Due to their long survival and high cumulative corticosteroid dose, COPD patients become susceptible to unusual microorganisms that commonly affect immunosuppressed patients. Among them, fungi such as Aspergillus and Pneumocystis jiroveci and a bacterium Nocardia, a slow growing Gram-positive and acid-fast staining filamentous branching rod, have been reported in the last decade. Aspergillus can affect immunocompromised patients in different ways: by colonizing a cavity (aspergilloma), by local chronic invasion of lung parenchyma (chronic necrotizing aspergillosis or semi-invasive aspergillosis) or through a devastating vascular dissemination disease (invasive pulmonary aspergillosis). Nocardia is a pathogen that tends to act opportunistically, although it has also been reported in immunocompetent patients. It causes chronic lung infection, although systemic nocardiosis with or without central nervous system involvement is quite often found. Before the AIDS epidemic, Pneumocystis jiroveci (formerly known as Pneumocystis carinii f.sp. hominis) was known to affect malnourished patients. Recently it has been found colonizing chronic respiratory patients with conditions such as COPD or cystic fibrosis,but its role in the pathogenesis or evolution of COPD deterioration is unknown. The clinical presentation, diagnosis and therapeutic approach of each type of infection is discussed herein.
Keywords: Aspergillus spp, chronic necrotizing pulmonary aspergillosis (CNPA), Invasive pulmonary aspergillosis (IPA), Polyenes, Nocardia spp, Azoles