[Anti-idiotypic antibodies as a physiological mechanism of inhibition of cofactor-independent antiphospolipid antibody formation].

Antiphospholipid antibodies (APA) and anti-idiotypic antiphospholipid antibodies (AiAPA) were studied in 148 women subjected to IVF. APA (IgG aCL, aPS,) levels in serum have been defined. Sera IgG fraction was also examined for the presence of AiAPA by three different methods: 1) binding of AiAPA with mouse monoclonal cofactor-independent APA (mAPA) immobilized on plate; 2) AiAPA neutralization of human affinity isolated APA and 3) mAPA binding with phospholipids. Significant difference in AiAPA levels between APA+ and APA- women subjected to IVF have been found. The mean level of AiAPA was lower in APA women subjected to IVF than in APA- women from the same group (p < 0.05). IV infusion of Ig decreased the APA level significantly as well as increased the AiAPA level in APA+ women subjected to IVF. Ig application to incubation in vitro results in decrease of APA levels in serum. Results of this study confirmed possibility of AiAPA participation in down regulation of cofactor-independent APA production in women undergoing to IVF.