Increase of NK cells in decidua of women with recurrent spontaneous abortion

Various immunological mechanisms are known to be involved in maintenance of pregnancy but mechanisms underlying the failure of pregnancy in spontaneous abortion are poorly understood. Leukocytes consist a substantial percentage of endometrial stroma cells and classic natural killer cells have been proposed as immunological factor in spontaneous abortion. This study was performed to clarify the immunological role of classic NK cells in women with recurrent spontaneous abortion in the first trimester and of unknown etiology. This cell population was studied in 30 samples of decidua tissue of women with spontaneous abortion [test group] and compared with 30 samples of decidua of women undergoing elective pregnancy termination [control group]. Paraffin embedded sections were prepared from endometrial tissue samples of both groups and were dyed with specific monoclonal antibody against CD57 marker by using avidin-biotin-peroxides technique. NK cells positive for CD57 were then evaluated and counted under light microscopy with 400 magnification. Z-test was used to statistically compare NK population between test and control groups. Result showed that NK cells were scattered through stroma cells in both normal and abotion group. There was few NK cells observed in normal decidua tissue, where as this cell population was significantly increased in women with spontaneous abortion [P<0.003]. It seems that NK cells play key role in recurrent spontaneous abortion during the first trimester of pregnancy. Probably classic NK cells are activated by local cytokines and attack trophoblast cells of placenta and are thus involved in induction of spontaneous abortion

[ enhancement rate of immunity to rubella in pregnant women in Ahwaz city during 1988-98]

Rubella is a viral and acute disease which can be observed in children and adults by symptoms such as lymphoid glands inflammation and dermatitis. Its public health importance is related to teratogenic effects of primary rubella in first trimester of pregnancy. Infection in this period of pregnancy causes various anomalies such as cataract, glaucoma, deafness, coronary-vascular disease, pneumonia, encephalitis, bone damage, blood disorders, interference with the function of endocrine glands and low weight birth. In order to compare the rate of immunity to rubella in pregnant women of Ahwaz city during 1988-98, 550 serum samples were collected and assessed for anti-rubella antibody by hemagglutination inhibition [HI] and ELIZA methods. The results showed that the immunity to rubella virus has been increased from 78% to 92% during this decade. Therefore with presence of high immunity of pregnant women to rubella virus, public vaccination against rubella is not recommended in Ahwaz city

Early pregnancy decidua as a source of TGFB

Several studies have shown that decidual tissue produces soluble factors which can regulate a variety of immunosuppressive activities, but the cell type and the molecule responsible is not clearly defined. This study was performed in order to assess 1] whether active Transforming Growth Factor Beta [TGF beta] was present in decidual supernatants produced by explants, cell suspensions and endometrial granulated lymphocytes [eGL] [CD56+CD16-CD3-], and 2] define whether eGL acts as a major decidual suppressor cell for production of TGF beta in early pregnancy decidua. TGF beta assay was applied using TGF beta -sensitive CCL-64 mink lung epithelial cell line [Mv/Lu]. The supernatants from 10 human specimens of early pregnancy decidua were used in the assay in their native state, after acidification and after treatment with anti-TGF beta. The present study showed that decidual supernatants contain both TGF beta activity in which eGL CD56-positive cells have an important role in production of this suppressor factor. Studies of TGF beta activity in pathological pregnancy may be worthwhile to elucidate whether this molecule is critical for survival of the fetoplacental unit