Diagnostic performance of 1,3-beta-D-glucan serum screening in patients receiving hematopoietic stem cell transplantation

Background: The polysaccharide cell wall component, 1,3-beta-D-glucan (BDG), is used as a serum biomarker for invasive fungal infection (IFI). Patients receiving hematopoietic stem cell transplantation (HSCT) are considered a highly vulnerable group for IFI development. We evaluated the diagnostic performance of serum BDG screening in HSCT recipients.

Methods: HSCT recipients were prospectively enrolled in this study between September 2014 and August 2015. Routine serum BDG screening was performed 2-3 times weekly by using the Fungitell(®) assay. All samples were classified according to the 2008 EORTC/MSG criteria, with serum BDG results not being considered for classification. The diagnostic performance of BDG testing for IFI was calculated. BDG values ≥80 pg/mL were considered positive.

Results: A total of 308 serum samples were collected in 45 patients. The majority of 172 samples (55.8%) were obtained at the early phase (within 30 days) after allogeneic HSCT. BDG levels were significantly higher in 16 possible/probable IFI samples when compared to no evidence for IFI samples (median 170 pg/mL, interquartile range [IQR] 100-274 pg/mL vs. median 15 pg/mL, IQR 15-15 pg/mL; P < 0.001, Mann-Whitney U-test). Diagnostic performance of serum BDG screening for possible IFI/probable invasive pulmonary aspergillosis vs. no evidence for IFI was as follows: sensitivity 81%, specificity 98%, positive predictive value 65%, negative predictive value (NPV) 99%, and diagnostic odds ratio 176 (95% confidence interval 41-761).

Conclusions: Our data suggest that serum BDG testing in HSCT patients may be highly specific and associated with a very high NPV of >99%. Therefore, serum BDG may be a helpful tool to rule out IFI in HSCT patients.