Skip to Content
UW Health SMPH
American Family Children's Hospital

UW Hospital and Clinics Lab Test Directory

Test Name: Blastomyces Ag

Test Code(s): BLSTAG / HCBLSTAG

CPT Code(s): 87449

Methodology: Enzyme Immunoassay

Clinical Significance: May be used as an aid in diagnosis of disseminated or acute pulmonary blastomycosis.

Blastomyces antigen levels decline with therapy and increase with relapse, offering a method to monitor the effect of treatment and diagnose relapse.

This assay detects Blastomyces dermatitidis antigen.

Testing Site: Testing will be sent to an approved reference laboratory.

Days Performed: Mon-Fri.

Turnaround Time: Routine: 1 week.


Specimen Requirements

Collection Instructions: BAL: Sterile screw cap container. (Minimum BAL volume: 0.5 mL)
Blood: 9 mL red top or green top tube. (Minimum serum volume: 1.2 mL)
Body Fluid: Sterile screw cap container
CSF: Numbered specimen tube from sterile disposable
        lumbar puncture tray (Minimum CSF volume: 0.8 mL)
Urine: Sterile screw cap container. (Minimum urine volume: 0.5 mL)

Volume Required: Preferred: 4 mL
Pediatrics: 2 mL

Specimen Processing: Blood:  Centrifuge.  Transfer cell-free serum to plastic  
vial.  Refrigerate.

Other specimen types:  Refrigerate.

Specimen Transport: Transport specimen to laboratory. Transport with coolant pack if coming from outreach location.

Unacceptable Criteria: Samples collected in EDTA-lavender top tubes.

Stability: Ambient: 7 days
Refrigerated: 30 days
Frozen: Indefinitely


Interpretation

Test Limitations:

 Cross reactions due to closely related antigenic epitopes are seen in patients with histoplasmosis, paracoccidioidomycosis, and penicilliosis. Rare cross reactions have been seen in patients with aspergillosis and cryptococcosis.

Back to Lab Test Directory Index