SEROLOGIC RESPONSES TO BARTONELLA AND AFIPIA ANTIGENS IN PATIENTS WITH CAT-SCRATCH DISEASE

Objective. To assess the serologic response to Afipia and Bartonella, previously named Rochalimaea, in patients with cat scratch disease (CS D) and a healthy control group. Design. Prospective, controlled trial. Setting. Referral clinic and hospitalized patients in a university me dical center. Participants. Eighty patients with CSD and 57 healthy co ntrol subjects of similar age. Main Outcome Measures. The immune respo nses to Afipia felis and Bartonella henselae were evaluated by a newly developed enzyme-linked immunosorbent assay (ELISA) in patients with CSD and healthy control subjects. Responses to B henselae were also me asured by indirect fluorescent antibody (IFA) tests. Antibody levels t o Bartonella quintana were measured by ELISA and IFA in a limited numb er of patients and control subjects. Results. Of the 80 patients with clinical CSD, 56 had positive results of CSD skin tests. ELISA antibod y levels to A felis did not differ between patients and control subjec ts, but immunoglobulin M (IgM) and IgG ELISA antibodies to B henselae and B quintana were significantly higher in patients than in control s ubjects. IFA responses to B henselae and B quintana were also signific antly higher in patients than in control subjects. Conclusion. Patient s with CSD had significant serologic responses to B henselae and B qui ntana but not to A felis, suggesting that the causative agent of CSD i s antigenically related to the Bartonella genus and not to Afipia. The Bartonella IgM ELISA and IFA assay were both sensitive and specific a nd may be used to establish the diagnosis of CSD.