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Ehrlichia chaffeensis (HME) Antibody, IgG (Sendout)

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General Information

Lab Name
Lab Code
256
External Test Id
EHRC
Description

Useful For:

  • An adjunct in the diagnosis of ehrlichiosis

  • Seroepidemiological surveys of the prevalence of the infection in certain populations

Testing Algorithm:

References
  1. Mayo Clinic Laboratories Ehrlichia chaffeensis (HME) Antibody IgG Clinical & Interpretive Information
Synonyms
E. Chaffeensis, EHRC, HME, Human Monocytic Ehrlichiosis
Components

Interpretation

Guidelines
Method

Immunofluorescence Assay (IFA)

Reference Range
Ref. Range Notes

Reference Values: <1:64

Interpretation:

A positive immunofluorescence assay (titer > or =1:64) suggests current or previous infection. In general, the higher the titer, the more likely the patient has an active infection. Four-fold rises in titer also indicate active infection.

Previous episodes of ehrlichiosis may produce a positive serology although antibody levels decline significantly during the year following infection.

Interferences and Limitations

Cautions:

Serology for IgG may be negative during the acute phase of infection (<7 days post-symptom onset), during which time detection using targeted nucleic acid amplification testing (eg, polymerase chain reaction: PCR) is recommended.

Detectable IgG-class antibodies typically appear within 7 to 10 days post-symptom onset.

IgG-class antibodies may remain detectable for months to years following prior infection. Therefore, a single time point-positive titer needs to be interpreted alongside other findings to differentiate recent versus past infection.

Other members of the Ehrlichia genus (eg, Ehrlichia ewingii) may not be detected by this assay.

References
  1. Mayo Clinic Laboratories Ehrlichia chaffeensis (HME) Antibody IgG Clinical & Interpretive Information

Ordering & Collection

Specimen Type
Blood
Collection

3 mL blood in GOLD SST or RED TOP tube

Handling Instructions

Outside Laboratories: Centrifuge sample and transfer serum to a separate plastic vial. Refrigerate serum.

Stability: Refrigerated (preferred): 14 days; Frozen: 14 days; Ambient: Unacceptable.

Reject Due To: Gross hemolysis, gross lipemia, gross icterus, heat-inactivated specimen.

Quantity
Requested: 1 mL serum
Minimum: 0.5 mL serum

Processing

Receiving Instructions

Centrifuge sample and transfer serum to a separate plastic vial. Refrigerate serum.

Login: SPMSND-;REFRIG

  • MSNDTO: MAYOSD
  • MSPTYP: SERUM
  • MTSTRQ: ;Ehrlichia Chaffeensis Antibody, IgG (Mayo Test EHRC)

Sendouts:

  • Order Mayo Test: EHRC.

Stability: Refrigerated (preferred): 14 days; Frozen: 14 days; Ambient: Unacceptable.

Reject Due To: Gross hemolysis, gross lipemia, gross icterus, heat-inactivated specimen.

Misc Sendout

Performance

Lab Department
Frequency
Performed: Monday through Friday. Report Available: 1-3 days.
Available STAT?
No
Performing Location(s)
Sendout Mayo Clinic Laboratories (Superior Drive)
800-533-1710

3050 Superior Drive NW
Rochester, MN 55901

Billing & Coding

Billing Comments

CPT: 86666