Natural Killer Cells In Women Research Articles

Evaluation of the effectiveness of third-generation lipid emulsion therapy for early pregnancy loss

BACKGROUND: Immune mechanisms play an important role in the pathogenesis of early pregnancy loss. To regulate disorders of immune homeostasis, immunoefferent therapy is used, such as immunocytotherapy, plasmapheresis, and intravenous administration of immunoglobulins and lipid emulsions, which may help to overcome infertility and recurrent miscarriage. Third-generation lipid emulsion (TGLE) is the modern “gold standard” of parenteral lipid therapy. It contains high concentrations of omega-3-polyunsaturated fatty acids, which can directly or indirectly affect the activity of natural killer (NK) cells. The literature comprises contradictory data on the efficacy of TGLE for repeated implantation failure. This may be due to the determination of biochemical parameters for its use and the selection of criteria for assessing the effectiveness of this therapy.
 AIM: The aim of this study was to evaluate the effectiveness of TGLE therapy in patients with a history of early pregnancy loss.
 MATERIALS AND METHODS: This prospective randomized controlled study enrolled 140 patients with early pregnancy loss (recurrent miscarriage and repeated implantation failure) at the Research Institute of Obstetrics, Gynecology and Reproducto logy named after D.O. Ott, Saint Petersburg, Russia from 2021 to 2023. Group 1 consisted of 50 women with TGLE therapy, and group 2 included 90 women without therapy. Patients of group 1 received lipid therapy according to the following regimen: TGLE 20% IV 6 ml per kilogram of body weight once a month for two months on end. Inclusion criteria: women from 18 to 45 years of age with two cases of reproductive failure – pregnancy loss up to 12 weeks of gestation and/or unsuccessful in vitro fertilization attempts (embryo transfers without effect) with normal karyotypes of the spouses. Exclusion criteria: women with miscarriage with an abnormal karyotype of the fetus, with anatomical abnormalities in the development of the reproductive apparatus, with an abnormal karyotype of any of the spouses, with hypersensitivity to omega-3 polyunsaturated fatty acids. We assessed the omega-3 index, functional characteristics of NK cells in the peripheral blood, and the effectiveness of lipid therapy based on biochemical and immunological parameters, as well as the clinical onset of pregnancy.
 RESULTS: The difference in the omega-3 index before and after treatment with TGLE was significant (p = 0.0002), this parameter being increased by 1.23 times compared to the initial level. The functional activity of NK cells in the blood was significantly different after the administration of TGLE: NK (CD3–CD(16+56+)) (p = 0.0041), NKT (CD3+CD(16+56+)) (p = 0.0498), and spontaneously activated NK (CD107a) (p = 0.0498). These parameters decreased by 1.63, 1.29, and 2.07 times relative to their initial levels. In group 1 of patients receiving TGLE therapy, clinical pregnancy occurred twice as often as compared to those who did not receive this therapy (56.41%, n = 22 vs. 31.25%, n = 20; p = 0.01).
 CONCLUSIONS: TGLE has shown effectiveness in pregnancy rates by increasing the omega-3 index and reducing the functional activity of NK cells in women with early pregnancy loss.

PREDICTION AND DIAGNOSIS OF REPRODUCTIVE FAILURES BASED ON NKp46 EXPRESSION IN ENDOMETRIAL OR DECIDUAL NK CELLS

Natural Killer (NK) cells are the most abundant immune cells at the time of implantation and early stage of pregnancy in uterine endometrium and decidua. NK cells have important roles in the achievement and maintenance of pregnancy. NKp46, an NK cell receptor, is involved in cytotoxicity and cytokine production. We have previously reported the lower expression of NKp46 on uterine and peripheral blood NK cells in women with reproductive failures, such as repeated implantation failures or recurrent pregnancy loss (RPL).

