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 chemother apy, and passive antibody treatment has thus been considered as an adjunct. Polyclonal anticryptococcal IgG dissolved in a suspension of modified natu ral surfactant was given intratracheally to near-term rabbits. Killing of C ryptococcus neoformans within the lungs was determined by counting the colo ny forming units (cfu). After 5 h a significant decrease in cfu was observe d in rabbits treated with the IgG-surfactant mixture compared with control animals receiving saline. In conjunction with conventional therapy, the com bined treatment of IgG-surfactant given by bronchoscopy might be used in hi gh-risk patients to enhance killing of the yeast within the lungs.