HEAT-SHOCK-PROTEIN-70 OF THE AGENT OF HUMAN GRANULOCYTIC EHRLICHIOSISBINDS TO BORRELIA-BURGDORFERI ANTIBODIES

We describe a patient with human granulocytic ehrlichiosis (HGE), a di agnosis confirmed by PCR and immunoblot analysis. Unexpectedly, immuno globulin G (IgG) directed towards an 80-kDa ehrlichial antigen (withou t detectable IgM) was present in the patient's serum in the first week of illness. Lyme disease immunoblots were reactive for IgG (but not I gM), a result indicative of prior exposure to the Lyme disease spiroch ete. Amino-terminal sequencing revealed that the 80-kDa ehrlichial ant igen was an HSP-70 homolog similar to Borrelia burgdorferi HSP-70. We conclude that antibodies against B. burgdorferi HSP-70 may cross-react with the ehrlichial heat shock protein and that this possibility must be considered when serologic test results for HGE and Lyme disease ar e interpreted.