Blastomyces Quantitative Antigen, Urine (316)

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Test Code: BLUAGSO

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Specimen
Performing
Clinical/Interpretive
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Coding

Synonyms/Keywords

Blastomyces Dermatitidis QNT AG

U BLUAGSO

Useful For

Aid in the diagnosis of blastomycosis

Monitor the response to therapy and to determine when treatment can be modified or stopped

Monitor Blastomyces antigen levels to help determine relapses of disease

Specimen Requirements

Fasting Required	Specimen Type	Preferred Container/Tube	Specimen Minimum Volume (allows for 1 repeat)
No	Urine	Sterile leak-proof container	0.8 mL

Collection Processing Instructions

Ship to arrive Monday through Saturday using a next day delivery service.

Samples may be shipped on dry ice, frozen ice packs or ambient.

Specimen Stability Information

Specimen Type	Temperature	Time
Urine	Room Temperature	14 days
	Refrigerate (preferred)	14 days
	Frozen	2 months

Rejection Criteria

Specimens received cold or room temperature >14 days old

Non-pipettable specimens, tissue, biopsy, sputum, bronchial brush, tracheal aspirate, FNA, bone marrow, aspirate or stool

Samples in transport media, fixative or isolator tubes

Interference

It is possible that specimens positive for Candida tropicalis, Coccidioides immitis, Coccidioides posadasii, Histoplasma capsulatum, Histoplasma duboisii, Paracoccidioides brasiliensis, Talaromyces marneffei and Aspergillus nidulans may cross-react with the Blastomyces Antigen EIA and test positive.

A variety of interfering substances, as follows, were investigated for each specimen type and none affected the Blastomyces Antigen EIA sensitivity or specificity.

Urine: glucose, protein, microalbumin, creatine, uric acid, BUN, bilirubin, nitrite, ketones, WBCs, blood/ hemoglobin, antihistamine, ascorbic acid, cough syrup, boric acid, ethyl paraben

Performing Laboratory Information

Performing Location	Day(s) Test Performed	Analytical Time	Methodology/Instrumentation
Miravista Diagnostics	Monday through Saturday	1 day	Quantitative Sandwich Enzyme Immunoassay (EIA)

Reference Lab

Miravista Diagnostics

Test Information

The MVista® Blastomyces Antigen Quantitative EIA can detect and quantify the amount of Blastomyces antigen in patient samples.

During validation testing, the sensitivity was found to be 95.00% and specificity 100% with an assay cutoff of 0.31 ng/mL.

Positive samples may require confirmation which could extend TAT.

Negative results do not exclude blastomycosis. Testing of both urine and serum offers the highest sensitivity. Failure of the antigen to rise does not exclude relapse.

Reference Range Information

Reference Interval: None Detected

Reportable Range: 0.31 ng/mL – 20.00 ng/mL

Results above 20.00 ng/mL are reported as 'Positive, Above the Limit of Quantification'

When tested in cultures of 10⁵ – 10⁶ organisms/mL, cross-reactions occurred with Histoplasma spp., Coccidioides spp., Paracoccidioides brasiliensis, Talaromyces marneffei, Aspergillus nidulans, and Candida tropicalis.

Interpretation

None Detected: <0.31 ng/mL
Positive: ≥0.31 ng/mL – 20.00 ng/mL
Positive Above the Limit of Quantifications
Results greater than 20.00 ng/mL fall outside the linear range of the assay. These results are positive, but not accurately quantifiable.

Results should be correlated with clinical presentation and history

Outreach CPTs

CPT	Modifier (if needed)	Quantity	Description	Comments
87449		1