Abstract
Objectives: To evaluate the clinical usefulness and appropriate indications of the β-D-glucan assay for the diagnosis of deep-seated mycoses. Methods: The microbiologic database of a university hospital for the years 1998–2005 was analyzed to assess the clinical usefulness of the β-D-glucan assay for the diagnosis of culture-proven fungemia or deep-seated mycoses. The reasons for initiation of antifungal therapy were surveyed and the drug costs associated with antifungal therapy were calculated using the pharmacy database for the year 2005. Results: 1) Based on the results of receiver operating characteristic curve analysis, the cutoff value of the β-D-glucan assay for the diagnosis of fungemia was determined to be 11 pg·ml−1. 2) The sensitivity and specificity of the β-D-glucan assay using this cutoff value were 76.1% and 78.7%, respectively, and the negative predictive value was 99.7%. 3) Serodiagnosis, including the β-D-glucan assay, was the second most frequent reason (24.4%) for the initiation of antifungal therapy. No microbiologic examination was performed or no fungi were detected in 81.8% of the cases treated with antifungal agents. 4) The drug cost of antifungal therapy was similar to that of broad-spectrum antibiotic therapy. Conclusions: The β-D-glucan assay, with its high negative predictive value, can be used as a screening test to exclude the possibility of deep-seated mycoses. β-D-glucan assay should be prudently conducted and its efficacy should be further investigated taking into consideration the risk factors or colonization index, in order to minimize overtreatment and the associated costs.
