Pulmonary complications of human immunodeficiency virus (HIV) infection are common causes of morbidity and mortality among patients with AIDS. Pneumocystis carinii pneumonia has been the most common index diagnosis of AIDS and is among the most frequent causes of death. Nonspecific interstitial pneumonitis (NIP), characterized by diffuse alveolar damage and macrophage or lymphocytic infiltration, or both, is a common cause of pulmonary disease in HIV-infected patients. NIP is identified in up to 32 percent of all episodes of HIV-related pneumonitis, but rarely causes respiratory failure. The etiology of NIP is not known.
Recently, anecdotal evidence and uncontrolled trials of corticosteroid therapy for P carinii pneumonia have given way to a growing consensus, based on several well-designed studies, that corticosteroids are beneficial as adjunctive therapy in patients with severe P carinii pneumonia. The efficacy of corticosteroid therapy in P carinii pneumonia, the observation that bronchoalveolar lavage (BAL) neutrophilia predicts a poor prognosis and is a marker for more severe disease, and mounting laboratory evidence” support the premise that the lung injury of P carinii pneumonia is due to an inflammatory response elicited in the host by the organism and is wrought by both cellular and humoral mechanisms.