Mycobacterium Kansasii empyema in a renal transplant recipient case report and review of the literature.

Abstract

We describe the case of a 60-year-old man who developed fever, dyspnea, and a right pleural effusion 7 years after a renal transplant. Multiple pleural tissue and fluid cultures grew Mycobacterium kansasii. To our knowledge, only one previous case of M. kansasii empyema has been reported in the English literature. The diagnosis should be considered especially in a febrile immunocompromised patient with a pleural effusion. Successful treatment requires timely diagnosis, pleural drainage, and rifampin-based multidrug chemotherapy. Nontuberculous mycobacteria (NTM) empyema has been rarely reported in immunocompromised patients with AIDS or who have undergone organ transplantation; in immunocompetent patients with preexisting, chronic, cavitary lung disease; and in patients with postoperative infection (1, 2). M. kansasii empyema is extremely unusual. To our knowledge, the present case represents only the second report of M. kansasii empyema in the English literature. A 60-year-old man was admitted to Wilkes Barre General Hospital with a 3-week history of fever, chills, and shortness of breath. He had undergone a living-related renal transplant for membranous glomerulonephritis 7 years previously. Maintenance immunosuppression included mycophenolate mofetil and prednisone. The patient was an ex-smoker with a history of coronary artery disease requiring coronary artery bypass grafting. On physical examination, his temperature was 101°F, and his breath sounds were absent over the right lower hemithorax. Chest x-ray and computed tomography demonstrated a large, loculated right pleural effusion (Fig. 1). At thoracentesis, 1,800 mL of straw colored pleural fluid had the following characteristics: pH 7.1, white blood cell 330/mm3, red blood cell 500/mm3, lactate dehydrogenase 1,750 International Units/L, glucose 13 mg/dL, protein 4.5 g/dL, negative gram stain, and negative acid-fast bacilli smear.Figure 1. Chest x-ray (A) and computed tomography (B) demonstrating a large right pleural effusion in a 60-year-old male renal transplant patient with: Mycobacterium kansasii empyema.The right pleural cavity was drained by video thoracoscopy, and the patient was empirically started on intravenous vancomycin and piperacillin and tazobactam for presumed bacterial empyema. Three pleural tissue and two pleural fluid cultures grew M. kansasii, confirmed by commercially available DNA probe. Pleural biopsies showed granulomatous inflammation. Antibiotics were changed to isoniazid 300 mg/day, rifampin 600 mg/day, and ethambutol 400 mg/48 hr. A residual, large, chronic empyema cavity was treated with open-window thoracostomy. Eight months later, the patient is alive and well. M. kansasii is a slow-growing NTM. Diagnosis of true clinical disease requires three isolates and radiographic abnormalities. M. kansasii isolation in immunocompromised hosts or in tissue biopsy specimens represents disease. The present case of M. kansasii empyema fulfills all of these diagnostic criteria. Most M. kansasii clinical infections present as a chronic, cavitary pulmonary disease indistinguishable from Mycobacterium tuberculosis. M. kansasii also manifests as disseminated disease in immunocompromised hosts, including patients with AIDS and organ transplant recipients. Recovery of NTM in pleural fluid is uncommon. Pleural fluid cultures positive for M. kansasii are distinctly rare. In a study of 22 cases of positive NTM pleural fluid cultures at Mt. Sinai Hospital in New York from 1969 to 1983, there were no cases of M. kansasii (1). In a study of 1,069 renal transplant patients at the University of Minnesota from 1968 to 1980, there were three cases of M. kansasii infection, and all were bone and joint infections (3). In a MEDLINE literature review of solid-organ transplantation patients developing NTM infection from 1967 to 1993, there was one previous case of a positive pleural culture for M. kansasii, also a renal transplant recipient (2, 4). M. kansasii empyema seems curable. Both patients reported to date have survived. Our patient ultimately required open-window thoracostomy for adequate pleural drainage. Drugtreatment regimens for M. kansasii empyema include rifampin because of the high rates of resistance to isoniazid. In addition to rifampin, at least two other drugs to which there is no complete resistance, usually isoniazid and ethambutol, should be administered for up to 18 months (5). Douglas E. Paull Gary R. Decker Robert L. Brown 1The Department of Thoracic Surgery, Wilkes-Barre General Hospital, Wilkes-Barre, Pennsylvania 2The Department of Infectious Diseases, Wilkes-Barre General Hospital, Wilkes-Barre, Pennsylvania