Diagnostic significance of assessing peripheral natural killer cells in women with recurrent pregnancy loss

Aim: to assess peripheral blood NK cell (pNK) counts in women with recurrent pregnancy loss.Materials and Methods. There were examined 102 women: 28 non-pregnant (immediately after repeatedly terminated pregnancy, group IA) and 34 pregnant women with history of previous recurrent pregnancy loss (group IB). Control and comparison groups were consisted of healthy women lacking any recorded miscarriage: 20 non-pregnant (group IIA) and 20 pregnant women (group IIB), respectively. Along with assessing complete blood count range, all subjects were analyzed percentage of pNK cell CD16bright(+) CD56dim(-) cytotoxic phenotype by using fluorescence microscopy as well as level of cytokines IL-2, IL-6, IL-10, tumor necrosis factor (TNF-α), vascular endothelial growth factor (VEGF) and interferon-gamma (IFN-γ) using ELISA.Results. It was found that the level of NK cell cytotoxic phenotype - percentage of CD16+CD56- was elevated in both groups: groups: group IA - 36.5 % collared with the control group IIA - 27.5% (р < 0.05); in group IB up to 37.0 %, in comparison group IIB - 27.4% (р < 0.01). It was further corroborated by increased level of serum cytokine IL-6 IL-6 comprising in group IA vs. IIA - 28.5 pg/ml vs. 14.2 pg/ml (р < 0.01) as well as in group IB vs. IIB up to 16.7 pg/ml vs. 12.2 pg/ml (р < 0.01), respectively. However, level of serum IL-2 and IL-10 did not significantly differ in all groups examined. Interestingly, level of VEGF in subjects aged 21-30 years was elevated: in non-pregnant (group IA) vs. control (group IIA) - up to 548.5 pg/ml vs. 310.8 pg/ml (р < 0.01); pregnant women (IB) vs. comparison group (IIB) - insignificantly elevated up to 476.1 pg/ml vs. 381.5 pg/ml, respectively. In contrast, no significant changes were observed in 31-40-year group. Concentration of IFN-γ in group IA vs. control group (IIA) was increased up to 9.2 pg/ml vs.8.64 pg/ml; group IB vs. comparison group - up to 8.36 pg/ml vs. 7.56 pg/ml, respectively.Conclusion. Elevated percentage of cytotoxic CD16+CD56- NK cells in peripheral blood results in imbalance of immune-related parameters that directly correlated with increased serum level of IL-2, IL-6, TNF-α that may alter maternal immune tolerance to the fetus and subsequently resulting in recurrent pregnancy loss. Hence, the aforementioned data may be used as diagnostic and prognostic criteria in recurrent pregnancy losses.

Expression of natural cytotoxicity receptor NKp46 on peripheral blood natural killer cells in women with a history of recurrent implantation failures.

The peripheral blood natural killer (NK) cells diversity is highly complex; recent studies described more than a thousand phenotypes sharing NK cell receptors, across the leukocyte lineages. In this study, we investigated the expression of NKp46 in peripheral blood NK cells in women with a history of recurrent implantation failures (RIF) with euploid embryos with pre-implantation genetic diagnosis (PGD) and control group (donors of oocytes and surrogate mothers). The expression of NKp46 in peripheral blood lymphocytes and NK cells from women with RIF (n = 57) and control group (n = 50) was analyzed with three-color flow cytometry. The percentage of NKp46+ NK cells was significantly higher in women with RIF compare with the control group and high amount of NKp46+ NK cells (>13% of total lymphocytes) was a poor prognostic factor for embryo implantation. Also, women with RIF had a low amount of NKp46neg NK cells, which was a negative prognostic factor for embryo implantation. The analysis of NK subpopulations, on the basis of NKp46 expression, also revealed that NKp46neg NK in low amounts (<20% of NK cells) and NKp46dim in high amounts (>50% of NK cells) are also negative prognostic factors for embryo implantation. Our results support the clinical significance of the NKp46 expression on NK cells in women with RIF. We suggest that the low level of NKp46neg subset in women with RIF may be a result of an imbalance in the differential development of ILC subsets toward cytotoxic ILC (NK cells), which in turn is a negative condition for successful embryo implantation.

Endometrial CD56+ natural killer cells in women with recurrent implantation failure: An immunohistochemical study.

Objective:Implantation failure is a multifactorial problem of reproductive medicine. However, the mechanism of this process is still not fully understood. There is increasing evidence that these cases of recurrent implantation failure might have an immunologic background. Uterine natural killer (NK) cells provide immune-modulation at the interface between maternal decidua and the trophoblast. The aim of this study to evaluate whether there was a significant difference in the number of endometrial CD56+ NK between women with a history of recurrent implantation failure and women who had a live birth.Materials and Methods:Patients with a history of recurrent implantation failure were included in the study. Twenty-five women with a history of recurrent implantation failure were assigned to the case group, and 25 women who had one or more live births were assigned to the control group. Endometrial biopsies were obtained during the luteal phase on the 21st-24th day of the menstrual cycle.Results:There was a statistically significant difference between the groups concerning the number of deliveries (p<0.001) and miscarriages (p<0.001). The mean number of uNK was 10.5±10.5 cells/mm2 in the case group and 19.2±11.2 cells/mm2 in the control group. There was a statistically significant difference between the two groups (p=0.003).Conclusion:Implantation failure is a multifactorial problem of reproductive medicine. The results of our study suggest that uterine NK play a role in the progress of normal pregnancy and reduced uterine NK cell numbers were associated with implantation failure.

