Artículos de revistas
A simple, rapid enzyme-linked immunosorbent assay for evaluating immunoglobulin G antibody avidity in toxoplasmosis
Registro en:
Diagnostic Microbiology And Infectious Disease. Elsevier Science Inc, v. 30, n. 1, n. 25, n. 30, 1998.
0732-8893
WOS:000071689700005
10.1016/S0732-8893(97)00194-6
Autor
Rossi, CL
Institución
Resumen
This article describes an enzyme-linked immunosorbent assay (ELISA) for evaluating the avidity of Toxoplasma-specific immunoglobulin (Ig) G. The test was standardized with the Falcon assay screening test (F.A.S.T.(R)) ELISA system using 6 M urea in phosphate-buffered saline for dissociating low-avidity antibodies after the antigen-antibody interaction. The avidity indices for 25 serum samples from patients with a recent Toxoplasma infection ranged from 10 to 40% (mean index = 25.3%), whereas for sera from 25 subjects with preexisting Toxoplasma immunity, the indices ranged from 58 to 94% (mean index = 73.1%). In sequential serum samples obtained over a period of up to 15 months from three patients exhibiting a persistent IgM antibody response to T. gondii, the avidity indices gradually increased during the course of infection. Avidity indices compatible with a recent infection were found in serum samples taken during the first 3 months after the onset of toxoplasmic lymphadenopathy, whereas indices compatible with the presence of a long-term infection were found in serum samples taken 7 or more months after the onset of toxoplasmic lymphadenopathy. The simplicity and short assay time (less than 1 h) make the test a potentially useful tool in assessing the avidity of Toxoplasma-specific IgG. (C) 1998 Elsevier Science Inc. 30 1 25 30