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

Abstract: Problem: The 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 Study: Serum 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. Results: Serum 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. Conclusions: Anti-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. [Copyright &y& Elsevier]