Acute Necrotizing Pneumonia in a Previously Healthy Young Adult

Diagnosis: chronic granulomatous disease (CGD) presenting with severe pulmonary nocardiosis. After 6 days of aerobic incubation, culture of a tissue sample obtained from the patient’s lung (figures 1 and 2) revealed rough, yellowish colonies. Modified acid-fast bacilli stain (figure 3) demonstrated filamentous, partially acid-fast, gram-positive bacteria with the characteristic branching and beaded appearance of Nocardia species (the isolate was further characterized as Nocardia asteroides). Because we were faced with the diagnosis of nocardiosis in a previously healthy young adult, we tested for CGD. The Nitroblue tetrazolium test (Orpagen Pharma) demonstrated !5% neutrophil color conversion. This was confirmed with flow cytometry, which failed to demonstrate any neutrophils with respiratory-burst activity, and the glucose-6-phosphate dehydrogenase level was normal (severe glucose-6-phosphate dehydrogenase deficiency can cause abnormal respiratory burst activity). CGD is a rare phagocytic disorder in which phagocytic cells are unable to kill certain bacteria and fungi after ingesting them [1, 2]. The disease is mainly recognized in children; however, there are a number of reports describing its initial presentation in adults [3–5]. The specific defect in CGD is the absence of superoxide formation; that is, a defect in the nicotinamide adenine dinucleotide phosphate oxidase enzyme. The nicotinamide adenine dinucleotide phosphate oxidase enzyme is responsible for producing O2 , which is converted to a number of bactericidal oxidants, including hydrogen peroxide. Although the X-linked and autosomal recessive patterns of in-