Details

Histoplasma Antibodies, CF

Histoplasma capsulatum Antibodies , ARUP #50625, EPIC: LAB6273, SOFT: XHPCF

Instructions

Acute and convalescent samples must be labeled as such; parallel testing is preferred and convalescent samples must be received within 30 days from receipt of the acute samples. Please mark sample plainly as "acute" or "convalescent".

Specimen Collection Criteria

Collect (preferred specimen): One Gold-top SST tube.
Also acceptable: One plain Red-top tube.

Physician Office/Drawsite Specimen Preparation

Let specimen clot 30-60 minutes then centrifuge to separate serum from cells within two hours of collection. Transfer serum to a plastic transport tube and refrigerate (2-8°C or 36-46°F).

Preparation for Courier Transport

Transport: 1.0 mL serum, refrigerated (2-8°C or 36-46°F). (Min: 0.25 mL)

Rejection Criteria

  • Severely lipemic specimens.
  • Specimens not collected and processed as indicated.

Storage

After separation from clot:
Ambient: 2 days
Refrigerated: 14 days
Frozen: 1 year (avoid repeated freeze/thaw cycles)

Performed

Sunday - Saturday.
Results available in 2-4 days.

Reference Range

Histoplasma Mycelia Antibody: Less than 1:8.
Histoplasma Yeast Antibody: Less than 1:8.

Test Methodology

Semi-Quantitative Complement Fixation.

Interpretation

  • Greater than or equal to 1:8 with either antigen are generally considered presumptive evidence of histoplasmosis.
  • Greater than 1:32 or rising titers indicate strong presumptive evidence of histoplasmosis. 

Titers of greater than or equal to 1:8 with one or both antigens may occur; yeast phase regarded as more sensitive. Approximately 90-95% of cases have positive titers to one or both antigens. Titers to mycelial antigen are higher in chronic infection. Cross reactions, usually at lower titers, may occur with other fungal disease. Rising titers suggest progression of infection. Skin tests in individuals previously exposed may cause titer elevation in 17-20% of cases.

Negative fungal serology does not rule out the possibility of current infection.

Clinical Utility

This assay aids in the diagnosis of histoplasmosis.

CPT Code

86698x2.

Test Codes

ARUP #50625, EPIC: LAB6273, SOFT: XHPCF

Last Updated

7/11/2019