Functional defect of natural immune system in an apparent immunocompetent patient with pulmonary cryptococcosis

Summary We report a case of pulmonary cryptococcosis in a 21-year-old Italian female smoker with no apparent immune disorder. In this study we demonstrated that: (i) patient's neutrophils and monocytes manifested a significant reduction of killing activity against Cryptococcus neoformans as well as Candida albicans ; (ii) the suppression was more pronounced in monocytes than in neutrophils; (iii) neutrophils and monocytes showed a significant impairment of TNF-α, IL-1β, and nitric oxide production. These results suggest that the apparent immunocompetent host with pulmonary cryptococcosis could have specific defects in natural immune system mechanisms.