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Test Code SHSTO Histoplasma Antibody, Serum

Reporting Name

Histoplasma Ab, S

Useful For

Aiding in the diagnosis of active histoplasmosis

Performing Laboratory

Mayo Medical Laboratories in Rochester

Specimen Type


Specimen Required


Preferred: Serum gel

Acceptable: Red top

Specimen Volume: 0.5 mL

Specimen Minimum Volume

0.5 mL

Specimen Stability Information

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

Reference Values

Mycelial by CF: negative (positives reported as titer)

Yeast by CF: negative (positives reported as titer)

Antibody by immunodiffusion: negative (positives reported as band present)

Day(s) and Time(s) Performed

Monday through Friday; 9:30 a.m.

Test Classification

This test uses a standard method. Its performance characteristics were determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.

CPT Code Information

86698 x 3

LOINC Code Information

Result ID Test Result Name Result LOINC Value
15121 Histoplasma Mycelial 20573-2
15122 Histoplasma Yeast 20574-0
15123 Histoplasma Immunodiffusion 5218-3

Clinical Information

Histoplasma capsulatum is a soil saprophyte that grows well in soil enriched with bird droppings.


The usual disease is self-limited, affects the lungs, and is asymptomatic.


Chronic cavitary pulmonary disease, disseminated disease, and meningitis may occur and can be fatal, especially in young children and in immunosuppressed patients.


Complement fixation (CF) titers ≥1:32 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.

Analytic Time

2 days

Specimen Retention Time

14 days

Reject Due To


Mild OK;Gross reject


Mild OK;Gross reject





Method Name

Complement Fixation (CF)/Immunodiffusion