A semen-based stimulation method to analyze cytokine production by uterine CD56bright natural killer cells in women with recurrent pregnancy loss

Cytokine secretion by NK cells is abnormal in some women with recurrent pregnancy loss (RPL). Cytokine production is usually evaluated after stimulation with PMA and ionomycin. However, stimulation of uterine NK cells with semen corresponds more closely to physiological conditions at the time of conception. As seminal plasma has immunomodulatory properties, we aimed to elucidate compatibility between uterine NK cells and semen. Endometrial samples were stimulated with PMA/ionomycin, semen, seminal plasma, or spermatozoa. Thereafter, cytokine production by NK (CD56bright) cells was evaluated using flow cytometry and compared between women with and without a history of RPL associated with abnormal NK cell distribution in the endometrium or unexplained RPL. The ratios (%) of NK cells producing IFN-γ and TNF-α (NK1 phenotype), IL-4 (NK1/NK2 phenotype), and IL-10 (NK1/NKr1 phenotype) were significantly lower after stimulation with semen than with PMA/ionomycin (P < 0.01). After exposure to semen, ratios (%) of NK cells producing IL-4 and IL-10 in patients with unexplained RPL were significantly lower (P < 0.05), whereas those of NK1/NK2 and NK1/NKr1 were significantly higher (P < 0.01) than those in controls. The shift of endometrial NK cells to the NK2 phenotype was more pronounced when stimulated by semen than by PMA/ionomycin. However, a semen-induced shift to NK1 in women with unexplained RPL could induce miscarriage. Couple-specific immunological compatibility tests through semen stimulation in vitro might provide important information to avoid RPL.

A Plate-based Cytotoxicity Assay for the Assessment of Rat Placental Natural Killer Cell Cytolytic Function.

It is well known that decidual natural killer (NK) cells play a critical role in establishment and maintenance of normal pregnancy. Recent studies have demonstrated an altered population of circulating and decidual NK cells in women who suffer from adverse pregnancy complications such as recurrent miscarriage and preeclampsia. Studies from our group have shown that hypertension in pregnancy is associated with an increased population of activated NK cells in the placenta based on the expression of surface activation markers. This manuscript provides a detailed protocol to assess the cytotoxic function of NK cells isolated from placentas in a preeclampsia-like animal model of surgically induced placental ischemia. The following steps are described in detail: generation of single cell suspension, NK cell isolation, ex vivo stimulation, effector:target cell co-culture, and the cytotoxicity assay.

The number and cytotoxicity and the expression of cytotoxicity-related molecules in peripheral natural killer (NK) cells do not predict the repeated implantation failure (RIF) for the in vitro fertilization patients

Natural killer (NK) cells are thought to play a key role in the successful establishment of a pregnancy by facilitating immunological adaptation of the semi-allogeneic developing embryo. The aim of this study was to explore the cell number, immunophenotypic characteristics, and activities of peripheral blood NK cells in women with repeated implantation failure (RIF). Peripheral blood was obtained from 27 women with RIF and 11 healthy, fertile controls during the middle luteal phase of the menstrual cycle. CD3- CD56+ NK cells were quantified and analyzed by flow cytometry for the expression of cytolytic molecules (granzyme B, granulysin, and perforin) as well as cell surface receptors responsible for NK cell activation or inhibition (NKG2D, NKp30, NKp46, CD158a, CD158b). NK cytotoxicity was measured at three effector-to-target cell ratios. Women with RIF and fertile controls did not differ significantly in the percentage of circulating CD3−CD56+ NK cells, or in the proportions of these cells that expressed granzyme B, granulysin, or perforin. The two groups also did not differ significantly in the proportions of NK cells expressing the receptors NKG2D, NKp30, NKp46, CD158a or CD158b. General linear model analysis showed that NK cytotoxicity increased with effector-to-target cell ratio. However, NK cytotoxicity did not differ significantly between patients with RIF and fertile controls. These results suggest that RIF is not associated with significant alterations in the number or function of peripheral blood NK cells.

