Circulating interferon-gamma- and interleukin-4-secreting cells in recurrent spontaneous abortions.

PROBLEM: Are recurrent spontaneous abortions (RSAs) associated with deviation of circulating cytokine-secreting cells? METHOD OF STUDY: Interferon (IFN)-γ- and interleukin (IL)-4-secreting cells were identified by enzyme-linked immunospot (ELISPOT) in blood from 34 women with RSA. Samples were taken before pregnancy and/or pregnancy weeks 7–10, 17–20, and after terminated pregnancy. Eleven healthy primigravidae and 10 nonpregnant women served as controls. RESULTS: No significant difference in numbers of IFN-γ- and IL-4-secreting cells was noted within the RSA group when abortions and successful pregnancies were compared in samples taken before pregnancy. The number of IFN-γ- as well as IL-4-secreting cells in pregnancy weeks 17–20 in the RSA group was significantly higher compared with before pregnancy, pregnancy weeks 7–10, and after pregnancy. In samples from non-pregnant women, the number of IFN-γ- and IL-4-secreting cells was significantly higher in the RSA group compared with controls. CONCLUSIONS: Our results do not indicate a systemic shift in the general balance between T helper 1- and T helper 2-type cytokine pattern. A local shift at the fetomaternal interface seems more probable.     

Prevention of recurrent spontaneous abortion by intravenous immunoglobulin: a double-blind placebo-controlled study

The aim of this study was to evaluate the therapeutic efficacy of intravenous immunoglobulin (IVIG) in the prevention of recurrent spontaneous abortion (RSA). In a double-blind, randomized, placebo-controlled study, 41 women with a history of unexplained recurrent spontaneous abortion were treated with IVIG or saline infusions during pregnancy. The birth of a child was considered a successful outcome. The overall success rate was 77% in the IVIG group compared with 79% in the placebo group. For women with primary RSA the success rates were 82 (IVIG) and 89% (placebo), and for women with secondary RSA the rates were 73 (IVIG) and 70% (placebo). We found no statistically significant difference in treatment results between IVIG and placebo.     

Circulating cytokines and CD30 in normal human pregnancy and recurrent spontaneous abortions

Concentrations of the T-helper (Th) 1 cytokines interleukin (IL)-2, tumour necrosis factor (TNF) -alpha, TNF-beta and interferon-gamma, Th2 cytokines IL-4, IL-5, IL-6, IL-10 as well as those of soluble CD30 in sera have been examined during the three trimesters of gestation, at delivery in normal pregnancy, and at the time of spontaneous abortion in women with a history of unexplained recurrent spontaneous abortion (RSA). Significantly higher concentrations of the Th2 cytokines IL-6 and IL-10 were found at normal delivery than in women with RSA, and conversely significantly increased concentrations of the Th1-type cytokine TNF-alpha were found in RSA as compared with successful pregnancy. In abortion-prone women who had a successful pregnancy, significantly higher concentrations of IL-6 and significantly lower concentrations of TNF-alpha were found as compared with abortion-prone women who had another abortion, supporting the notion that Th2- and Th1-bias are associated with successful and unsuccessful pregnancy respectively. Serum CD30 concentrations did not correlate with the outcome of pregnancy. These findings support observations drawn from experiments on the cytokine secretion profiles of peripheral blood mononuclear cells and decidual lymphocytes which suggest that normal pregnancy is Th2-biased and that unexplained RSA is associated with Th1-type reactivity.     

Cytokine production by maternal lymphocytes during normal human pregnancy and in unexplained recurrent spontaneous abortion

It has been proposed that successful pregnancy is a T helper 2-type phenomenon, and that T helper (Th)1-type reactivity is deleterious to pregnancy. The objective of this study was to compare the concentrations of Th1 and Th2 cytokines produced by peripheral blood mononuclear cells from women undergoing unexplained recurrent spontaneous abortion (RSA) with those produced during normal pregnancy at a similar gestational stage. The control group consisted of 24 women with a history of successful pregnancies and the abortion group comprised of 23 women with a history of unexplained RSA. Blood from the control group was obtained at the end of the first trimester as gestational age controls for the abortion group from whom blood was collected at the time of abortion. Phytohaemagglutinin-stimulated peripheral blood cell culture supernatants were analysed for concentrations of cytokines. Significantly higher concentrations of Th2 cytokines were produced by the first trimester normal group than by the RSA group, while significantly higher concentrations of Th1 cytokines were produced by the abortion group as compared to first trimester normal pregnancy, indicating a distinct Th2-bias in normal pregnancy and a Th1-bias in unexplained RSA.     

