Laboratory test for detecting IgG antibodies with low antigen avidity in the diagnosis of first infections by rubella virus, cytomegalovirus, herpes simplex virus, human herpesvirus 6, Epstein-Barr virus and Toxoplasma gondii.

摘要

With this method it is possible to investigate IgG antibodies with low avidity in the development of infections by rubella virus, herpes simplex virus, cytomegalovirus and Toxoplasma gondii (by means of ELISA) and by human herpesvirus 6 (by means of immunofluorescence), by modification of tests already available on the market, in order to improve the laboratory diagnosis thereof. To this end a substance not previously used for this purpose in these commercial tests (8 molar urea, for 5 minutes at 37 degree C, after initial incubation of the serum sample) is incorporated in order to calculate the IgG antibodies with low antigen avidity in a manner which is significant in the diagnosis. Percentages of IgG with low antigen avidity greater than 55% (by means of ELISA) or twofold reductions in the IgG titre calculated with urea (by means of immunofluorescence) are associated with a first infection by the microorganism.