Test/Range/Collection

(1,3)-Beta-D-Glucan, serum

<60 pg/mL (Fungitell);

<20 pg/mL (Fungitec G);

<11 pg/mL (Wako)

(assay-dependent)

Red

Separate serum from cells within 2 hrs of collection, and refrigerate.

$$$

Physiologic Basis

(1,3)-Beta-D-Glucan (BDG) is a cell wall polysaccharide present in most pathogenic fungi. It is sloughed and released into the bloodstream of patients with invasive fungal infections (eg, aspergillosis or candidiasis). Monitoring serum for evidence of elevated and rising levels of BDG provides a convenient surrogate marker for invasive fungal disease.

Test performance and diagnostic cutoff values differ among serum BDG assays, including the Fungitell assay, Fungitec G test, and Wako test.

Interpretation

Positive in: Invasive fungal infections caused by Candida species, Acremonium , Aspergillus species, Coccidioides immitis , Fusarium species, Histoplasma capsulatum , Trichosporon species, Sporothrix schenskii , Saccharomyces cerevisiae, and Pneumocystis jirovecii.

Negative in: Invasive fungal infections caused by Zygomycetes (eg, Absidia, Mucor and Rhizopus ).

Comments

The BDG test is indicated for presumptive diagnosis of invasive fungal (mold) infection. It should be used in conjunction with other diagnostic procedures. A negative test result does not rule out invasive fungal disease.

Test may not detect the yeast phase of Blastomyces dermatitidis and certain fungal species such as genus Cryptococcus , which produce very little BDG.

Patients with renal failure on hemodialysis utilizing cellulose membranes may have false positive results.

Patients require 3-4 days for the return to baseline levels of BDG, after surgical exposure to BDG-containing sponges and gauze. The timing of sampling of surgical patients should take this into consideration.

Beirão F et al. State of the art diagnostic of mold diseases: a practical guide for clinicians. Eur J Clin Microbiol Infect Dis 2013;32:3.  [PMID: 22903167]

Frange P et al. An update on pediatric invasive aspergillosis. Med Mal Infect 2015;45:189.  [PMID: 26026226]

Karageorgopoulos D et al. β-D-glucan assay for the diagnosis of invasive fungal infections: a meta-analysis. Clin Infect Dis 2011;52:750. [PMID 21367728]

Schuetz AN. Invasive fungal infections: biomarkers and molecular approaches to diagnosis. Clin Lab Med 2013;33:505.  [PMID: 23931836]