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UW Health SMPH
American Family Children's Hospital

UW Hospital and Clinics Lab Test Directory

Test Name: Histoplasma Ag


CPT Code(s): 87385

Methodology: Enzyme Immunoassay

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

This assay detects Histoplasma capsulatum 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.

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


Test Limitations:

Cross reactions may occur with blastomycosis, coccidioidomycosis, paracoccidioidomycosis,  and penicilliosis marneffei, and rarely in aspergillosis.


Sputolysin and NaOH are both interfering substances.

Histoplasma Ag
Histoplasma antigen
h capsulatum

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