Évaluation des performances de quatre immunoblots commercialisés pour la confirmation de la borréliose de Lyme dans une population de patients suivis en Rhône-Alpes

Summary Objective Likewise biological diagnosis resting on the serology is fussy. Immunoblot is employed to confirm antibody specificity after positive Lyme screening. Our objective: to compare analytical performances of four immunoblots commercialized for Lyme disease in our population positive for screening of Lyme disease. Material and methods We tested 42 well-defined sera of patients at different stages of Lyme borreliosis and 33 non-confirmed diagnoses. Results by four serological confirmation tests were analysed: Europe Line ® (Virotech, InGen), Ecoblot ® (Virotech, Meridian), EU Lyme WB ® (MarDx, Trinity Biotech) and Recomblot ® (Mikrogen, DiaSorin). Reactivity of two major proteins, VlsE (IgG) and OspC (IgM) were especially studied. Technical criteria were also evaluated: automated use, simplicity of reading and cost of use. Results For the patients with Lyme disease, the IgG are founded in 85,7%, 83,3%, 76,2% and 78,6% respectively by the immunoblots (Europe Line ® , Ecoblot ® , EU Lyme WB ® and Recomblot ® ) and the IgM are founded in 69%, 54.8%, 85.7% et 73.8% des IB. For the patients with suspicion of Lyme not confirmed, the IgG immunoblots are positives in 15.2%, 21.2%, 24.2% and 18.2%, respectively. For the same patients, the IgM immunoblots are positives in 27.3%, 30.3%, 45.5% and 30.3%. Immunoblot results should be interpreted carefully, and in relation to the clinical-epidemiological and biological findings. Discrepancies in findings on identical sera indicate the need to standardise serological confirmation of Lyme borreliosis infection. A good confirmatory test would need to have proven specificity in the particular population being tested, as advised by the ISO 15189 accreditation norm.