Immunodiagnosis of human granulocytic ehrlichiosis by using culture-derived human isolates.

Human granulocytic ehrlichiosis (HGE) is an emerging infection caused by an Ehrlichia species closely related to Ehrlichia equi and Ehrlichia phagocytophila. Recent advances in the isolation and cultivation of this organism have allowed us to develop an immunofluorescence assay (IFA), enzyme immunoassay (EIA), and Western immunoblotting (WB) using HL-60 cell culture-derived human isolates. Antibody was detected in sera from culture-confirmed HGE patients by IFA and EIA, and these samples were reactive when analyzed by immunoblot analysis.