(1,3) β-D-Glucan in bronchoalveolar lavage of lung transplant recipients for the diagnosis of invasive pulmonary aspergillosis

(1,3) β-D-Glucan (BDG) is present in the cell wall of most fungi. Its detection in serum has been useful in the diagnosis of invasive aspergillosis (IA) in patients with hematologic malignancies. However, assaying for BDG did not perform well in the serum of lung transplant recipients. We undertook to study the performance of BDG in the bronchoalveolar lavage (BAL) of lung transplant recipients for the diagnosis of invasive pulmonary aspergillosis (IPA). Available and stored BAL samples from lung transplant recipients at the Toronto General Hospital between October 2007 and April 2013 were tested for BDG using the Fungitell kit from the Associates of Cape Cod Inc, Falmouth, MA, USA. The International Society for Heart and Lung transplantation (ISHLT) criteria was used for the diagnosis of IA. Of 195 samples, there were ten episodes of IA. The sensitivity and specificity of the test were 80% and 53% and 60% and 70% at 41 pg/ml and 108 pg/ml cut-offs, respectively. On excluding 52 bronchoscopies due to receipt of anti-Aspergillus therapy during specimen collection, the sensitivity and specificity improved to 75% and 91%, respectively, at a 524 pg/ml cut-off. However, only four episodes of IA remained in this analysis. Using BDG in BAL of lung transplant recipients for the diagnosis of IA, our study demonstrated moderate sensitivity and specificity.