태아가 모체의 면역 거부 반응으로부터 회피될 수 있는 기전에 관한 연구는 반세기를 지내왔지만 아직까지 규명되지 못하고 있다. 태아모체간 계면에서의 면역학적 기전이상은 자연 유산 및 습관성 유산, 태아발육제한, 임신성 고혈압 질환, 보조 생식술 후 착상실패, 태아 사망 등 각종 임신 합병증들의 병인으로 작용하므로 이 기전 규명은 매우 중요하다. 본 종설에서는 현재까지 이 면역학적 기전에 관해 밝혀진 내용들이 그 중요성의 정도순으로 기술되었다. 그 기전 이

Precise mechanism by which the fetus can escape from mother's immune rejection is not well understood yet over the last 50 years. The clarification of immune mechanism at the feto-maternal interface is very important, because this can be a common pathogenesis of various pathologic conditions including spontaneous abortion, habitual abortion fetal growth restriction preeclampsia, implantation failure after assisted reproductive techniques, and fetal death. In this review, current hypothetical contents were described with the priority of importance: 1) The center of this mechanism is cross-talk between the expression of HLA-C, E, G on the extravillous cytotrophoblasts and their receptors on decidual NK cell, 2) immunomodulation, 3) innate immunity is the main immunologic mechanism, 4) various mechanisms besides HLA system(eq. complement) may be associated. The overall balance of immunomodulation among these mechanisms should result in the outcome of each pregnancy. Further researches regarding the regulation of HLA system, roles of cytokines, complements should be followed in the future.

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