DECIDUAL-TROPHOBLAST INTERACTIONS - DECIDUAL LYMPHOID-CELL FUNCTION IN NORMAL, ANEMBRYONIC, MISSED ABORTION AND ECTOPIC HUMAN-PREGNANCY

This study was designed to investigate the consequences of decidua-tro phoblast interactions on the phenotype, spontaneous and induced prolif eration and immunoregulatory potential of decidual leukocytes in norma l pregnancies (NP), anembryonic pregnancies (AP), missed abortions (MA ) and ectopic pregnancies (EP). Spontaneous proliferation of decidual non-adherent cells (NAD) from pregnancies with viable trophoblast insi de the uterus is significantly higher than proliferation of peripheral blood lymphocytes (PBL) from the same groups (P < 0.001 for NP; P < 0 .05 for AP). Spontaneous proliferation of decidual NAD cells from NP w as higher (P < 0.001) when compared with AP and EP. The induced (PHA a nd Con A) responses of PBL from women with normal and pathological pre gnancies were significantly higher than that of decidual NAD cells (P < 0.001). Higher proliferation of NAD decidual cells was obtained when Con A-stimulated NP were compared with MA and EP (P < 0.01). The inte raction of viable trophoblast with intrauterine decidua appears to be a prerequisite for the activation of NAD suppressor cells, since NAD c ells from MA produced stimulation instead of suppression, and NAD cell s from EP had no suppressive effect. On the contrary, both NAD and adh erent (AD) decidual leukocytes from NP and AP produced very strong sup pression of PHA or alloantigen-induced PBL proliferation. The contact between trophoblast and AD decidual leukocytes is not necessary for th eir suppressive function, since even higher suppression is obtained wi th the cells from ectopic pregnancies.