Peripheral Blood Mononuclear Cells from Women with Recurrent Abortion Exhibit an Aberrant Reaction to Release Cytokines upon the Direct Contact of Human Leukocyte Antigen‐G‐Expressing Cells

PROBLEM: In search for pathogenesis of recurrent abortion, we examined whether lymphocytes/macrophages from women with recurrent abortion exhibited an aberrant ability to release cytokines upon the direct contact of human leukocyte antigen (HLA)-G. METHOD OF STUDY: The amounts of cytokines released from peripheral blood mononuclear cells (PBMCs) from women with recurrent abortion were compared with those from normal multiparous women or normal nulligravidous women when cocultured with or without HLA-G-expressing target cells. RESULTS: When cocultured with HLA-G-expressing target cells, the amount of interleukin-1 beta released from PBMCs was increased in recurrent aborters whereas it decreased in both normal multiparous and nulligravidous women. The amount of interleukin-3 released from PBMCs did not differ with or without HLA-G-expressing cells in recurrent aborters, whereas it increased in the presence of HLA-G-expressing cells in normal controls. The amount of tumor necrosis factor-alpha released from PBMCs was decreased in the presence of HLA-G-expressing cells in both recurrent aborters and normal controls. CONCLUSION: The aberrant reaction of maternal lymphocytes/macrophages in releasing cytokines upon the contact of HLA-G expressed on trophoblasts may impact negatively on trophoblastic growth, which may be pathogenic in recurrent abortion.