Analysis of cytotoxic activity of peripheral blood natural killer cells in women with recurrent miscarriage

Analysis of cytotoxic activity of peripheral blood natural killer cells in women with recurrent miscarriage

The crosstalk between endometrial stromal cells and macrophages impairs cytotoxicity of NK cells in endometriosis by secreting IL-10 and TGF-β.

The dysfunction of NK cells in women with endometriosis (EMS) contributes to the immune escape of menstrual endometrial fragments refluxed into the peritoneal cavity. The reciprocal communications between endometrial stromal cells (ESCs) and lymphocytes facilitate the development of EMS. However, the mechanism of these communications on cytotoxicity of natural killer (NK) cells in endometriotic milieus is still largely unknown. To imitate the local immune microenvironment, the co-culture systems of ESCs from patients with EMS and monocyte-derived macrophages or of ESCs, macrophages and NK cells were constructed. The cytokine levels in the co-culture unit were evaluated by ELISA. The expression of functional molecules in NK cells was detected by flow cytometry (FCM). The NK cell behaviors in vitro were analyzed by cell counting kit-8 and cytotoxic activation assays. After incubation with ESCs and macrophages, the expression of CD16, NKG2D, perforin and IFN-γ, viability and cytotoxicity of NK cells were significantly downregulated. The secretion of interleukin (IL)-1β, IL-10 and transforming growth factor (TGF)-β in the co-culture system of ESCs and macrophages was increased. Exposure with anti-IL-10 receptor β neutralizing antibody (αhIL-10Rβ) or αTGF-β could partly reverse these effects of ESCs and macrophages on NK cells in vitro These results suggest that the interaction between macrophages and ESCs downregulates cytotoxicity of NK cells possibly by stimulating the secretion of IL-10 and TGF-β, and may further trigger the immune escape of ectopic fragments and promote the occurrence and the development of EMS.

An endometrial histomorphometric study of CD56+ natural killer cells in women with unexplained infertility

Background . The number of peripheral blood and endometrial natural killer cells varies greatly during implantation and the first trimester of pregnancy and is thought to play a role in the maintenance of a healthy pregnancy. However, the role of endometrial CD56+ natural killer (NK) cells as an immunological mechanism in unexplained infertility is yet unknown. Objectives. The study aimed to enumerate the concentrations of CD56 + NK cells in endometrial samples, and to statistically compare these numbers between fertile and infertile women. Methods . A histomorphometric analysis was conducted using haematoxylin and eosin staining and an immunohistochemical approach was used for quantifying cell numbers. Results . Fifty samples were collected in equal parts between a study group of infertile female subjects (mean (standard deviation) age 35 (4), range 26 - 42 years) and a control group of multiparous fertile individuals (mean (SD) age 43.4 (6.3), range 30 - 55). The mean number of CD56+ NK cells present at different depths for both the study and control groups did not differ significantly. Age and group (study or control) were not significantly related to the mean number of CD56+ NK cells. However, for the late secretory phase the mean number of CD56+ NK cells was significantly higherthan for the early phase. Conclusion. Our findings could not identify a statistically significant correlation between the number of CD56 + NK cells and infertility.

Expression of natural cytotoxicity receptors and cytokine production on endometrial natural killer cells in women with recurrent pregnancy loss or implantation failure, and the expression of natural cytotoxicity receptors on peripheral blood natural killer cells in pregnant women with a history of recurrent pregnancy loss.

Natural cytotoxicity receptors (NCR) are unique markers that regulate natural killer (NK) cell cytotoxicity and cytokine production. In this study, we investigated the expression of NCR (NKp46, NKp44, and NKp30) and cytokine production in NK cells derived from the uterine endometrium of women with recurrent pregnancy loss (RPL). We also investigated the expression of NCR in peripheral blood NK cells in pregnant women with and without a history of RPL. The expression of NCR (NKp46, NKp44, and NKp30) in NK cells (CD56dim and CD56bright ) in the uterine endometrium was analyzed using 3-color flow cytometry. Cytokine (tumor necrosis factor-α and interferon-γ) production was also analyzed. NK cells from the mid-secretory endometrium of 28 women with RPL, 34 women with implantation failure, and 74 controls were collected and mechanically dispersed using a tissue grinder. The expression of NCR in peripheral blood NK cells from pregnant women with (n = 17) and without (n = 91) a history of RPL was analyzed. The percentages of NKp46+ NK cells were significantly lower in both women with RPL and pregnant women with a history of RPL. The percentages of tumor necrosis factor-α- and/or interferon-γ-producing uterine endometrial NK cells were significantly lower in women with RPL compared with controls. The changes in NCR expression and cytokine production, especially decreased NKp46 expression in endometrial NK cells, suggests the presence of abnormal NK cell regulation in women with reproductive failures.

