Akademik Veri Yönetim Sistemi
Mikrobiyoloji Bulteni, cilt.34, sa.3-4, ss.355-363, 2000 (Scopus)
Congenital toxoplasmosis results from primary infection of the mother during pregnancy, but not from reactivation of her latent infection in immunocompetent pregnants. Toxoplasma-IgM (Toxo-M) antibodies are generally produced in primary infections, but there is a tendency of specific IgM to persist for a long time, and even at high levels. Thus, diagnosis of primary infections or reactivations and the determination of the duration of infection have an important value for Toxo-M positive pregnants. IgG avidity tests developed in the last decade are suggested to be reliable tests to separate the low affinity antibodies produced at an early stage of infection from those with a higher binding affinity that reflect past immunity, with a single serum specimen. In this study, a total of 66 serum samples were divided into two groups according to serologic profiles and 22 serially collected serum samples taken from Toxo-M and -G positive 11 subjects with an interval of mean 60 ± 45 days, have been studied for the Toxoplasma-IgG (Toxo-G) avidities and avidity maturations respectively. As a result, 21 (44.7%) of 47 Toxo-G and -M positive sera that are classified as the first group, had low IgG avidity indicating primary toxoplasmosis, whereas 4 (21.1%) of 19 Toxo-G positive and -M negative samples that belong to the second group were found to have low IgG avidity. There was a negative correlation between IgG avidities and IgM levels (r = -0.411; p = 0.006), and positive correlation between IgG avidities and IgG levels (r = 0.518; p < 0.0001). Of 11 subjects who were followed for avidity maturation, 8 (72.7%) showed slightly elevated whereas 5 (45.5%) showed slightly declined avidity indices during our study time indicating that the expected elevation of avidity indices depending on the time was irregular.