Ehrlichia chaffeensis (HME) Antibody, IgG (Sendout)

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

Interpretation

Method

Immunofluorescence Assay (IFA)

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.

Guidelines

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

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.

Performance

LIS Dept Code

Performing Location(s)

Sendout Mayo Clinic Laboratories (Superior Drive)
800-533-1710

3050 Superior Drive NW
Rochester, MN 55901

Frequency

Performed: Monday through Friday. Report Available: 1-3 days.

Available STAT?

No

Billing & Coding

CPT codes

Billing Comments

CPT: 86666

LOINC