Lab Test

Histoplasma Antigen

Test Codes

MiraVista #310, BAL: EPIC: LAB6984, Beaker: XHIAB, CSF: EPIC: LAB6985, Beaker: XHIAC, Serum: EPIC: LAB6497, Beaker: XHIAS, Urine: EPIC: LAB6496, Beaker: XHIAU

Department

Send Outs

Specimen Collection Criteria

Collect: One Gold-top SST tube or plain Red-top tube.
Also acceptable: Urine, Bronchoalveolar Lavage (BAL) or Cerebrospinal Fluid (CSF) in a sterile container.

Physician Office/Draw Specimen Preparation

Let blood specimens clot 30-60 minutes then centrifuge to separate serum from cells. Transfer serum to a plastic transport tube and refrigerate (2-8°C or 36-46°F). Maintain BAL, CSF, and urine specimens refrigerated (2-8°C or 36-46°F) prior to transport.

Preparation for Courier Transport

Transport: 2.0 mL serum, BAL, CSF, or urine, refrigerated (2-8°C or 36-46°F). (Minimum: 1.2 mL serum, 0.8 mL CSF, and 0.5 mL BAL/Urine)

Rejection Criteria

Specimens not collected and processed as indicated.

In-Lab Processing

Let blood specimens clot 30-60 minutes then centrifuge to separate serum from cells. Transfer serum to a plastic transport tube and refrigerate (2-8°C or 36-46°F). Maintain BAL, CSF, and urine specimens refrigerated (2-8°C or 36-46°F) prior to transport.

Transport: 2.0 mL serum, BAL, CSF, or urine, refrigerated (2-8°C or 36-46°F). (Minimum: 1.2 mL serum, 0.8 mL CSF, and 0.5 mL BAL/Urine) 

Storage

Specimen Stability for Testing:

Room Temperature (20-26°C or 68-78.8°F): 14 days
Refrigerated (2-8°C or 36-46°F): 14 days
Frozen (-20°C/-4°F or below): Indefinite

Specimen Storage in Department Prior to Disposal:

Specimen retention time is determined by the policy of the reference laboratory. Contact the Send Outs Laboratory with any questions.

Laboratory

Sent to MiraVista Diagnostics, Indianapolis, IN.

Performed

Monday – Saturday.
Results available within 2-4 days.

Reference Range

None detected.

Results are reported as a numerical value which are interpreted as positive or negative.

Test Methodology

Quantitative Sandwich Enzyme Immunoassay (EIA).

Interpretation

Specificity of at least 98% (1).
Sensitivity varies with type of histoplasmosis (1):

  • Disseminated - 92%
  • Acute pulmonary - 44%
  • Histoplasma meningitis - 67%

Antigen can be detected in the urine of 92% and the serum of 82% of patients with disseminated disease. For patients with disseminated cases of disease with meningeal or pulmonary involvement, antigen can also be detected in the cerebralspinal fluid of 40 % and bronchoalveolar lavage fluid of 70% of patients, respectively. Antigen clears with treatment and increases with relapse, so antigen levels provide assistance in monitoring the effectiveness of drug therapy. (2)

Clinical Utility

This assay aids in the diagnosis of histoplasmosis and in monitoring the response to treatment.

Reference

  1. Diagnosis of histoplasmosis by antigen detection. N Engl J Med 1986; 314:83.
  2. Durkin M, Connolly P, Wheat J. Comparison of Radioimmunoassay and Enzyme-Linked Immunoassay Methods for Detection of Histoplasma capsulatum var. capsulatum Antigen. Journal of Clinical Microbiology 1997; 35(9):2252-2255.

CPT Codes

87385
LOINC:  BAL 53930-4, 57766-8, Urine 48952-6, Serum 51753-2

Contacts

Last Updated

3/4/2022

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