Association of the maternal 14-bp insertion polymorphism in the HLA-G gene in women with recurrent spontaneous abortions

Human leukocyte antigen (HLA)-G has been postulated as an important immunotolerant molecule in maintaining fetal-maternal relationship. Recent reports indicated that the 14-bp deletion/insertion polymorphism in exon 8 of HLA-G gene influences HLA-G mRNA stability and isoform splicing patterns, thus modulating the levels of HLA-G expression. This might play an immunomodulatory role of HLA-G during implantation and pregnancy. In the present study, 109 unrelated fertile control women and 79 women who had experienced recurrent spontaneous abortion (RSA) were genotyped for the 14-bp insertion/deletion polymorphism. No significant difference was observed in the distribution of 14-bp insertion/deletion genotype between controls and the RSA group. However, a greater number of 14-bp insertion alleles exist in the RSA group than in the controls.     

Th1 and Th2 cytokine profiles in recurrent aborters with successful pregnancy and with subsequent abortions

BACKGROUND: This study compared Th1-Th2 cytokine profiles in a subgroup of recurrent aborters who had an abortion with those in a subgroup of recurrent aborters who had a successful pregnancy. METHODS: Fifty-four women with a history of at least three normal pregnancies, 24 women with a history of recurrent spontaneous abortion (RSA) followed by abortion (RSA-->A) and 39 women with a history of RSA followed by normal pregnancy (RSA-->N) were studied. Blood samples and placentas were obtained at the time of delivery or abortion; peripheral blood mononuclear cells were stimulated separately with phytohaemagglutinin and with autologous placental cells, and the secreted cytokines estimated. RESULTS: Peripheral blood mononuclear cells from the RSA-->N subgroup secreted higher concentrations of Th1-type cytokines as compared with normal pregnant women, indicating a higher Th1 bias in these women. However, women in the RSA-->N subgroup had significantly higher concentrations of Th2 cytokines as compared with women in the RSA-->A subgroup. A comparison of Th1:Th2 cytokine ratios indicated a higher Th2 bias in RSA-->N women as compared with RSA-->A women. CONCLUSIONS: We conclude that abortion-prone women who proceed to have successful pregnancy are more Th2-biased than abortion-prone women who abort, and that recurrent aborters who undergo spontaneous abortion have a stronger Th1 bias than aborters who have normal pregnancy.     

Impact of Age on Reproductive Outcome in Women With Recurrent Spontaneous Abortions and Infertility of Immune Etiology

The objective of this paper is to determine whether age has any impact on conception rate, pregnancy outcome, or autoimmune status in women with recurrent spontaneous abortions (RSA) and infertility of immune etiology. One hundred twenty-four women with 3 or more RSA and 36 women with unexplained infertility were prospectively studied. Maternal anti-paternal lymphocyte antibodies and autoantibodies to phospholipids and nuclear antigens were tested. All achieved an adequate alloimmune recognition after lymphocyte immunization and followed for 1 year with optimal preconception autoimmune treatment. Conception rate and pregnancy outcome were prospectively studied. 1) 10.1% of women with RSA and 30.6% of women with infertility failed to achieve a pregnancy after 1 year of trial (P=0.0084); 2) in women with RSA, the number of previous fetal death after 28 weeks of gestation was significantly higher in women who failed to achieve a pregnancy within 1 year when compared to women who became pregnant (P=0.0296). Conception rate was not different with advancing age; 3) women with infertility demonstrated significantly higher incidence of anti-phosphatidylethanolamine antibody when compared to women with RSA (P=0.052); 4) in women with infertility, those who failed to achieve a pregnancy were significantly older (P=0.0012) and demonstrated a higher incidence of autoantibodies to phosphatidic acid than women with infertility who became pregnant (P=0.0339); 5) the subsequent spontaneous abortion rate while on optimal immune therapy was the same in the women with RSA (39.3%) and women with infertility (32%). Spontaneous abortion rate of women with RSA or infertility was not different among four age groups; 6) the presence of anti-cardiolipin antibody (P=0.0055) and higher gravidity (P=0.0354) correlated significantly with pregnancy failure in women with a history of infertility. The prevalence of auto-antibodies to phospholipids and nuclear components was not different among four age groups in women with RSA or infertility. Age does not affect pregnancy outcome or conception rate in women with RSA. In women with infertility of immune etiology, conception rate was significantly reduced over age 40 although pregnancy outcome was no different with advanced age.     

