Galactomannan in bronchoalveolar lavage for diagnosing invasive fungal disease

Abstract

Rationale: Invasive fungal disease (IFD) is a significant cause of morbidity and mortality in immunocompromised patients.

Objectives: We hypothesize that galactomannan (GM), a component of fungal cell wall, as measured in bronchoalveolar lavage (BAL) might be a diagnostic adjunct in hematologic malignancies.

Methods: A total of 568 hematologic cases undergoing diagnostic bronchoscopy because of respiratory symptoms and/or suspected IFD between 2009 and 2013 at a tertiary care center in Switzerland were included in this prospective, observational cohort study. We compared accuracy of the BAL GM ELISA determination in predicting IFD as classified by the European Organization for Research and Treatment of Cancer/Invasive Fungal Infections Cooperative Group (EORTC/MSG) definition.

Measurements and main results: BAL GM was positive in 155 cases (29.2%). According to the EORTC/MSG criteria, IFD was classified as possible in 182 (34.3%), probable in 45 (8.5%), and proved in six (1.1%). BAL GM provided 50% sensitivity, 73.0% specificity, 16% positive predictive value, and 93% negative predictive value for diagnosing proven+probable IFD. Results were similar when antifungal treatment and radiologic suspicion of IFD were used as the gold standard. The area under the curve of the receiver operating characteristic curve for the diagnosis of proven+probable IFD was 0.716 (95% confidence interval, 0.638-0.794; P < 0.001).

Conclusions: GM in BAL had modest agreement with EORTC/MSG criteria for diagnosing IFD in immunocompromised patients with a high degree of antifungal exposure.

Keywords: bronchoscopy; immunosuppression; invasive pulmonary aspergillosis.