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UW Health SMPH
American Family Children's Hospital

UW Hospital and Clinics Lab Test Directory

Test Name: Blastomyces Ag


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


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.

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