The effect of male factors in repeated spontaneous abortion: lesson from in-vitro fertilization and intracytoplasmic sperm injection

Between 6.5 and 21% of pregnancies result in spontaneous abortion.The incidence of repeated spontaneous abortion. The incidenceof repeated spontaneous abortion (RSA) is, however, lower: 0.05-1.0%of pregnancies. These values vary, not only according to thepopulations studied and the means of diagnosing the miscarriages,but also to the age and the parity of the patient: 4% at 20years of age versus 16% after 35 years. These differences aregreater if biochemical pregnancies are taken into account. Theaetiologies of RSA are multiple and at times even multifactorial.While certain aetiologies, such as chromosomal, anatomic, hormonal,immunological or unexplained anomalies, have been extensivelyexplored, the sperm characteristics likely to influence thequality of the conceptus have rarely been examined. This reviewexamines the male factor's contribution in RSA.     

Elevated expression of activation molecules by decidual lymphocytes in women suffering spontaneous early pregnancy loss.

The purpose of this study was to investigate, quantify and compare the expression of activation markers by decidual leukocytes in sporadic spontaneous early pregnancy loss and apparently normal first trimester human pregnancy. Decidua was obtained from 18 therapeutic abortions and 20 sporadic spontaneous abortions at 8-12 weeks gestational age. Cryostat sections were labelled by the avidin-biotin complex-peroxidase method using monoclonal antibodies specific for CD45, CD56, CD3, human leukocyte antigen (HLA) DR, CD69, CD25 and very late antigen (VLA)1. Positive cells were quantified and the results were analysed using the Mann-Whitney statistical test. Significantly increased numbers of CD69-positive and CD25-positive cells were detected in spontaneous abortion decidua, when compared with therapeutic abortion decidua. Approximately 50% of women experiencing spontaneous miscarriage also contained significantly elevated numbers of HLA DR-positive cells within decidua. Double immunohistochemical labelling studies demonstrated that the CD25-positive and CD69-positive cells in spontaneous abortion decidua were CD3-positive T cells rather than CD56-positive granulated lymphocytes. Immunological dysfunction within endometrium may account for a proportion of sporadic spontaneous abortions.     

Peripheral natural killer cytotoxicity and CD56(pos)CD16(pos) cells increase during early pregnancy in women with a history of recurrent spontaneous abortion

For diagnostic purposes we assessed peripheral natural killer (NK) cell cytotoxicity and NK and T cell numbers to assess their putative predictive value in recurrent spontaneous abortion (RSA). A total of 43 women with subsequent pregnancy, 37 healthy controls and 39 women successfully partaking in an in-vitro fertilization (IVF) procedure, were included in the study. We show that before pregnancy, levels of NK cytotoxicity and numbers of both single CD56(pos) and double CD56(pos)CD16(pos) cells were similar between RSA women and controls. But notably, within the RSA group, NK cell numbers of <12% were strongly associated with a subsequent pregnancy carried to term. Supplementation of folic acid led to an increase of single CD56(pos) cells, but cytotoxic function appeared unaffected. The expression pattern of killer inhibitory receptors on CD56(pos) cells was not different between patients and controls. A longitudinal study revealed that, compared with controls, in RSA women higher numbers of double CD56(pos)CD16(pos) cells were present during early pregnancy, paralleled by an increase in cytotoxic NK cell reactivity. The single CD56(pos) population decreased in number. In conclusion, the analysis of peripheral NK cell characteristics appears a suitable diagnostic tool in RSA. Immunomodulation aimed at NK cell function appears a promising therapeutic measure.     

