Incidence of a novel infectious agent in patients with advanced cardiovascoular diseases in awaiting heart transplantation.

Aim: Bartonella henselae, the etiologic agent of cat-scratch disease, causes a self-limited syndrome of fever and regional lymphadenopathy in immunocompetent hosts. In immunocompromised hosts, however, B. henselae can cause severe disseminated disease and pathologic vasoproliferation known as bacillary angiomatosis or bacillary peliosis. The spectrum of disease, diagnosis and management of B. henselae infection in solid organ transplant recipients has not been well characterized. The purpose of this study has been to determine the seroprevalence of B. henselae in patients awaiting heart transplantation, in our Regional Reference Transplantation Centre. Methods: The diagnosis of B. henselae is usually based on serological methods (IgM, IgG). Immunofluorescent assays (IFA) are used for the detection of IgG or IgM antibodies against specific antigens. Bartonella IgM and IgG test kits are designed to detect the antigen-antibody complexes when diluted sera are presented with Bartonella antigens on commercially produced slides. A fluorescein-labeled anti-IgG or IgM conjugate is responsible for visualization of reactions. Results: Serum samples from 21 (16M, 5F) patients awaiting heart transplantation, with a median age of 53 ± 15SD (range 8-68 years) and 20 healthy donors (10M and 10F), with a median age of 37 ± 5.9SD (range 28-49 years) were examined by indirect immunofluorescence assay. In our study we have found, in patients awaiting heart transplantation, a B. henselae antibody positivity rate of 19.04% (4/21) and in particular, 1/21 (4.76%) patients presented IgM while 3/21 (14.28%) presented IgG. All healthy donors were found negative. Conclusions: Our preliminary serological data seems to indicate that B. henselae is present in our area and more interestingly it can be also present in patients awaiting heart transplantation. Thus, on the basis of our data, we would recommend the importance of including B. henselae diagnosis also in pre-transplant patients.