About the Fungitell® Assay
The Fungitell® assay is a highly sensitive, rapid diagnostic test that detects (1→3)-β-D-glucan in serum in as little as one hour. (1→3)-β-D-glucan is a cell wall constituent of most medically important fungi including Candida and Aspergillus.* The assay is based upon a modification of the Limulus Amebocyte Lysate (LAL) pathway. The Fungitell reagent is modified to eliminate Factor C, and is therefore specific for (1→3)-β-D-glucan and does not react to other polysaccharides, including beta-glucans with different glycosidic linkages.
The Fungitell assay’s ability to detect picogram levels of (1→3)-β-D-glucan in serum assists clinicians in identifying invasive fungal infections early in the disease process.
Similar to enzyme immunoassays, the Fungitell assay is performed in microplates and read in an incubating reader. The assay is homogeneous, and does not require any washing steps. Run time for the assay is 40 minutes.
In May 2004, the FDA cleared the Fungitell assay for marketing, to assist in the diagnosis of fungal infections.
* The Fungitell assay is indicated for presumptive diagnosis of invasive fungal infection. It should be used in conjunction with other diagnostic procedures. The Fungitell assay does not detect certain fungal species such as the genus Cryptococcus, which produces very low levels of (1→3)-β-D-glucan. This assay also does not detect the Zygomycetes, such as Absidia, Mucor, and Rhizopus, which are not known to produce (1→3)-β-D-glucan.
For more information on the Fungitell assay please click here.
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Clinical Significance
Normal human serum contains low levels of (1→3)-β-D-glucan, typically 10-40 pg/mL, presumably from commensal yeasts present in the alimentary canal and gastrointestinal tract. Most pathogenic fungi have (1→3)-β-D-glucan in their cell walls and minute quantities are sloughed into the circulation during the life cycle. Thus, (1→3)-β-D-glucan appears in the serum in cases of invasive fungal infection (IFI). Monitoring serum (1→3)-β-D-glucan for evidence of elevated and rising levels provides a convenient surrogate marker for IFI. Levels above 80 pg/mL, in at-risk patients, are considered positive. Because a fungal infection is a dynamic process, repeat testing, typically 2-3 times per week, improves sensitivity. Time courses of serum (1→3)-β-D-glucan levels through the course of an infection have been shown to exhibit a rising level which falls in response to efficacious therapy. 1
The Fungitell® assay is indicated for presumptive diagnosis of fungal infection. It should be used in conjunction with other diagnostic procedures. The Fungitell assay does not detect certain fungal species such as the genus Cryptococcus, which produces very low levels of (1→3)-β-D-glucan . This assay also does not detect the Zygomycetes, such as Absidia, Mucor, and Rhizopus, which are not known to produce (1→3)-β-D-glucan.
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Kondori N., Edebo L., and Mattsby-Baltzer I. Circulating (1→3)-β-D-glucan and Immunoglobin G subclass antibodies to candia albicans cell wall antigens in patients with systemic candidiasis. Clinical and diagnostic Laboratory Immunology. 11(2):344-350 (2004)
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Specimen Requirements
Each sample sent to Beacon Diagnostics® laboratory for testing must be accompanied by a completed Sample Submission Form.
Please provide at least 0.5 mL of serum separated from the clot and shipped cold or frozen on ice packs or dry ice. Serum should be shipped in a sterile, clean, plastic vial (most cryogenic vials certified DNAse and RNAse free are typically suitable for use). Do not send serum in glass tubes. Samples not separated from the clot prior to shipment may incur an additional handling and preparation fee. Avoid contact between the serum and potential sources of (1→3)-β-D-glucan contamination including cellulosic filters, gauze, and cotton swabs. Note: Please be certain to use an insulated shipping container (e.g. styrofoam) and extra cold packs or dry ice in the warmer summer months to ensure that samples arrive cold.
Hemolyzed, lipemic, and icteric samples are not suitable for testing.
Samples must be shipped in accordance with federal shipping requirements for Clinical Diagnostic Specimens.
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Reference Values
Negative: Less than 60 pg/mL
Indeterminate: 60 – 79 pg/mL
Positive: Greater than or equal to 80 pg/mL
The Fungitell assay is indicated for presumptive diagnosis of fungal infection. It should be used in conjunction with other diagnostic procedures. The Fungitell assay does not detect certain fungal species such as the genus Cryptococcus, which produces very low levels of (1→3)-β-D-glucan . This assay also does not detect the Zygomycetes, such as Absidia, Mucor, and Rhizopus, which are not known to produce (1→3)-β-D-glucan.
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