Pre-conceptional natural killer cell activity and percentage as predictors of biochemical pregnancy and spontaneous abortion with normal chromosome karyotype

PROBLEM: The aim of the present study was to determine whether pre-conceptional natural killer (NK) cell activity and percentage are predictive of subsequent spontaneous abortion in women with recurrent spontaneous abortion (RSA). METHOD OF STUDY: Pre-conceptional NK cell activity and percentage in peripheral blood of women who had a history of two or more RSA was prospectively assessed. The 51Cr release assay and flow cytometric analysis were performed. A total of 113 RSA women were recruited, and 85 conceived later. RESULTS: Pre-conceptional NK cell activity/percentage values in women whose next pregnancies ended in biochemical pregnancy and spontaneous abortion with normal fetal karyotype (n = 17, median 47%/17.1%), but spontaneous abortion with abnormal karyotype (n = 9, 27%/15.7%), were higher than those in live births (n = 59, 33%/13.1%). High values of pre-conceptional NK cell activity (> 46%; relative risk 3.6, 95%CI 1.6-8.0) and percentage (> 16.4%; 4.9, 1.7-13.8) were found to predict biochemical pregnancy and spontaneous abortion with normal karyotype in the next pregnancy. CONCLUSION: Pre-conceptional NK cell abnormalities were predictive of spontaneous abortion with normal fetal karyotype.     

Mitogen-induced cytokine responses of maternal peripheral blood lymphocytes indicate a differential Th-type bias in normal pregnancy and pregnancy failure

PROBLEM: Profiles of Th1- and Th2-type cytokines were studied in women with a history of successful pregnancy and in women with a history of unexplained recurrent spontaneous abortions (RSA) with the objective of elucidating Th1- and Th2-type bias in normal pregnancy and pregnancy failure. METHOD OF STUDY: Peripheral blood mononuclear cells (PBMCs) from 54 women with a history of normal pregnancy and 23 women with a history of unexplained RSA, obtained at delivery or on the day of abortion, respectively, were stimulated with phytohemagglutinin (PHA), followed by the estimation of four Th2 cytokines and four Th1 cytokines. RESULTS: Significantly greater levels of Th2 cytokines were produced by the normal group than by the RSA group. On the other hand, significantly higher levels of Th1 cytokines were produced by the RSA group than by the normal pregnancy group. CONCLUSIONS: These data support the concept that unexplained recurrent spontaneous abortion is associated with an increase in Th1-type reactivity, while Th2 dominance is a feature of successful pregnancy.     

Fetal rejection: infertility and immunity

Defective reaction toward fetal alloantigens could result in both recurrent spontaneous abortions (RSAs) and recurrent early pregnancy failures (REPFs), the latter existing in couples with unexplained infertility and multiple failures of implantation after in vitro fertilization embryo transfer. Immunological mechanisms leading to RSA and REPF seem to be different, although both syndromes probably have a genetic background that has not been identified so far. Despite the fact that antiphospholipid syndrome is a well-established cause of repeated pregnancy loss, the role of different autoantibodies existing in RSA and REPF patients needs to be elucidated. Immunotherapy is believed to correct the detrimental immune reactions; however, its real effectiveness and safety for the treatment of distinct forms of pregnancy loss need to be reconsidered.     

Possible mechanisms of immunotherapy for maintaining pregnancy in recurrent spontaneous aborters: analysis of anti-idiotypic antibodies directed against autologous T-cell receptors

We examined whether immunotherapy for recurrent spontaneous abortion (RSA) using paternal lymphocytes induces anti-T-cell receptor (TCR) idiotypic antibodies in RSA patients. The sera of these patients were assessed for inhibitory activity against mixed lymphocyte reactions (MLR) between maternal responder cells and paternal stimulator cells. Sera of four of the five women who maintained pregnancy successfully after immunotherapy showed significant MLR inhibition, whereas none of the five women who had unsuccessful pregnancies showed significant MLR inhibition. These sera inhibited the MLR of autologous responder T-cells, when stimulated with lymphocytes having the same HLA-DR antigens as the patient's husband, but not when stimulated with lymphocytes having unrelated HLA-DR antigens. This MLR inhibitory activity was absorbed by autologous maternal T-lymphoblasts induced by stimulation with lymphocytes having the paternal HLA-DR type but not by those induced by stimulation with lymphocytes having other HLA-DR types. The maternal serum inhibited the proliferation of autologous T-cells, but not of non-autologous T-cells, stimulated with paternal lymphocytes. These results indicate that anti-TCR idiotypic antibodies were induced in RSA patients by immunotherapy. These antibodies may contribute to maintaining pregnancy by negatively regulating maternal T-cells directed against HLA-DR antigens of the fetus.     

