We report the case of a 55-year-old man who exhibited a nodular pneumonia 4 months after an allogeneic hematopoietic stem cell transplantation. Culture of the bronchoalveolar lavage fluid revealed Nocardia pseudobrasiliensis. This recently described carbapenem-resistant species should be included in the differential diagnosis of fungal infection in this setting.
CASE REPORTWe report the case of a 55-year-old man who was admitted to our unit on 7 May 2008 for recent-onset cough and fever. His main medical history was multiple myeloma, diagnosed in February 2001. Treatment of the myeloma included several chemotherapy avenues, including two autologous stem cell transplantations, before he underwent allogeneic hematopoietic stem cell transplantation (HSCT) while in partial remission. Allogeneic HSCT from a matched, unrelated donor was performed at the end of January 2008 following conditioning with intravenous fludarabine (120 mg/m 2 ), oral busulfan (8 mg/kg of body weight), and anti-thymocyte globulin (ATG; 7.5 mg/kg). Prevention of graft-versus-host disease (GVHD) consisted of cyclosporine and mycophenolate mofetil (MMF). Interleukin-2 (IL-2) receptor monoclonal antibody (daclizumab) was added to steroids, tacrolimus, and MMF for steroid-resistant acute GVHD. He received posaconazole (200 mg three times a day) for primary prophylaxis of invasive fungal infection, oral penicillin V (2 millions units/day), and monthly aerosolized pentamidine (300 mg). At the time of admission to our department, the myeloma remained in stable partial response.Four months after allogeneic HSCT, the patient developed cough, dyspnea, and fever (38°C). On examination, he appeared asthenic; his blood pressure was 135/60 mm Hg, pulse beats were 90 per minute, respiratory rate was 20 per minute, and temperature was 38°C. Physical examination was normal.Laboratory test results were hemoglobin, 9.1 g/dl; polymorphonuclear cells, 1,700/mm 3 ; platelet count, 51,000/mm 3 ; serum creatinine, 142 mol/liter; C-reactive protein level, 69 mg/liter (normal is below 10 mg/liter); and partial O 2 pressure, 74 mm Hg.Chest radiography was normal, and a computed tomography (CT) scan of the chest revealed a spiculated nodule of the culmen (Fig. 1A).Blood cultures were negative. A serum Aspergillus galactomannan assay was negative. Because of neutropenia occurring a second time, the patient received piperacillin-tazobactam and amikacin. The neutropenia was related to valganciclovir. Bronchoscopy was macroscopically normal, and bronchoalveolar lavage (BAL) was performed; the fluid recovered contained 200 leukocytes per ml (with 64% macrophages and 34% polymorphonuclear neutrophils), with neither Pneumocystis jirovecii nor tumoral cells. Mycologic and viral examinations were negative, but direct microbiological examination of the BAL sample revealed numerous branched Gram-positive filamentous rods that fluoresced upon staining with Uvitex (optical brightener belonging to the stilbene derivatives that fluoresces upon excitation with UV light) (Fig. 2). Bacter...