Aspergillosis: The most common community-acquired pneumonia with gram-negative Bacilli as copathogens in stem cell transplant recipients with graft-versus-host disease.

We retrospectively reviewed all cases of pneumonia that required hospitalization among allogeneic hematopoietic stem cell transplant (HSCT) recipients with graft-versus-host disease (GVHD) during the period of January 1996 through July 1999. Twelve patients were identified among 88 allogeneic HSCT recipients. All had chronic GVHD and were receiving corticosteroid therapy. Ten of the 12 patients had pulmonary aspergillosis (PA). For 6 of these 10 patients, a gram-negative bacterial pathogen was concurrently isolated from respiratory specimens. At least one-half of the patients with PA had an initial presentation suggestive of bacterial pneumonia; PA was only suspected on the basis of chest CT findings. Aspergillosis is the most common cause of community-acquired pneumonia among allogeneic HSCT recipients with GVHD. CT must be used to exclude an underlying fungal cause in patients who present with a gram-negative pneumonia.