THE PRESENCE OF ANTI-EBV ANTIBODIES AS THE CAUSE OF FALSE POSITIVE RESULTS IN THE DIAGNOSTICS OF LYME BORRELIOSIS

Background. Laboratory diagnosis of Lyme borreliosis is based on the detection of anti-B. burgdorferi antibodies. Mononucleosis infection can lead to false positive results in serological diagnosis of Lyme borreliosis.

Materials and methods. The experimental group comprised 60 patients diagnosed with Lyme borreliosis and 106 individuals professionally exposed to tick bites, with a positive result of ELISA anti-B. burgdorferi IgM test. The control group consisted of 150 healthy individuals. Immunoassay of antibodies to the Epstein-Barr viral capside antigen (EB-VCA) in the IgM class was carried out by the means of Western blot assay.

Results. In two patients diagnosed with borreliosis the presence of IgM antibodies to EB-VCA was confirmed. In the group of individuals professionally exposed to tick bites and in the control group no anti-EB-VCA IgM antibodies were found.

Conclusions. Anti-EBV IgM antibodies can lead to obtaining false positive results in Lyme borreliosis diagnostics. In the cases when clinical symptoms are not characteristic for Lyme borreliosis, and are accompanied by a positive result of anti-B. burgdorferi antibodies assay only in the IgM class, one has to take into consideration the occurrence of cross-reaction in the Western blot test and carry out differential diagnosis with infectious mononucleosis.