Histoplasma Antibody Immunodiffusion

  • Test Information
  • Specimen Requirements
  • Shipping Information
  • Test Code+-


    Clinical Significance+-

    • 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.


    Fungal Immunodiffusion


    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

    Turnaround Time+-

    Testing is performed on Tuesdays and Fridays.

    Results released: Positive: 24 hours; Negative: 72 hours

    *New positives may require confirmation

    Reference Range+-

    • Antibody not detected
    • Will report H and M bands

    Interpretative Information+-

    • Negative: Antibody not detected
    • Positive: Antibody detected
  • Specimen Collection+-

    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

    Specimen Rejection+-

    Any specimen types other than serum.

  • Transport Temperature+-



    Overnight-with cold pack.