Aspergillus Galactomannan Antigen in the Bronchoalveolar Lavage Fluid for the Diagnosis of Invasive Aspergillosis in Lung Transplant Recipients

Background. The clinical utility of Platelia Aspergillus enzyme immunoassay (EIA) for galactomannan (GM) antigen detection in bronchoalveolar lavage (BAL) for the diagnosis of invasive aspergillosis (IA) in lung transplant recipients is not known. Methods. BAL fluid samples from consecutive lung transplant recipients who underwent bronchoscopy were prospectively analyzed for GM. Results. A total of 333 BAL samples from 116 patients were tested. Invasive aspergillosis was documented in 5.2% (6/116) of the patients. Samples analyzed included 9 BALs from two patients with proven IA, 19 BALs from four patients with probable IA, and 305 BALs from 110 patients without IA. At the index cutoff value of ≥0.5, the sensitivity was 60%; specificity was 95%, with positive and negative likelihood ratios of 14 and 0.41, respectively. Increasing the index cutoff value to ≥1.0 yielded a sensitivity of 60%, a specificity of 98%, and the positive and negative likelihood ratios of 28 and 0.40, respectively. Two of six patients with IA receiving antifungal prophylaxis had false-negative results. Conclusions. A Platelia EIA index cut-off ≥1.0 in the BAL fluid in a lung transplant recipient with a compatible clinical illness may be considered as suggestive of IA.