Normal human serum contains low levels of (1,3)- β-D glucan, typically 10 to 40 pg/mL, presumably from commensal yeasts present in the alimentary canal and gastrointestinal tract. However, (1,3)- β-D-glucan is sloughed from the cell walls during the life cycle of most pathogenic fungi. Thus, monitoring serum for evidence of elevated and rising levels of (1,3)- β-D-glucan provides a convenient surrogate marker for invasive fungal disease.
The Fungitell ß-D Glucan assay detects (1,3)- β-D-glucan from the following pathogens: Candida spp., Acremonium, Aspergillus spp., Coccidioides immitis, Fusarium spp., Histoplasma capsulatum, Trichosporon spp., Sporothrix schenckii, Saccharomyces cerevisiae, and Pneumocystis jiroveci.
The Fungitell ß-D Glucan assay does not detect certain fungal species such as the genus Cryptococcus, which produces very low levels of (1,3)- β-D-glucan, nor the Zygomycetes, such as Absidia, Mucor, and Rhizopus, which are not known to produce (1,3)- β-D-glucan. Studies indicate Blastomyces dermatitidis is usually not detected due to little (1,3)- β-D-glucan produced in the yeast phase.