Preoxiredoxin family members (Prx3 and Prx4) and pregnancy disorder (recurrent pregnancy loss).

Placenta is a pregnancy unique tissue, and proper formation of placenta is a key phenomenal step for success of a pregnancy. Peroxiredoxins (Prxs) are a family of antioxidant proteins. This family is composed of six members, among which Peroxiredoxin 3 (Prx3) and Peroxiredoxin 4 (Prx4) are expressed by cytotrophoblast cells and play an important role in the implantation and a normal placentation through their antioxidant activities. Although the presence of autoantibody against several peroxiredoxin family members was reported before, there was no report regarding the presence of antibodies against Prx3 or Prx4 in human pregnancy miscarriage. So for the first time we hypothesize and indicate that uncontrolled oxidative stress, due to anti-peroxiredoxins antibodies, may affect the proper formation of the placenta and lead to placentation-related pregnancy disorders such as miscarriage. Our results indicate that two placental proteins, Prx3 and Prx4, may act as new placental immune targets. Considering the role of antioxidant defense in the protection of placenta from oxidative stress, production of antibodies against peroxiredoxins 3 and 4 may introduce a new autoimmune hypothesis for miscarriages, which is needed to be tested in the future works.