Defective antifungal activity of monocyte-derived macrophages from human immunodeficiency virus-infected children against Aspergillus fumigatus.

Invasive aspergillosis recently has been encountered in adults and children with human immunodeficiency virus (HIV) infection even without known risk factors, such as neutropenia or corticosteroid therapy. Macrophages play a significant role in the host defenses against Aspergillus organisms by ingesting conidia and preventing their germination to hyphae. The antifungal activity of peripheral blood monocyte-derived macrophages (MDM) from 19 HIV-infected children was compared with that of 16 normal controls. The phagocytic activity of patients' MDM, measured as percentage of phagocytosis, was significantly decreased compared with normal donors (P = .014). In addition, the inhibitory activity of MDM on germination of intracellular A. fumigatus conidia was significantly impaired in patients compared with normal controls (P = .016). There was no significant difference in the defects between patients with lower or higher CD4 lymphocyte counts. Impairment of antifungal activity of macrophages may contribute to the susceptibility of HIV-infected patients to aspergillosis.