Platelet-derived TGF-β1 mediates the down-modulation of NKG2D expression and may be responsible for impaired natural killer (NK) cytotoxicity in women with endometriosis.

Does platelet-derived transforming growth factor-β1 (TGF-β1) have any role in the reduced cytotoxicity of natural killer (NK) cells in women with endometriosis? Platelet-derived TGF-β1 suppresses the expression of NK Group 2, Member D (NKG2D) on NK cells, resulting in reduced cytotoxicity in women with endometriosis, but neutralization of TGF-β1 reverses the reduction. NK cells are cytotoxic lymphocytes that play an important role in peritoneal immune surveillance, and their function is known to be impaired in women with endometriosis. There is increased platelet aggregation in endometriotic lesions and increased platelet activation rate in the peripheral blood in women with endometriosis, yet activated platelets release copiousTGF-β1, which is known to be a potent immunosuppressive molecule that suppresses NK cell function and NKG2D expression. Cross-sectional clinical studies of 30 women with endometriosis and 33 women without endometriosis and in vitro experimentation with and without TGF-β1 blockade. Peritoneal fluid (PF) samples from premenopausal women with endometriosis and age- and menstrual phase-matched controls were collected. Platelet count, white blood cell (WBC) count, mean platelet volume (MPV), platelet activation rate, TGF-β1 concentration, expression levels of NKG2D on NK cells in the PF were evaluated. The apoptosis of freshly isolated NK cells treated with PF from women with endometriosis, the NK cytotoxicity and NKG2D expression treated with PF in the presence or absence of an anti-TGF-β1 antibody were also determined. The platelet count, WBC count, MPV, platelet activation rate and the TGF-β1 concentration in the PF from women with endometriosis were significantly elevated when compared with those of women without endometriosis. The TGF-β1 concentration correlated positively with the platelet activation rate (r = 0.59, P < 0.01), suggesting that activated platelets are responsible, at least in part, for the increased TGF-β1 concentration. The cytotoxicity of freshly isolated NK cells treated with PF of women with endometriosis is significantly reduced when compared with that of women without endometriosis. Both the platelet activation rate and the TGF-β1 concentration in the PF correlated negatively with the NKG2D expression in NK cells isolated from the PF (r = -0.36, P < 0.01, and r = -0.45, P < 0.01, respectively). In addition, the NKG2D expression level and the cytotoxicity in freshly isolated NK cells were found to be significantly reduced if co-cultured with PF from women with endometriosis, but the TGF-β1 blockade effectively reverses the reduction. This study is limited by the cross-sectional nature of the study. NKG2D is known to potently activate NK cells, so potent that it even overrides inhibitory signals transduced by other inhibitory receptors. This is the first time we demonstrate that platelet-derived TGF-β1 may be responsible for reduced NKG2D expression as well as reduced cytotoxicity of NK cells in women with endometriosis. This study provides yet another piece of evidence that platelets play critical roles in the development of endometriosis, and anti-platelet treatment should improve NK cell functionality in treating endometriosis. Equally important, this study highlights the critical role of the lesion microenvironment in shaping NK cell-mediated anti-endometriotic immunity. This research was supported in part by grants 81270676 (S.-W.G.), 81471434 (S.-W.G.), 81530040 (S.-W.G.), and 81370695 (X.L.) from the National Natural Science Foundation of China, and grant 2013ZYJB0019 (X.L.) from Shanghai Municipal Commission of Health and Family Planning. None of the authors has anything to disclose.

Natural killer (NK) cell profiles in blood and tumour in women with large and locally advanced breast cancer (LLABC) and their contribution to a pathological complete response (PCR) in the tumour following neoadjuvant chemotherapy (NAC): differential restoration of blood profiles by NAC and surgery.

