Anti-Annexin V Antibodies In Patients With Early Pregnancy Loss Or Implantation Failures

Objective: To describe the prevalence of annexin V antibodies (aANX) in women with early recurrent pregnancy losses (RPLs) or recurrent IVF-ET failure.Design: Retrospective data analysis.Setting: Tokai University Hospital, Kanagawa, Japan.Patient(s): Two hundred thirty-eight patients with RPLs, 48 patients with recurrent IVF-ET failure and 179 nonpregnant and 120 pregnant control group women.Intervention(s): None.Main Outcome Measure(s): ELISA was used to measure autoantibodies to annexin V.Result(s): An ELISA system developed for aANX revealed a dose-dependent relationship between annexin V and aANX. The positive/negative cutoff was set at 7 multiples of the median based on the 99th percentile of normal nonpregnant control group patients. Patients with RPLs (5.5%) or recurrent IVF-ET failure (8.3%) had a significantly increased incidence of aANX (IgG) compared with normal nonpregnant (1.1%) or pregnant control group women (0), whereas the prevalence of aANX between both patient groups or between both control groups was not statistically different. Specificity was confirmed by absorption studies using annexin V and by immunoblots.Conclusion(s): Our data show that aANX are associated with both RPLs and IVF-ET failure. We propose that anti-annexin V antibodies should be considered a risk factor for these reproductive failures. (Fertil Steril(R) 2001;76:694-9. (C) 2001 by American Society for Reproductive Medicine.).