Objective: To investigate the role of lymphocytes in early pregnancy decidua tissue.
Methods: Immunohistochemical and in situ hybridization techniques were employed to demonstrate the population, phenotype and mediator of lymphocytes in early pregnancy decidua.
Results: In early pregnancy decidua, CD8+ suppressor/cytotoxic T lymphocytes were very few. CD4+ helper lymphocytes were few and CD56+ lymphocytes (also named NK-like cell) were abundant. CD56+ lymphocytes containing perforin protein and expressing perforin mRNA were observed.
Conclusions: The lymphocytes in early pregnancy decidua are specific and may play an important role in early pregnancy. They probably exert some positive influence on embryo implantation and placental development, and maintain the balance between trophoblastic cells and decidua tissue.