The patient, a 39-year-old white man with a medical history of hypertension, myelodysplastic syndrome, and type 1 diabetes mellitus of 18 years' duration complicated by retinopathy and renal failure, had received a cadaveric renal transplant in 1991. He was seen in the outpatient clinic September 15, 1995, with a 2-week history of sore throat, nonproductive cough, dyspnea on exertion, fever, chills, generalized malaise, and myalgias. Medications at presentation included prednisone, 5 mg daily; cyclosporine, 125 mg twice a day; ofloxacin, 400 mg daily; ferrous polysaccharide; and insulin. On physical examination on admission to the hospital, he had a temperature of 38.4°C, and his lung fields were normal to auscultation. His chest radiograph revealed a new right upper lobe infiltrate that was not present on a radiograph taken 10 days before. His white blood cell count was 4.19×109/L; hemoglobin level, 69 g/L; and platelet count, 52×109/L; with serum levels of urea nitrogen, 9.3 mmol/L (26 mg/dL), and creatinine, 133 µmol/L (1.5 mg/dL). He had defervescence, with lessening of his symptoms, with the administration of intravenous vancomycin and ceftazidime. Blood and sputum cultures remained negative for pathogens. He was discharged from the hospital 4 days later with oral clarithromycin.