patients with AIDS are at risk for a variety of pleural infections and neoplasms. Of infectious causes, bacterial parapneumonic effusions and empyemas and tuberculous pleurisy occur more frequently than effusions caused by P. carinii. In each case, therapy is directed at eradication of the causative organisms. In the setting of systemic Kaposi's sarcoma, pleural involvement is common, although diagnosis is difficult and therapeutic options are limited. Pleural effusions caused by non-Hodgkin's lymphoma often occur in the setting of pulmonary parenchymal disease and can be diagnosed cytologically. The recently described entity of primary effusion lymphoma occurs in the absence of solid-organ involvement. The development of a spontaneous pneumothorax in a HIV-infected individual should prompt a search for P. carinii infection. Although these pneumothoraces often recur and are difficult to manage, recent series suggest that surgical approaches to bronchopleural fistulas are reasonable in selected patients.