Use of IgG Avidity test in case definitions of toxoplasmosis in pregnancy

A survey network for congenital toxoplasmosis (TOXO-NET) was set up in December 1996 in Piedmont (Italy). Participants were asked to classify the infections in pregnant mothers and newborns by the criteria of the European Network on Congenital Toxoplasmosis published by Lebech in 1996. Because the IgG Avidity test is largely employed as a 2nd level test in toxoplasmosis diagnosis and it could be helpful to date infection, the co-ordinators of TOXO-NET suggested including it in the "case definition" of "probable" infection and "unlikely" infection. 117 cases of toxoplasmosis in pregnancy divided into the risk categories under Lebech's criteria were re-examined using the "new" case definitions. 77 out of 117 (65.8%) Toxoplasma gondii infections during pregnancy could be defined with only one serum sample using the IgG Avidity test. The IgG Avidity test proved a useful method to classify the Toxoplasma gondii infections in pregnancy, especially when we had only one serum sample.

[Anti-HCV antibodies in chronically dialyzed uremic patients. 1-year follow-up study]

The sera of 109 patients undergoing chronic haemodialysis treatment were reexamined after one year in order to assess changes in the anti-HVC antibody pattern in the intervening period, June 1992-June 1993. Using the ELISA II generation test, positive cases were found to have risen from 57 to 63 (from 52.3% to 57.8%); the Riba II test showed 60 positive cases (previously 52) with 3 undetermined (previously 5). The incidence of biochemical indicators of necrosis and/or cholestasis, negative in HCV patients, also presents a particular positivity (44%) in the presence of four antibody fractions. These data confirm the importance of serial determinations in anti-HCV antibody time, even if they do not correlate directly with the presence of the virus in the circulation and hence with its infecting capacity, the marker for which should be sought in the polymerase chain reaction.