Fungitell® ß-D-Glucan Assay
The Fungitell ß-D Glucan assay is indicated for the presumptive diagnosis of invasive fungal disease through detection of elevated levels of (1,3)- ß-D-glucan in serum. Normal human serum contains low levels of (1,3)- ß-D glucan, typically 10 to 40 pg/mL, presumably from commensal yeasts present in the alimentary canal and gastrointestinal tract. However, (1,3)- ß-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)- ß-D-glucan provides a convenient surrogate marker for invasive fungal disease.
The Fungitell ß-D Glucan assay detects (1,3)- ß-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)- ß-D-glucan, nor the Zygomycetes, such as Absidia, Mucor, and Rhizopus, which are not known to produce (1,3)- ß-D-glucan. Studies indicate Blastomyces dermatitidis is usually not detected due to little (1,3)- ß-D-glucan produced in the yeast phase.
About Fungitell
There is an increasing incidence of fungal infections by opportunistic pathogens, especially in immunocompromised patients.1-3 Invasive fungal diseases, as opportunistic infections, are common among hematological malignancy and AIDS patients and account for a growing number of nosocomial infections, particularly among organ transplant recipients and other patients receiving immunosuppressive treatments.4,5 Many fungal diseases are acquired by inhaling fungal spores originating from the soil, plant detritus, air-handling systems and/or exposed surfaces. Some opportunistic fungi are present in/on human skin, the intestinal tract, and mucous membranes.6,7 Diagnosis of invasive mycoses and fungemias is usually based on non-specific diagnostic or radiological techniques. Recently, biological markers of fungal infection have been added to the available diagnostic methods.8
ProcedureThe assay is based upon a modification of the Limulus Amebocyte Lysate (LAL) pathway. The key assay reagent is modified to eliminate Factor C, and is therefore specific for (1,3)- ß-D-glucan and does not react to other polysaccharides, including beta-glucans with different glycosidic linkages. Similar to enzyme immunoassays, the Fungitell ß-D Glucan assay is performed in microplates and read in an incubating reader. This test has been cleared or approved for diagnostic use by the U.S. Food and Drug Administration.
Same day (within 8 - 12 hours from receipt of specimen), Monday through Saturday.
Specimen Type | Test Code | CPT Code | NY Approved | Volume | Assay Range | Special Instructions |
---|---|---|---|---|---|---|
CSF | 1703 | 87449 | Yes | 2 mL (min. 0.1 mL) |
60-500 pg/mL |
|
BAL | 1709 | 87449 | Yes | 2 mL (min. 0.1 mL) |
45-500 pg/mL |
|
serum | 1710 | 87449 | Yes | 2 mL (min. 0.1 mL) |
31-500 pg/mL |
|
bronch wash | 1726 | 87449 | Yes | 2 mL (min. 0.1 mL) |
45-500 pg/mL |
|
Serum Reference Range:
Negative: Less than 60 pg/mL. Indeterminate: 60 to 79 pg/mL. Positive: Greater than or equal to 80 pg/mL
A reference range for specimens other than serum has not been established by the USFDA or Eurofins Viracor. The Fungitell ß-D Glucan assay is indicated for presumptive diagnosis of fungal infection. It should be used in conjunction with other diagnostic procedures. 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)- ß-D-glucan. This assay also does not detect the Zygomycetes, such as Absidia, Mucor and Rhizopus, which are not known to produce (1,3)- ß-D-glucan.
Assay Limitations
- The tissue locations of fungal infection, encapsulation, and the amount of (1,3)-ß-D-glucan produced by certain fungi may affect the serum concentration of this analyte. Reduced ability to contribute (1,3)-ß-D-glucan to the bloodstream can reduce the ability to detect certain fungal infections.
- The Fungitell assay does not detect fungal species such as the genus Cryptococcus which produces very low levels of (1,3)-ß-D-glucan. The assay also does not detect Zygomycetes such as Absidia, Mucor and Rhizopus which are not known to produce (1,3)-ß-D-glucan and may not be detected by the assay. In addition, the yeast phase of Blastomyces dermatitidis produces little (1,3)-ß-D-glucan and may not be detected by the assay.
