0051004
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Ehrlichia chaffeensis Antibody, IgG by IFA

E CH G
Example Reports
Negative
Positive

Ordering Recommendation

Most useful to detect antibodies during convalescent phase of disease. PCR testing is preferred; refer to Tick-Borne Disease Panel by PCR, Blood (2008670) or Ehrlichia and Anaplasma Species by PCR (2007862).

New York DOH Approval Status

This test is New York state approved.

Specimen Required

Patient Preparation
Collect

Serum Separator Tube.

Specimen Preparation

Separate from cells ASAP or within 2 hours of collection. Transfer 1 mL serum to an ARUP standard transport tube. (Min: 0.4 mL) Parallel testing is preferred and convalescent specimens must be received within 30 days from receipt of the acute specimens. Mark specimens plainly as acute or convalescent.

Storage/Transport Temperature

Refrigerated.

Unacceptable Conditions

Contaminated, hemolyzed, or severely lipemic specimens.

Remarks
Stability

After separation from cells: Ambient: 48 hours; Refrigerated: 2 weeks; Frozen: 1 year (avoid repeated freeze/thaw cycles)

Methodology

Semi-Quantitative Indirect Fluorescent Antibody (IFA)

Performed

Tue, Fri

Reported

1-5 days

Reference Interval

< 1:64  Negative-No significant level of Ehrlichia chaffeensis IgG antibody detected.
1:64-1:128  Equivocal-Questionable presence of Ehrlichia chaffeensis IgG antibody detected.  Repeat testing in 10-14 days may be helpful.
≥1:256  Positive-Presence of IgG antibody to Ehrlichia chaffeensis detected, suggestive of current or past infection.

Interpretive Data

Seroconversion between acute and convalescent sera is considered strong evidence of recent infection. The best evidence for infection is a significant change (fourfold difference in titer) on two appropriately timed specimens, where both tests are done in the same laboratory at the same time.

Compliance Category

Laboratory Developed Test (LDT)

Note

Human ehrlichiosis is a tick-borne disease caused by rickettsial-like agents. Two forms, human monocytic ehrlichiosis (HME) and human granulocytic ehrlichiosis (HGE), have been described. HME is often referred to as "spotless" or rashless Rocky Mountain spotted fever, and has been reported in various regions of the United States. The causative agent of HME has been identified as Ehrlichia chaffeensis. Infected individuals produce specific antibodies to E. chaffeensis, which can be detected by an immunofluorescent antibody (IFA) test.

Hotline History

View Hotline History

 

Hotline History

Date of Change
Test Name Change
Methodology
Performance/Reported Schedule
Specimen Requirements
Reference Interval
Interpretive Data
Note
CPT Code
Component Change
Other Interface Change
New Test
Inactive
05/15/2023
X
N/A

CPT Codes

86666

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Components

Component Test Code* Component Chart Name LOINC
0051004 Ehrlichia chaffeensis Antibody, IgG 47405-6
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.

Aliases

  • HME (Human Monocytic Ehrlichiosis)
  • Tick Borne Diseases
  • E. Chaffeensis
Ehrlichia chaffeensis Antibody, IgG by IFA