Histoplasma Antibody Immunodiffusion
- Test Information
- Specimen Requirements
- Shipping Information
- The Histoplasma Antibody Immunodiffusion test is used for the in vitro determination of precipitating antibodies to Histoplasma sp. It is also used as an aid in the diagnosis of Histoplasmosis.
- This test detects the presence of two significant precipitin bands. Presence of both the H and the M band indicates active histoplasmosis. The presence of the M band alone indicates early or chronic disease. The M band may also be present following a recent histoplasmin skin test.
The result is not intended to be used as the sole means for clinical diagnosis or patient management decisions.
- Negative serologic tests may be observed among culturally demonstrable cases, which limits the predictive value of a negative test.
- Negative serologic results obtained during the first month may warrant repeat testing.
- Falsely negative results may be obtained when testing immunocompromised patients.
- Test results cannot be used solely, to distinguish between active infection and prior exposure.
Cross Reactivity/False Positive: moderate to low: Blastomyces, Histoplasma, Coccidioides, Aspergillus
Testing is performed on Tuesdays and Fridays.
Results released: Positive: 24 hours; Negative: 72 hours
*New positives may require confirmation
- Antibody not detected
- Will report H and M bands
- Negative: Antibody not detected
- Positive: Antibody detected
Specimen: Serum, CSF*, Plasma*
*Uncommon specimen includes incomplete validation. A ’rare specimen’ note will appear on the final report.
Serum: Collect serum specimens in serum separator tube. Allow blood to clot for 30 minutes, then centrifuge. Send serum in serum separator tube or transfer tube.
CSF, Plasma: Separator or transfer tube
Volume: 0.25 mL
Stability: Room temperature = 28 days, Refrigerated = 6 months, Frozen = indefinite
Any specimen types other than serum.
Overnight-with cold pack.