Aiding in the diagnosis of active histoplasmosis
For more information see Meningitis/Encephalitis Panel Algorithm.
Complement Fixation (CF)/Immunodiffusion (ID)
Fungal serology
histo
Histoplasma capsulatum
Histoplasma Complement Fixation
Histoplasmosis
Immunodiffusion Serology for Fungi
HISER
For more information see Meningitis/Encephalitis Panel Algorithm.
Serum
Collection Container/Tube:
Preferred: Serum gel
Acceptable: Red top
Submission Container/Tube: Plastic vial
Specimen Volume: 1.1 mL
Collection Instructions: Centrifuge and aliquot serum into plastic vial.
See Specimen Required
Gross hemolysis | Reject |
Gross lipemia | Reject |
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Serum | Refrigerated (preferred) | 14 days | |
Frozen | 14 days |
Aiding in the diagnosis of active histoplasmosis
For more information see Meningitis/Encephalitis Panel Algorithm.
Histoplasma capsulatum is a dimorphic fungus endemic to the Midwestern United States, particularly along the Mississippi River and Ohio River valleys. Infection occurs following inhalation of fungal microconidia, and subsequent clinical manifestations are largely dependent on the fungal burden at the time of exposure and the patient's underlying immune status. While the vast majority (>90%) of exposed individuals will remain asymptomatic, individuals seeking medical attention can present with a diverse set of symptoms ranging from a self-limited pulmonary illness to severe, disseminated disease. Individuals at risk for severe infection include those with impaired cellular immunity, who have undergone organ transplantation, who are HIV positive, or who have a hematologic malignancy.
The available laboratory methods for the diagnosis of H capsulatum infection include fungal culture, molecular techniques, serologic testing, and antigen detection. While culture remains the gold standard diagnostic test and is highly specific, prolonged incubation is often required, and sensitivity decreases (9%-34%) in cases of acute or localized disease. Similarly, molecular methods offer high specificity but decreased sensitivity. Serologic testing likewise offers high specificity; however, results may be falsely negative in immunosuppressed patients or those who present with acute disease. Also, antibodies may persist for years following disease resolution, thereby limiting the clinical specificity.
Anti-Yeast Antibody by Complement Fixation:
Negative (positive results reported as titer)
Antibody by Immunodiffusion:
Negative (positive results reported as band present)
Complement fixation (CF) titer results of 1:32 or higher indicate active disease. A rising CF titer is associated with progressive infection.
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.
The presence of H and/or M bands on immunodiffusion tests is considered a positive result for the presence of antibodies to Histoplasma. Presence of an H band suggests recent infection.
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.
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
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)
Monday through Friday
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.
86698 x2
Test Id | Test Order Name | Order LOINC Value |
---|---|---|
HISER | Histoplasma Ab CompFix/ImmDiff, S | 90227-0 |
Result Id | Test Result Name |
Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
|
---|---|---|
621214 | Histoplasma Yeast CompFix, S | 20574-0 |
621215 | Histoplasma Immunodiffusion, S | 90232-0 |
Change Type | Effective Date |
---|---|
New Test | 2024-06-04 |