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Epic Code LAB2111209 Histoplasma Antibody, Serum

Additional Codes

Mayo code: SHSTO

Epic code: LAB 2111209

Order Alias: 11271

Cerner: 2795

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Useful For

Aiding in the diagnosis of active histoplasmosis using serum specimens

Specimen Type

Serum


Specimen Required


Collection Container/Tube:

Preferred: Serum gel

Acceptable: Red top

Submission Container/Tube: Plastic vial

Specimen Volume: 0.5 mL

Collection Instructions: Centrifuge and aliquot serum into plastic vial.


Laboratory Test Directory Note:

COLLECTION NOTE: Volumes listed are in serum or plasma, draw approximately 2 1/2 times the requested volume in whole blood.

Specimen Minimum Volume

See Specimen Required

Specimen Stability Information

Specimen Type Temperature Time Special Container
Serum Refrigerated (preferred) 14 days
  Frozen  14 days

Reject Due To

Gross hemolysis Reject
Gross lipemia Reject

Day(s) Performed

Monday through Friday

Reference Values

MYCELIAL BY COMPLEMENT FIXATION (CF):

Negative (positives reported as titer)

 

YEAST BY CF:

Negative (positives reported as titer)

 

ANTIBODY BY IMMUNODIFFUSION:

Negative (positives reported as band present)

Clinical Information

Histoplasma capsulatum is a soil saprophyte that grows well in soil enriched with bird droppings. The usual disease is self-limited, asymptomatic, and affects the lungs. Chronic cavitary pulmonary disease, disseminated disease, and meningitis may occur and can be fatal, especially in young children and in immunosuppressed patients.

Cautions

Recent histoplasmosis skin tests must be avoided because the test causes a misleading rise in complement fixation titer, as well as an M precipitin band, in approximately 17% of patients having previous exposure to Histoplasma capsulatum.

 

Cross-reacting antibodies sometimes present interpretive problems in patients having blastomycosis or coccidioidomycosis.

Interpretation

Complement fixation (CF) titer results of 1:32 or higher indicate active disease. A rising CF titer is associated with progressive infection.

 

Positive immunodiffusion test results supplement findings of the CF test. The simultaneous appearance of both H and M precipitin bands indicates active histoplasmosis. The M precipitin band alone indicates early or chronic disease or a recent histoplasmosis skin test.

 

Patients infected with Histoplasma capsulatum demonstrate a serum antibody with a rising titer within 6 weeks of infection. A rising titer is associated with progressive infection. Specific antibody persists for a few weeks to a year, regardless of clinical improvement.

Reporting Name

Histoplasma Ab, S

Method Name

Complement Fixation (CF)/Immunodiffusion (ID)

Method Description

Both immunodiffusion and complement fixation (CF) tests are used to detect antibodies to Histoplasma capsulatum. For immunodiffusion, the antigen used is a culture filtrate. Histoplasmin H and M precipitins can be identified by the assay. For the CF test, antigens are histoplasmin and a yeast form antigen of Histoplasma capsulatum; the latter is more sensitive.(Roberts GD: Fungi. In: Washington II JA, ed. Laboratory Procedures in Clinical Microbiology. 2nd ed. Springer-Verlag, 1985; Bennett JE, Dolin R, Blaser MJ, eds. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases. 9th ed. Elsevier; 2020)

CPT Code Information

86698 x 3

LOINC Code Information

Test ID Test Order Name Order LOINC Value
SHSTO Histoplasma Ab, S 90227-0

 

Result ID Test Result Name Result LOINC Value
15121 Histoplasma Mycelial 20573-2
15122 Histoplasma Yeast 20574-0
15123 Histoplasma Immunodiffusion 90232-0

Report Available

2 to 7 days

Test Classification

This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.

Clinical Reference

1. Kaufman L, Kovacs JA, Reiss E: Clinical Immunomycology. In: Rose NR, de Macario ED, Folds JD, Lane HC, Nakamura RM, eds. Manual of Clinical and Laboratory Immunology. 5th ed. ASP Press; 1997

2. Deepe GS: Histoplasma capsulatum histoplasmosis. In: Bennett JE, Dolin R, Blaser MJ, eds. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases. 9th ed. Elsevier; 2020:3162-3176

Forms

If not ordering electronically, complete, print, and send Infectious Disease Serology Test Request (T916) with the specimen.