EARLY NEONATAL DIAGNOSIS OF CONGENITAL TOXOPLASMOSIS - VALUE OF COMPARITIVE ENZYME-LINKED IMMUNOFILTRATION ASSAY IMMUNOLOGICAL PROFILES ANDANTITOXOPLASMA GONDII IMMUNOGLOBULIN-M (IGM) OR IGA IMMUNOCAPTURE ANDIMPLICATIONS FOR POSTNATAL THERAPEUTIC STRATEGIES

Diagnostic strategies for congenital toxoplasmosis have changed profou ndly in recent years. Immunological diagnostic methods, long considere d disappointing, can now be used at a very early stage. Over a 3-year period, 1,050 infants at risk of congenital toxoplasmosis (born to 1,0 48 mothers infected during pregnancy) were monitored for a minimum of 12 months and a maximum of 7 years. More than 6,000 serum specimens we re analyzed by comparative mother-infant immunological profiles (CIPs) based on an enzyme-linked immunofiltration assay (ELIFA) and an immun ocapture method for the detection of specific immunoglobulin M (IgM) a nd IgA. IgG antibodies were also titrated. One hundred three cases of congenital toxoplasmosis were demonstrated. The CIP-ELIFA method had a better diagnostic yield (sensitivity, 90%) than specific IgM and/or I gA detection by immunocapture assay (sensitivity, 77%). By using a com bination of these tests, congenital infection was diagnosed in the fir st month and the first 3 months of life in 90 and 94% of infants with toxoplasmosis, respectively, with a specificity of 99.8% and a positiv e predictive value of 99% at 8 months of age. This dual diagnostic app roach (ELIFA and IgM-IgA immunocapture) is highly efficient and has im portant implications for therapy. Indeed, early postnatal diagnosis ba sed on objective evidence enables therapy with pyrimethamine-sulfadoxi ne to be started immediately for 24 months, while spiramycin (which us ed to be given preventively for 9 to 12 months to all infants at risk) can be stopped after the first 3 months of life.