Clinical microbiological case: poor radiologic evolution of pulmonary tuberculosis in a heart transplant patient

A 31-year-old Senegalese male was admitted to the hospital with persistent productive cough, fever and dyspnea. The patient had undergone an emergency heart transplant 1 year previously because of dilated myocardiopathy; give n this urgency, no purified protein derivate (PPD) test was performed prior to transplantation. Three weeks prior to admission, the patient developed high fever preceded b y shivers, cough producing yellowish-brown sputum, chest pain and increasin g dyspnea. At admission, the patient was receiving immunosuppressive treatm ent with 9 mg of prednisone and cyclosporin A. At physical examination, the patient looked extremely unwell; temperature was 39 degreesC, blood pressu re was 140/70 mmHg and heart rate was 100/min. Lung auscultation revealed b ilateral basal crepitus. The remainder of the physical examination was norm al. Laboratory tests yielded the following results: hematocrit 26%; white b lood cells 11 900 mm(3) (81% neutrophils, 8% lymphocytes, 9% monocytes); ga mma -glutamyltransferase 342 IU/L; alkaline phosphatase 322 IU/L; albumin 2 .9 g/dL. Polyclonal hypergammaglobulinemia was observed (40%). The remainin g analytic data were within normal limits. Lung function results were: pO(2 ) = 60 mmHg; pCO(2) = 25 mmHg; pH = 7.4; and HCO3 = 12.7 mEq/L. Chest X-ray s showed abundant peripherally distributed alveolar infiltrate in both lung s (Figure 1a). Fibrobronchoscopy revealed two protrusions into the bronchia l mucous membrane, one at the opening of the right main bronchus and the ot her at the border between the right superior lobar bronchus and the interme diate bronchus. Histologic examination of the transbronchial biopsy reveale d granulomatous pneumonitis and abundant acid-fast bacilli (AFB). Mycobacte rium tuberculosis, which was sensitive to common antituberculous drugs, was isolated. Treatment with isoniazid (5 mg/kg/day), pyrazinamide (15 mg/ kg/ day), ethambutol (15 mg/kg/day) and ofloxacin (200 mg mice daily) failed to elicit a satisfactory response; ofloxacin was used in preference to rifamp in because of the interaction with cyclosporin. Ten days later, sputum cult ures, induced sputum and blood cultures were all negative. Fresh chest X-ra ys showed no evidence of improvement. Both the abdominal CT scan and the EC G were perfectly normal. Graft rejection was ruled out by endomyocardial bi opsy. A second fibrobronchoscopy performed 3 weeks after the first provided no additional information, though AFB were no longer evident. Microbiologi cal analysis of bronchoalveolar lavage fluid enabled exclusion of infection by Cytomegalovirus, Legionella spp. and Pneumocystis carinii. Serology yie lded negative results for syphilis, Brucella, Leishmania, Mycoplasma, Chlam ydia, Cytomegalovirus and Rickettsia. Thick-film tests for malaria were als o negative. A CT scan of the chest showed multiple nodular opacities with a lveolar characteristics in the lower lobe of both lungs. Ground-glass opaci ties involved the central lung zones, with attenuation of peripheral vessel s. There was no evidence of lymphadenopathy or effusion. Opacities were les s numerous in the right middle and upper lobes.