Lymphocyte immunization therapy: Role in Repeated Miscarriages & Implantation Failure

Abstract

The successful maternal tolerance of the semiallogeneic fetus provides an apparent immunologic paradox. Deep invasion of placental trophoblast cells into maternal uterine tissue requires tolerance of the mother’s immune system. The expression of a nonclassical pattern of human leukocyte antigen (HLA) class I molecules and the complete lack of expression of HLA class II molecules in placental tissues are the most relevant mechanisms of fetal escape from maternal immune recognition. The importance of HLA molecules in fetal tolerance by the maternal immune system is clearly demonstrated by pregnancy complications occurring in cases of abnormal HLA molecule expression at the maternal–fetal interface. In this chapter, we summarize recent evidence about the role of placental HLA molecules in normal pregnancy and how abnormal expression of HLA molecules might contribute to the pathogenesis of recurrent pregnancy loss and implantation failures.