Serological cross-reactions between Bartonella quintana, Bartonella henselae, and Coxiella burnetii.
The clinical manifestations of Q fever and bartonelloses can be confused, especially in cases of infectious endocarditis. Differential diagnosis of the diseases is important because the treatments required for Q fever and bartonelloses are different. Laboratory confirmation of a suspected case of either Q fever or bartonelloses is most commonly made by antibody estimation with an indirect immunofluorescence assay. With an indirect immunofluorescence assay, 258 serum samples from patients with Q fever were tested against Bartonella henselae and Bartonella quintana antigens, and 77 serum samples from patients with infection by Bartonella sp. were tested against Coxiella burnetii antigen. Cross-reactivity was observed: more than 50% of the chronic Q fever patients tested had antibodies which reacted against B. henselae antigen to a significant level. This cross-reaction was confirmed by a cross-adsorption study and protein immunoblotting. However, because the levels of specific antibody titers in cases of Bartonella endocarditis are typically extremely high, low-level cross-reaction between C. burnetii antibodies and B. henselae antigen in cases of Q fever endocarditis should not lead to misdiagnosis, provided serology testing for both agents is performed.
La Scola
B
B
Unité des Rickettsies, Faculté de Médecine, Centre National de la Recherche Scientifique, Marseille, France.
Raoult
D
D
D016917:Angiomatosis, Bacillary / Q000175:diagnosis* / Q000276:immunology; D000907:Antibodies, Bacterial / Q000097:blood / Q000276:immunology*; D018416:Bartonella henselae / Q000276:immunology / Q000302:isolation & purification*; D018413:Bartonella quintana / Q000276:immunology / Q000302:isolation & purification*; D016997:Coxiella burnetii / Q000276:immunology / Q000302:isolation & purification*; D003429:Cross Reactions; D003937:Diagnosis, Differential; D006801:Humans; D011778:Q Fever / Q000175:diagnosis* / Q000276:immunology; D014205:Trench Fever / Q000175:diagnosis* / Q000276:immunology
D000907:Antibodies, Bacterial