HME (Ehrlichia chaffeensis) IgM & IgG IFA (203)

The Ehrlichia chaffeensis (HME) IFA is designed to detect human IgG and IgM antibodies to HME antigens in human serum. For diagnostic purposes, HME IFA test results should be used in conjunction with other information available to the diagnosing physician.

The Ehrlichia IFA assay is a two-stage sandwich assay, based upon an antigen-antibody complex formation in the following steps:

1. Binding of anti-Ehrlichia specific antibodies in human serum to fixed
2. Binding of fluorescent-labeled anti-human IgG/IgM antibodies to the human anti-Ehrlichia antibodies bound to Ehrlichia on the slide.
3. Identifying green fluorescing Ehrlichia organisms with a fluorescent microscope.

 Principle: Titers rise during the first two-to-four weeks of illness and decline over the next six-to-12 months. In patients with previously high titers, the presence of only IgG titer of less than 160 may indicate a resolving infection. If the IFA result is negative, but the clinical symptoms of HME infection are present, PCR testing is suggested. E. chaffeensis is carried by the same ticks that have also been known to cause Babesiosis, Bartonellosis and Lyme disease. Patients with positive titers should also be tested for other tick-borne diseases.

Stage of Disease: Early Disease, Late Disease

Test Methodology: IFA