- 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 three – four days for the restoration of baseline levels of serum (1,3)-ß-D-glucan, after surgical exposure to (1,3)-ß-D-glucan containing sponges and gauze. Accordingly, the timing of sampling of surgical patients should take this into account.
- Test levels were established in adult subjects. Infant and pediatric normal levels approach those of adults. Data for neonates, and infants less than six months, are lacking.
The reportable range of the assay is 31 pg/mL to 500 pg/mL. Values below 31 pg/mL are to be reported as <31 pg/mL. Values above 500 pg/mL are to be reported as >500 pg/mL, unless the sample has been diluted. If sample result is greater than 500 pg/mL, physician may order a titer of the sample. - Interpret results from samples provided in pour-off tubes with caution.
- There are reports in the peer reviewed literature of lowered assay specificity in patients with gram positive bacteremia.
- Patients with renal failure on hemodialysis utilizing cellulose membranes may have false positive results.
- Samples obtained by heel or finger stick methods are unacceptable as the alcohol-soaked gauze used to prepare the site (and potentially, the skin surface-pooling of blood) has been shown to contaminate the specimens.
- Patients whose GI tract is colonized with Candida and have mucositis may have a positive (1,3)-ß-D Glucan assay result without invasive fungal disease.
Ship Monday through Friday. Friday shipments must be labeled for Saturday delivery. All specimens must be labeled with patient's name and collection date. A Eurofins Viracor test requisition form must accompany each specimen. Multiple tests can be run on one specimen. Ship specimens FedEx Priority Overnight® to: Eurofins Viracor, 18000 W 99th St. Ste, #10, Lenexa, KS 66219.
Causes for RejectionSpecimens received outside recommended storage conditions. Specimens received grossly lipemic, icteric, hemolyzed or highly pigmented. Specimen types other than those listed in the specimen information. For BAL and Bronch wash, do not ship samples in universal transport media.
Note: Freezing serum in SST tubes can lead to hemolysis and is not recommended.
Specimens are approved for testing in New York only when indicated in the Specimen Information field above.
The CPT codes provided are based on Eurofins Viracor's interpretation of the American Medical Association's Current Procedural Terminology (CPT) codes and are provided for informational purposes only. CPT coding is the sole responsibility of the billing party. Questions regarding coding should be addressed to your local Medicare carrier. Eurofins Viracor assumes no responsibility for billing errors due to reliance on the CPT codes illustrated in this material.
Information derived from the Fungitell package insert (Associates of Cape Cod, Inc.). Fungitell is a product and registered trademark of Associates of Cape Cod, Inc.
References1 Obayashi T, Yoshida M, Mori T, et al. Plasma (1 →3)-ß-D-Glucan measurement in diagnosis of invasive deep mycosis and fungal febrile episodes. Lancet. 1995 Jan 7;345(8941):17-20.
2 Walsh TJ, Groll AH. Emerging fungal pathogens: evolving challenges to immunocompromised patients for the twenty-first century. Transpl Infect Dis. 1999 Dec:1(4):247-61.
3 Fishman JA, Rubin RH. Infection in organ-transplant recipients. N Engl J Med. 1998 Jun 11:338(24):1741-51.
4 Fridkin SK, Jarvis WR. Epidemiology of nosocomial fungal infections. Clin Microbiol Rev. 1996 Oct;9(4):499-511.
5 Alexander BD. Diagnosis of fungal infection: new technologies for the mycology laboratory. Transpl Infect Dis. 2002:4 Suppl. 3:32-7.
6 Lass-Florl C. The changing face of epidemiology of invasive fungal disease in Europe. Mycoses. 2009 May;52(3):197-205.
7 Nucci M, Anaissie E. Fungal infections in hematopoietic stem cell transplantation and solid organ transplantation - Focus on aspergillosis. Clin Chest Med. 2009 Jun;30(2):295-306
8 De Pauw B, Walsh TJ, Donnelly JP, et al. Revised definitions of invasive fungal disease from the European Organization for Research and Treatment of Cancer/Invasive Fungal Infections Cooperative Group and the National Institutes of Allergy and Infeectious disease Mycosis Study Group (EORTC/MSG) Concensus Group. Clin Infect Dis. 2008 Jun 15;46(12):1813-21.