Treatment of experimental Cryptococcus neoformans infection in newborn rabbits by airway instillation of specific antibody and surfactant.

Cryptococcosis in AIDS patients has a slow response to antifungal chemotherapy, and passive antibody treatment has thus been considered as an adjunct. Polyclonal anticryptococcal IgG dissolved in a suspension of modified natural surfactant was given intratracheally to near-term rabbits. Killing of Cryptococcus neoformans within the lungs was determined by counting the colony forming units (cfu). After 5 h a significant decrease in cfu was observed in rabbits treated with the IgG-surfactant mixture compared with control animals receiving saline. In conjunction with conventional therapy, the combined treatment of IgG-surfactant given by bronchoscopy might be used in high-risk patients to enhance killing of the yeast within the lungs.