Aspergillus nidulans and chronic granulomatous disease: a unique host-pathogen interaction.

Invasive fungal infections are a major threat for patients suffering from chronic granulomatous disease (CGD), a primary immunodeficiency caused by a defect in the nicotinamide adenine dinucleotide phosphate (NADPH)-oxidase. Interestingly, Aspergillus (Emericella) nidulans is the second most encountered mold in CGD patients, causing almost exclusively invasive infections in this specific host, and is characterized by its aggressive behavior. A proper diagnosis is complicated by the often mild clinical presentation, the low sensitivity of the currently used diagnostic tools, and the difficulties in accurate identification of the Emericella species. According to the hitherto accepted view on the role of the NADPH-oxidase in the innate host-defense pathway, the pathogenesis of A. nidulans in CGD cannot be explained. This synopsis covers the current understanding of invasive infections caused by A. nidulans in the CGD patient and is intended to direct further research by indicating gaps in our knowledge and to guide optimal management strategies.