Serologic response to Bartonella henselae in patients with cat scratch disease and in sick and healthy children

Indirect fluorescent antibody assay (LFA) is the most reliable test for det ecting antibody to Bartonella henselae in the diagnosis of cat scratch dise ase (CSD). Recently, an ELISA test has been proposed, but conflicting resul ts are reported. We compared IgG-IJ;A and IgG-IgM ELISA. methods in CSD pat ients and in healthy children. We also tested ELISA specificity in a large group of healthy controls and in children with lymphoma-associated lymphade nopathy and with pyogenic lymphadenitis. The ELISA procedure was positive i n 69/78 patients with CSD (sensitivity 89.6%), in 5/100 healthy children (s pecificity 95%), in 2/51 patients with non-Hodgkin's lymphoma or pyogenic l ymphadenitis (specificity 96%) and in 27/296 blood donors (specificity 91.6 %). In 34 patients with CSD, ELISA IgM and IgG responses decreased signific antly between time of diagnosis of the disease and recovery. We found signi ficantly higher IgG-ELISA titres in cat-owners, whether blood donors or hea lthy children, than in non-cat-owners. The IgG-IFA test gave positive resul ts in 69/78 patients with CSD (sensitivity 89.6%) and in 5/62 healthy contr ols (specificity 92.5%). The ELISA method is a cheap, sensitive method for determining antibody response to Bartonella henselae infection and is also important for evaluating the clinical course of the disease and the efficac y of antibiotic therapy. The high specificity of ELISA in patients with non -Hodgkin's lymphoma will help the clinician to exclude a potentially life-t hreatening disease associated with lymphadenopathy.