BackgroundNK cells contribute to tumour surveillance, inhibition of growth and dissemination by cytotoxicity, secretion of cytokines and interaction with immune cells. Their precise role in human breast cancer is unclear and the effect of therapy poorly studied. The purpose of our study was to characterise NK cells in women with large (≥3 cm) and locally advanced (T3–4, N1–2, M0) breast cancers (LLABCs) undergoing neoadjuvant chemotherapy (NAC) and surgery, and to ascertain their possible contribution to a pathological complete response (pCR).MethodsWomen with LLABCs (n = 25) and healthy female donors [HFDs (n = 10)] were studied. Pathological responses in the breast were assessed using established criteria. Blood samples were collected pre and post NAC and surgery. Flow cytometry and labelled monoclonal antibodies established absolute numbers (AbNs) and percentages (%) of NK cells, and expressing granzyme B/perforin and NKG2D. In vitro NK cytotoxicity was assessed and NK cells and cytokines (IL-2, INF-γ, TGF-β) documented in tumours using immunohistochemical techniques. Data was analysed by SPSS.ResultsWomen with LLABCs had significantly reduced AbNs (160.00 ± 40.00 cells/µl) but not % of NK cells, compared with HFDs (NK: 266.78 ± 55.00 cells/µl; p = 0.020). NAC enhanced the AbN (p = 0.001) and % (p = 0.006) of NK cells in patients with good pathological responses. Granzyme B+/perforin+ cells were significantly reduced (43.41 ± 4.00%), compared with HFDs (60.26 ± 7.00%; p = 0.003). NAC increased the % in good (p = 0.006) and poor (p = 0.005) pathological responders. Pretreatment NK cytotoxicity was significantly reduced in good (37.80 ± 8.05%) and poor (22.80 ± 7.97%) responders (p = 0.001) but remained unchanged following NAC. NK-NKG2D+ cells were unaltered and unaffected by NAC; NKG2D expression was increased in patients with a pCR (p = 0.001). Surgery following NAC was not beneficial, except in those with a pCR. Tumour-infiltrating NK cells were infrequent but increased peritumourally (p = 0.005) showing a significant correlation (p = 0.004) between CD56+ cells and grade of response. Tumour cytokines had no effect.ConclusionWomen with LLABCs have inhibited blood innate immunity, variably reversed by NAC (especially with tumour pCRs), which returned to pretreatment levels following surgery. These and in situ tumour findings suggest a role for NK cells in NAC-induced breast pCR.

Ultrastructure alteration of decidual natural killer cells in women with unexplained recurrent miscarriage: a possible association with impaired decidual vascular remodelling.

This study aimed to evaluate the extent of remodelling of intra-decidual segments of the spiral arteries in human deciduas between the 6th and 10th gestational weeks in women with unexplained recurrent miscarriages (RM) in comparison to gestational-matched controls. A possible association with the number, immunoexpressive behaviour and ultrastructural changes of decidual natural killer cells (dNKCs) was investigated. Decidual biopsies were obtained from RM cases (n = 40) and women with no history of spontaneous miscarriage and at least one live birth at term (n = 30). Staining was performed using PAS, anti-CD34 and anti-CD56 antibodies, using an avidin-biotin-peroxides technique. Analysis by means of light and transmission electron microscopy was employed. To determine the extent of remodelling of decidual vessels, a quantitative score was analysed using histological criteria of vascular transformation and then related to the number of CD56(+) dNKCs. In RM, dNKCs were distributed among decidual cells and around the vessels. They possessed numerous polyploidic protrusions on cell membranes crossing from one cell to another. The cells became more irregular and exhibited heterogeneous electron-dense granules in their cytoplasm compared to controls. The non-remodelling score and number of dNKCs were significantly increased in RM group (p < 0.001). The number of dNKCs was significantly correlated with the scores in both control (r = 0.491; p = 0.006) and RM (r = 0.852; p < 0.001) groups. It appears that dNKCs play a key role in impaired decidual artery remodelling that may be involved with early RM. This may be due to increased numbers of cells or impaired cellular interactions resulting from alterations to the ultrastructure.

Prolactin and natural killer cells: evaluating the neuroendocrine-immune axis in women with primary infertility and recurrent spontaneous abortion.

