Survival benefits of pulmonary cellular activation in AIDS patients with Pneumocystis infection.

Pneumocystis carinii pneumonia (PCP) is the most common life-threatening, opportunistic infection in patients with acquired immunodeficiency syndrome. Between 1984 and 1987, patients infected with human immunodeficiency virus (HIV) received bronchoalveolar lavages to confirm PCP diagnosis. Unstained slides containing bronchoalveolar cells from 20 of these patients were stored. Eight years after the last diagnostic bronchoalveolar lavage, blinded investigators immunohistochemically analyzed the unstained bronchoalveolar cells for the presence of proliferating cells and pneumocystic cysts. A significant association was found between the percentage of activated macrophages and patient survival after diagnostic bronchoalveolar lavage. On chart review, patients with higher CD4/CD8 ratios had significantly greater alveolar macrophage activation. The correlation of life span and pulmonary cellular activation in these cases (most predating retroviral therapy) suggests the importance of pulmonary cellular function to immunity and survival in patients infected with HIV.