Idiotypic and anti-idiotypic elastin autoantibodies: Implications for IVIg and pregnancy loss

ProblemThe aim of this study was to investigate anti-elastin and anti-anti-elastin autoantibodies in intravenous immunoglobulin (IVIg) lots as an attempt to further explain the effect of IVIg in recurrent pregnancy loss (RPL).Method of StudySerum samples of 10 female patients with RPL and 10 healthy subjects were tested for anti-elastin autoantibodies and used in competitive inhibition studies. A total of 44 IVIg lots (ZLB Behring, Switzerland) were tested for anti-elastin and anti-anti-elastin idiotypes. One way analysis of variance (ANOVA) and Least Significant Difference (LSD method) were used for statistical analysis of differences between the lots.ResultsSerum anti-elastin IgG autoantibodies were significantly higher in the study group, compared to the controls. In all lots anti-elastin IgG antibodies were identified. All lots (except two of them) showed similar dose-dependent inhibition of serum anti-elastin activity by anti-elastin anti-idiotypes in IVIg.ConclusionsAnti-elastin IgG autoantibodies were increased in patients with RPL – a finding which needs further explanation. Anti-elastin and anti-anti-elastin idiotypes were identified in different IVIg lots. The presence in IVIg of anti-idiotypes against anti-elastin autoantibodies from patients' sera could be an additional mechanism of the beneficial effect of IVIg in reproductive failure.