An association between serum prolactin (PRL) and peripheral blood natural killer (NK) cells has been described in healthy women. We explored for the first time the PRL response to the thyrotrophin-releasing hormone (TRH) test and the association between PRL and NK cells in women with reproductive failure. A total of 130 women [31 primary infertility, 69 recurrent spontaneous abortion (RSA), and 30 fertile women] were evaluated by a TRH test to analyze the following: basal PRL (bPRL), peak-time PRL, PRL absolute and relative increase, decline-time PRL. Hyperprolactinaemia (HPRL) was defined as bPRL ≥15ng/mL. NK cells were characterized by immunophenotyping. Significantly higher bPRL levels were found in the infertile women than in controls. Both the infertile and the RSA women showed significantly elevated NK levels. bPRL levels correlated with NK cells in HPRL-infertile women. In patients with HPRL, an association between NK cell and bPRL results. The dynamic test in the infertile women would help in the management of the pregnancy impairment.

Recurrent miscarriage is associated with a decline of decidual natural killer cells expressing killer cell immunoglobulin‐like receptors specific for human leukocyte antigen C

To investigate the relationship between natural killer (NK) cell phenotype and recurrent miscarriage (RM). We studied killer cell immunoglobulin-like receptor (KIR) expression on decidual NK cells in women with RM. The expression of KIR2DL1/S1 on CD56(+) CD16(-) NK cells in the deciduas of these women was significantly lower than in that of control subjects (P = 0.026). There was a significant decline in the frequency of CD56(+) CD16(-) NK cells staining for KIR2DL1/S1 and KIR2DL2/S2/L3 throughout the first trimester in patients (P < 0.05). Furthermore, by stratification of the women in three groups according to gestational stage, it was found that KIR2DL1/S1 expressing NK cells were significantly decreased in all groups, especially around gestational days 50-70 (P = 0.010). This is the first report to demonstrate that RM is associated with a decline in the frequency of decidual NK cells expressing KIR specific for human leukocyte antigen (HLA)-C, and in which gestational stage was considered. The results suggest that KIR phenotype contributes to the pathogenesis of the disease, and that assessment of KIR may serve as a diagnostic tool.

Characterization of endometrial natural killer cells in women with infertility or recurrent pregnancy loss and associated endometriosis

Endometrial natural killer cells (eNK) are the most abundant leukocyte population in the endometrium and have been thought to play a key role in the etiopathogenesis of endometriosis and reproductive disorders. CD56brightCD16- NK cells can produce angiogenic factors that promote spiral artery remodeling and cytokines (LIF, leukemia inhibitory factor) that direct the migration of trophoblasts. Their function is controlled by inhibitory receptors (NKG2a) and activating receptors (NKp46). CD16+ NK cells display cytotoxic activity towards trophoblasts and endometrial cells.

Impact of intravenous immunoglobulin on peripheral blood natural killer cells in women with recurrent spontaneous abortion

Objective To explore the impact of intravenous immunoglobulin on peripheral blood natural killer (NK) cells in women with recurrent spontaneous abortion (RSA).Methods Of 38 patients with RSA who had been hospitalized during the period of January 2011 to June 2012,18 patients received intravenous immunoglobulin (study group) while the rest 20 who refused to receive immunoglobulin were assigned to a control group.Peripheral NK cell cytotoxicity and rate of NK cells in all types of lymphocytes were detected before and after treatment by flow cytometry.Results NK cell cytotoxicity was(22.4 + 7.9)％ in the study group and (21.7 ± 8.1)％ in the control group before treatment,was (15.0 ± 4.2)％ in the study group and (25.6 ± 7.9)％ in the control group after treatment.Before treatment,the rate of NK cell was (25.1 ± 9.4) ％ in the study group and (24.0 ± 9.0) ％ in the control group,while after treatment it was (26.2 ± 8.7) ％ in the study group and (23.6 ± 6.8) ％ in the control group.NK cell c.vtotoxicity but not the rate of NK cell was significantly reduced (P＜0.05) in the study group.After treatment,NK cell cytotoxicity and the rate of NK cell did not differ significantly (P＞0.05).88.9％ of the patients in the study group but 55.0％ of the patients in the control group had pregnancy duration of longer than 24 weeks after tocolytic treatment (P＜0.05).Conclusions Intravenous immunoglobulin can reduce NK cell cytotoxicity,leading to an increase in the success rate of miscarriage prevention in patients with recurrent spontaneous abortion. Key words: Recurrent spontaneous abortion; Intravenous immunoglobulin; Natural killer cells

Detailed analysis of peripheral blood natural killer cells in women with repeated IVF failure

Detailed analysis of peripheral blood natural killer cells in women with repeated IVF failure