ARUP's Laboratory Test Directory
| 0050625: Histoplasma Antibodies by CF |
| Test Mnemonic: HISTO | |
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#ExistMethodology>
Methodology: Complement Fixation
*ExistMethodology> #ExistPerformed> Performed: Sun-Fri *ExistPerformed> #ExistReported> Reported: 2-4 days *ExistReported> |
| Specimen Required: | |
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#ExistCollect>
Collect: One 4 mL SST.
*ExistCollect> #ExistTransport> Transport: 1 mL serum at 2-8°C. (Min: 0.5 mL) Submit specimen in an ARUP Standard Transport Tube. *ExistTransport> #ExistPedCollectTransport> Pediatric Collection/Transport: 0.3 mL serum at 2-8°C. *ExistPedCollectTransport> #ExistRemarks> Remarks: Separate serum from cells ASAP. Acute and convalescent specimens must be labeled as such; parallel testing is preferred and convalescent specimens must be received within 30 days from receipt of acute specimens. Please mark specimens plainly as "acute" or "convalescent." *ExistRemarks> #ExistConditions> Unacceptable Conditions: Severely lipemic or contaminated specimens. *ExistConditions> #ExistStability> Stability: After separation from cells: Ambient: 2 days; Refrigerated: 2 weeks; Frozen: 1 year (avoid repeated freeze/thaw cycles) *ExistStability> |
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| Reference Interval: | |||||||||
#ExistRefRangeTable>
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| Interpretive Data: | |
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#ExistInterpData>
An antibody titer greater than or equal to 1:8 is generally considered presumptive evidence of histoplasmosis. Greater than 1:32 or rising titers indicate strong presumptive evidence of histoplasmosis. Yeast phase is 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. *ExistInterpData> |
| Note: | |
| Negative fungal serology does not rule out the possibility of current infection. |
| CPT Code(s): | |
| 86698 Histoplasma mycelia; 86698 Histoplasma yeast |