Beta-D-glucan for Diagnosing Pneumocystis Pneumonia: a direct comparison between the Wako β-glucan assay and the Fungitell assay

BACKGROUND: Measuring serum beta-D-glucan (BDG) is a useful tool for supporting a qPCR-based diagnosis of suspected Pneumocystis pneumonia (PCP) on broncho-alveolar lavage (BAL) fluid. Since the 20009s, the Fungitell assay was the only BDG assay which was FDA-cleared and CE-marked. However, the Wako β-glucan test was recently also CE-marked and commercialized. METHODS: We analyzed archived sera from 116 PCP cases (based on compatible clinical and radiological findings plus BAL qPCR threshold cycle ≤ 28) and 114 controls (BAL qPCR threshold cycle > 45 and no invasive fungal infection) using the Fungitell and Wako assays in parallel and assessed their diagnostic performance using the manufacturer9s proposed cutoffs of 80 pg/mL and 11 pg/mL, respectively. RESULTS: We found Wako to be more specific (0.98 versus 0.87, p CONCLUSION: In conclusion, the Wako assay performed excellent compared to the Fungitell assay for the diagnosis of presumed PCP based on qPCR. In addition, contrary to the Fungitell assay, the Wako assay allows for single sample testing with lower inter- and intra-run variability. Finally, we propose an optimized cutoff for the Wako assay to reliably exclude PCP.