Aspergillus Galactomannan Antigen Detection, Cerebrospinal Fluid
Use
Patients diagnosed with chronic granulomatous disease and/or Job's syndrome may yield a reduced detection of galactomannan.1 Reduced assay sensitivity may occur in patients receiving concomitant antifungal therapy.2 Penicillium species, Alternaria species, Paecilomyces species, Geotrichum species, and Histoplasma species have demonstrated reactivity with the monoclonal antibodies used in the assay and may, therefore, yield a positive test result. Positive results in patients with no clinical signs of disease have been reported, especially in young children.3 Most of these are considered to be false positives. Young children may have a positive assay result due to the presence of galactofuranaase contained in various foods (cereals) and milk. Patients receiving piperacillin/tazobactam or semisynthetic β-lactamase therapy may have false-positive results.4,5 False-positive results may also occur with use of Plasma-Lyte™ for either intravenous hydration or BAL specimen collection.6
Special Instructions
Avoid opening the specimen after collection, and do not aliquot. Transport should be in sealed tubes, as specified in the package insert, to maintain specimen integrity.
Limitations
Negative results do not exclude invasive aspergillosis. False positives have been reported, especially in young children and patients on certain therapies, such as piperacillin/tazobactam or β-lactamase. False positives can also occur with Plasma-Lyte™ use. CSF test results should be supported by other diagnostic tests, as the assay is for investigational use only. There is no established protocol for Aspergillus galactomannan detection in CSF, and performance characteristics should be verified by a confirmed diagnosis using other methods.
Methodology
Immunoassay (EIA)
Biomarkers
LOINC Codes
- 53865-2
- 80563-0
Result Turnaround Time
1-4 days
Related Documents
For more information, please review the documents below
Specimen
Cerebrospinal Fluid
Volume
2 mL
Minimum Volume
0.35 mL
Container
Sterile screw-cap, leak proof container
Collection Instructions
Collect specimen using aseptic technique. Avoid opening the specimen after collection. Do not aliquot. Transport in sealed tubes as specified by the package insert.
Patient Preparation
Usual aseptic technique
Storage Instructions
Refrigerate unopened at 2°C to 8°C for five days. After opening, store at 2°C to 8°C for 48 hours. Freeze at -70°C after five days.
Causes for Rejection
Unlabeled specimen, insufficient volume, non-sterile containers, frozen specimens stored in unknown conditions.
Stability Requirements
| Temperature | Period |
|---|---|
| Refrigerated | Stable unopened for five days, stable opened for 48 hours. |
| Frozen | Stable at -70°C after five days. |