血清TNF-α及sHLA-G水平与习惯性流产的关联性分析

目的通过定量方法研究测定习惯性流产（RSA）患者血清中的肿瘤坏死因子-α（TNF-α）及可溶性人白细胞抗原G（sHLA-G）的水平,探讨TNF-α及sHLA-G与习惯性流产有无相关性。方法选择早期妊娠孕妇100例,正常对照组：无自然流产史早期妊娠健康孕妇42例,RSA组：有习惯性流产史二次及二次以上的早期妊娠妇女58例,采用酶联免疫（ELISA）法定量检测两组样本血清中TNF-α及sHLA-G的水平。结果 RSA组血清中外周血淋巴细胞的TNF-α表达水平则明显高于正常妊娠组差异有显著性（P〈0.05）,而sHLA-G的表达水平明显低于正常对照组,差异有显著性（P〈0.05）。结论妊娠早期孕妇血清中TNF-α及sHLA-G与妊娠成功有直接关系,TNF-α升高及sHLA-G降低可能会导致习惯性流产的发生。     

Immunoregulatory activity of decidua in spontaneous early pregnancy loss.

The present study aimed to address whether the immunoregulatory properties of the molecules secreted within decidua were altered in women suffering spontaneous miscarriage, compared with apparently normal fertile women. Unfractionated decidual cells from 22 women undergoing therapeutic pregnancy terminations and 25 women experiencing a sporadic spontaneous early pregnancy loss were isolated, cultured for 24 h and 72 h, and supernatants were collected. The effect of decidual supernatants on phytohaemagglutinin (PHA)-induced peripheral blood lymphocyte proliferation was investigated. Immunosuppressive activity was detected in 24 h cell culture supernatants from 91% of therapeutic abortion cases compared with only 64% of spontaneous abortion samples; 72 h supernatants from all of therapeutic abortion samples and 90% of spontaneous abortion cases suppressed lymphoproliferation. The remaining spontaneous abortion samples (36% of 24 h supernatants; 10% of 72 h supernatants) enhanced or had no effect on lymphocyte proliferation. Enhancement of lymphocyte proliferation was not observed in therapeutic abortion samples, and the association between stimulation of cell proliferation and spontaneous abortion was significant for 24 h decidual cell supernatants at 50% concentration (P = 0.02). These findings suggest that in a subgroup of women experiencing spontaneous early pregnancy loss, soluble factors within decidua display altered immune responses that may be implicated in the complex process of fetal rejection.     

Leukocyte activation in the decidua of chromosomally normal and abnormal fetuses from women with recurrent abortion

As part of our continuing programme to investigate immunological causes of unexplained recurrent pregnancy losses, we studied subpopulations of white blood cells and their activation status in decidua of women with a history of recurrent spontaneous abortion (RSA). We differentiated specifically between normal karyotyped male fetuses and abnormal karyotyped fetuses with trisomy 16 because trisomy 16 is not compatible with life and is thus a non-controversial cause of spontaneous miscarriage. Leukocytes were counted in paraffin-embedded decidua after immunohistological staining for CD45 (LCA), CD3, CD56, CD68, CD69 and CD25. Numbers of activated versus non-activated T lymphocytes, NK cells and macrophages were compared in decidua from women with: (i) unexplained RSA who had a normal male karyotype (n = 17) miscarriage; (ii) unexplained RSA who had a trisomy 16 (n = 21) miscarriage; and (iii) normal gestationally age-matched first trimester pregnancies following elective termination procedures (n = 20). Significantly more activated leukocytes were detected in the decidua of women with unexplained RSA who had a normal male karyotype compared to the other groups (P < 0.0001). In addition, numbers of cells comprising the major leukocyte subpopulation, CD56+ NK cells, appeared reduced in the decidua of women with unexplained RSA compared to decidua from women having elective terminations. Increased numbers of activated leukocytes in the decidua of women with a history of unexplained recurrent pregnancy loss who had a normal karyotyped pregnancy provide evidence that cellular immunity may be involved in unexplained recurrent pregnancy loss.     

