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HelpTest Code LAB3603 Aspergillus (Galactomannan) Antigen, Serum
Additional Codes
ASPAG
ASP AG
Useful For
Aiding in the diagnosis of invasive aspergillosis
Assessing response to therapy
Performing Laboratory
Mayo Clinic Laboratories in Rochester
Specimen Type
Serum SSTOrdering Guidance
For bronchoalveolar lavage specimens, order ASPBA / Aspergillus Antigen, Bronchoalveolar Lavage.
Specimen Required
Container/Tube: Serum gel (red-top tubes are not acceptable)
Specimen Volume: 1.5 mL
Collection Instructions:
1. Avoid exposure of specimen to atmosphere to prevent sample contamination from environment.
2. Centrifuge and send specimen in original tube. Do not aliquot or open tube.
Specimen Minimum Volume
1 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Serum SST | Refrigerated (preferred) | 14 days | SERUM GEL TUBE |
| Frozen | 14 days | SERUM GEL TUBE |
Reference Values
<0.5 index
Reference values apply to all ages.
Day(s) Performed
Monday through Friday, Sunday
CPT Code Information
87305
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| ASPAG | Aspergillus Ag, S | 44357-2 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 84356 | Aspergillus Ag, S | 44357-2 |
Interpretation
A positive result supports a diagnosis of invasive aspergillosis (IA). Positive results should be considered in conjunction with other diagnostic procedures, such as microbiologic culture, histological examination of biopsy specimens, and radiographic evidence. See Cautions.
A negative result does not rule out the diagnosis of IA. Repeat testing is recommended if the result is negative but IA is clinically suspected. Patients at risk of IA should have a baseline serum tested and should be monitored twice a week for increasing galactomannan antigen levels.
Galactomannan antigen levels may be useful in the assessment of therapeutic response. Antigen levels decline in response to antimicrobial therapy.
Method Description
The Platelia Aspergillus enzyme immunoassay (EIA) is a 1-stage immunoenzymatic sandwich microplate assay that detects galactomannan in human serum. The assay uses the rat monoclonal antibody EBA-2, which is directed against Aspergillus galactomannan. The monoclonal antibody is used to coat the wells of the microplate and bind the antigen and as the detector antibody in the conjugate reagent (peroxidase-linked monoclonal antibody).
Serum samples are heat-treated in the presence of EDTA to dissociate immune complexes and to precipitate serum proteins that could possibly interfere with the test. The treated serum samples and conjugate are added to the wells coated with the monoclonal antibody and incubated. A monoclonal antibody-galactomannan-monoclonal antibody/peroxidase complex is formed in the presence of Aspergillus antigen.
The strips are washed to remove any unbound material, and the substrate solution is added, which will react with the complex bound to the well to form a blue color reaction. The enzyme reaction is stopped by the addition of acid, which changes the blue color to yellow. The optical absorbance of specimens and controls is determined with a spectrophotometer set at 450 nm and 620/630 nm wavelengths.
Negative, cutoff (low-positive), and high-positive controls are analyzed each time the assay is performed. The presence or absence of Aspergillus galactomannan antigen in the test sample is determined by calculation of an index for the specimen. The index is the optical density (OD) value of the specimen divided by the mean OD of wells containing the cutoff control serum (low-positive control).(Package insert: Platelia Aspergillus EIA. Bio-Rad Laboratories; 10/2020)
Report Available
1 to 4 daysSpecimen Retention Time
2 weeksReject Due To
| Gross hemolysis | Reject |
| Gross lipemia | Reject |
Method Name
Enzyme Immunoassay (EIA)
Forms
If not ordering electronically, complete, print, and send 1 of the following forms with the specimen:
-General Request (T239)