Surveillance of aspergillosis by galactomannan testing, culture and histopathology in lung transplant recipients

Abstract number: O452

Arendrup M.C., Mortensen K.L., Iversen M., Milman N.

Background: The clinical utility of Aspergillus galactomannan detection (GM) in bronchoalveolar lavage (BAL) fluid for the diagnosis of aspergillosis in lung transplant recipients has recently been described.

Methods: 68 paired BAL fluid and serum samples from consecutive lung transplant recipients undergoing routine bronchoscopy were prospectively analysed for GM and results compared with culture, imaging and histopathology. Underlying diseases were chronic obstructive pulmonary disease in 24 patients, cystic fibrosis in 19, sarcoidosis in 10, alpha-1-antitrypsin deficiency in 8, pulmonal fibrosis in 8, and others in 2 patients. Patients were classified according to clinical findings during the bronchoscopy as having high risk for aspergillosis (patches involving the site of anastomosis and the airways of the lung), medium risk (patches restricted to the site of anastomosis) or low risk (no or minor patches at the site of anastomosis).

Results: A total of 68 BAL fluids from 51 recipients of single (37) or double (31) lung tranplants were investigated. 12 patients were classified as high risk patients (18%), 17 as medium (25%) and 39 as low risk patients for aspergillosis (57%). In 22/68 cases (32%) the patient received antifungal prophylaxis, which in 21/22 cases was voriconazole and in 1 case caspofungin.

The GM index in BAL fluid was >0.5 in 5/68 cases (2/39 low risk (5%), 2/17 medium risk (12%) and 1/12 high risk (8%) cases). 4 of these 5 patients were recipients of double lung transplants. In 2 cases the GM index was >0.7 (1 medium (6%) and 1 high risk patients (8%), both double lung transplant recipients) and in 1 >1.0 (high risk episode in double lung transplant recipient). No patients had positive GM in serum at any time. Six patients had a positive BAL fluid culture for aspergillus, none of whom had positive GM and 4 of whom were classified as low risk patients. Five patients had histopathological findings suggestive for aspergillus 4 of whom were classified as high risk patients. The BAL GM index in these patients was 1, 0.4, 0.3, 0.3 and 0.1 and none had positive cultures from the BAL fluid.

Conclusions: In the setting of lung transplant recipient with a frequent use of anti-aspergillus prophylaxis, BAL fluid GM appeared to correlate better with the clinical risk classification than culture, but not as good as histopathology. BAL fluid GM testing can not be regarded as a stand alone test in this setting.