Blocking antibodies in blood from patients with recurrent spontaneous abortion in relation to pregnancy outcome and intravenous immunoglobulin treatment

PROBLEM: To study whether the occurrence of mixed lymphocyte culture (MLC) blocking antibodies is associated with pregnancy outcome in women with unexplained recurrent spontaneous abortion (RSA) and the in vivo effect of intravenous immunoglobulin (IVIG) treatment on MLC blocking effect. METHOD OF STUDY: Blood samples from 41 RSA patients were obtained before and after pregnancy, and blocking antibodies were estimated by one-way MLC assay. The patients received IVIG or placebo (saline) during pregnancy. Additionally, prepregnancy blood samples from 31 RSA women and 10 controls were obtained. RESULTS: We found no correlation between blocking antibodies before pregnancy and the pregnancy outcome. The occurrence of blocking antibodies was not affected by pregnancy or IVIG treatment. CONCLUSIONS: Blocking antibodies have no predictive value for the pregnancy outcome in RSA patients, and their production seems not to be affected by IVIG.     

Expression of kisspeptin/GPR54 and PIBF/PR in the first trimester trophoblast and decidua of women with recurrent spontaneous abortion

Kisspeptin and its receptor GPR54 play a major role in trophoblast invasion, and progesterone-induced blocking factor (PIBF) is needed for maintaining pregnancy. The expression of kisspeptin/GPR54 and PIBF/progesterone receptor (PR) in trophoblasts and deciduas and the relationship between kisspeptin and PIBF were investigated in the same women with recurrent spontaneous abortion (RSA). Trophoblastic and decidual tissues were collected from 32 RSA women who miscarried a genetically normal fetus, and 35 women who had voluntary abortion. Kisspeptin, GPR54, PIBF and PR were investigated using immunohistochemistry. Kisspeptin, GPR54 and PIBF expressions in syncytiotrophoblasts and cytotrophoblasts were decreased in RSA women as compared to controls (P < 0.05). Kisspeptin, PIBF and PR expressions in deciduas were significantly decreased in RSA women as compared to controls (P < 0.01). GPR54 expression in deciduas nearly showed no difference between the RSA group and the control group (P = 0.958). Kisspeptin and PIBF expressions in syncytiotrophoblasts, cytotrophoblasts and deciduas were correlated with each other in the RSA group (Kappa = 0.602, P = 0.001; Kappa = 0.590, P = 0.001; Kappa = 0.392, P = 0.011). These data support the hypothesis that decreased kisspeptin and PIBF expressions in trophoblasts and deciduas are associated with RSA.     

T and B lymphocyte subsets in patients with unexplained recurrent spontaneous abortion: IVIG versus placebo treatment

PROBLEM: To investigate circulating lymphocyte subsets in women with recurrent spontaneous abortion (RSA) in relation to pregnancy outcome and to treatment with intravenous immunoglobulin (IVIG). METHOD OF STUDY: Forty-one women with a history of unexplained RSA were examined during first trimester of pregnancy before IVIG or placebo treatment and after pregnancy. The results were compared with five healthy, non-pregnant women and five women in the first trimester of normal pregnancy. Circulating lymphocyte subsets with focus on T-cell subpopulations were determined by flow cytometry. RESULTS: The proportions of human leukocyte antigen (HLA)-DR positive T cells (CD3+ HLA-DR+), T-killer/effector cells (CD8+ S6F1+) and B cells (CD19+) were increased, whereas the proportion of T-suppressor/inducer cells (CD4+ CD45RA+) was decreased during first trimester pregnancy of RSA women compared with pregnant normal controls. T and B lymphocyte subsets did not correlate with pregnancy outcome on either IVIG or placebo group. CONCLUSIONS: In RSA patients, the immune system seems to be activated in contrast to the suppression noted in normal pregnancy.