BETA-D GLUCAN ASSAY

• Test Code

  317

• CPT Code

  87449

• Clinical Significance

  The Fungitell® assay measures the presence of (1→3)-β-D-Glucan in serum and CSF. Studies have shown that glucan levels become elevated in fungal infection in advance of conventional clinical signs and symptoms. The assay therefore has utility as an aid in the presumptive diagnosis of invasive fungal disease in at risk patients. Serum is the only specimen type cleared by the FDA for this assay. Performance characteristics of CSF have been validated by MiraVista Diagnostics.

• Methodology

  Colorimetric Fungitell® assay utilizing a (1→3)-β-D-Glucan -specific Limulus Amebocyte Lysate (LAL) reagent.The result is not intended to be used as the sole means for clinical diagnosis or patient management decisions.

• Limitations

  The result is not intended to be used as the sole means for clinical diagnosis or patient management decisions.

  • Does not detect certain fungal species, such as Cryptococcus sp. and Blastomyces dermatitidis, which produce very low levels of (1→3)-β-D-Glucan or Zygomycetes, such as Absidia, Mucor and Rizopus, which are not known to produce (1→3)-β-D-Glucan.
  • Positive results have been found in hemodialysis patients, subjects treated with certain fractionated blood products, such as serum albumin and immunoglobulins and in specimens or subjects exposed to glucan-containing gauze. Patients require 3-4 days for restoration of baseline levels of (1→3)-β-D-Glucan after surgical exposure to (1→3)-β-D-Glucan containing sponges and gauze. The timing of sampling from surgical patients should take this into consideration.
  • Samples obtained by finger or heel stick methods are unacceptable as the alcohol-soaked gauze used to prepare the site has been shown to contaminate the specimen.
  • The assay has not been validated for use in neonates and infants less than six months of age.
  • Patients whose GI tract is colonized with Candida and have mucositis may have a positive test result without invasive fungal disease.
  • A negative test result cannot rule out the diagnosis of invasive fungal disease.
  • Positive results should be confirmed.
• Specimen Collection
  • Serum: Collect serum specimens in serum separator or red top tube. Allow blood to clot for 30 minutes, then centrifuge. Pipette serum into a transport tube without interfering levels of (1→3)-β-D-Glucan. Most sterile polypropylene DNAase and RNAse free tubes are acceptable.
  • CSF: Submit CSF in a sterile screw cap container.
• Minimum Specimen Requirements

  Serum/CSF : 0.2 mL

• Specimen Stability
  • Room Temperature: Not acceptable.
  • Refrigerated: 5 days
  • Frozen: Indefinitely
• Specimen Rejection
  • Lipemic, hemolyzed or icteric specimens
  • May be rejected due to interference
• Transport Temperature

  Refrigerated/Frozen

• Shipping

  Ship on dry ice or frozen packs for next day service. Monday – Friday delivery

• Turnaround Time

  Testing is performed Monday-Friday.

  Serum/CSF: 1-2 days

• Reference Range

  None detected.

• Interpretative Information
  • Negative: <60 pg/mL
  • Indeterminate: 60 pg/mL – 79 pg/mL
  • Positive: 80 pg/mL – >500 pg/mL
• Additional Information

  Fungitell® is a registered trademark of Associates of Cape Cod Inc.