The Effects of LIT and MLR-Bf on Immune Biomarkers and Pregnancy Outcomes in Women With Previous Early Recurrent Miscarriage: A Retrospective Study

Background: Immunological failure during pregnancy is considered one of the etiologies of recurrent miscarriage (RM). The decreased production of mixed lymphocyte reaction-blocking factors (MLR-Bf) may play a major role in this condition. Lymphocyte immunotherapy (LIT), which induces the production of MLR-Bf, has been used in treating RM patients since 1984. However, the effectiveness of LIT is currently being heatedly debated. In addition to that, possible changes to the maternal immune system upon induced MLR-Bf production by LIT remains unclear. Objectives: To explore the possible impacts that MLR-Bf may have on the expression of immune biomarkers and pregnancy outcomes, and deduce whether the prevention of miscarriages is possible with LIT or MLR-Bf in RM patients. Materials and Methods: Women with previous early RM (eRM) were enrolled in this retrospective study after they got pregnant again. LIT was implemented before pregnancy and during the first trimester. MLR-Bf and immune biomarkers were checked as the clinical routine. Patients were followed up until 12 gestational weeks. Levels of immune biomarkers and successful pregnancy rates were compared between MLR-Bf^- group and MLR-Bf⁺ group stratified by LIT. Independent associations between LIT, or MLR-Bf, and miscarriage were estimated. All data management and analysis were conducted using SPSS 20.0. Results: A total of 1,038 patients, 497 MLR-Bf^- (49 cases accepted LIT), and 541 MLR-Bf⁺(463 cases induced by LIT) were included in the study. Percentage of lymphocytes, the ratio of CD4+ T cells/lymphocytes, and levels of some rheumatoid biomarkers (anti-U1-nRNP, anti-SAA-52kd, and anti-CENOP B) were statistically higher in MLR-Bf⁺ group than in MLR-Bf^- group among women without LIT. With LIT treatment the successful pregnancy rate was statistically higher in MLR-Bf⁺ group than in MLR-Bf^- group (66.7% vs. 51.0%, P = 0.028) among women with LIT. Meanwhile, LIT was estimated to have an independent negative association with miscarriage. Conclusion: Upon LIT treament levels of immune biomarkers were different in women with and without MLR-Bf when stratified by whether they received LIT. Not MLR-Bf, but LIT, has an independent protective effect on miscarriage.

Association of CD200 expression in paternal lymphocytes with female Th1/Th2 balance and pregnancy establishment at immunotherapy of recurrent spontaneous abortion

PROBLEM

We hypothesized that expression of transmembrane glycoprotein CD200 on paternal lymphocytes used for pre-gestational lymphocyte immunotherapy (LIT) of recurrent spontaneous abortion (RSA) can suppress the pro-inflammatory Th1-type immunity required for successful implantation. To reveal the association between CD200 expression, female immune background after LIT, and pregnancy establishment, we have performed this work.

METHOD OF STUDY

Pre-gestational alloimmunizations were given to 37 women using paternal peripheral blood leukocytes, combined with additional alloimmunizations in case of pregnancy. Lymphocyte phenotypes were determined by flow cytometry. Cytokines produced by mitogen-stimulated female peripheral blood cells were estimated by FlowCytomix™ technology.

RESULTS

We have shown that 78.4% (29/37) of women became pregnant within 12 menstrual cycles after pre-gestational LIT. Pregnancy establishment depends on the intensity of CD200 expression, which is significantly higher on the CD200⁺ lymphocytes administered to women who later did not achieve pregnancy (P < .05). The expression of CD200 negatively correlates with the ratios of Th1/Th2 cytokines produced by female peripheral blood cells (P < .05) and positively correlates with the frequency of female circulating regulatory T cells after LIT (P < .05). The ROC analysis showed that the intensity of CD200 expression and the Th1/Th2 ratios are the significant predictors of pregnancy establishment after pre-gestational LIT (P < .05 and P < .01, respectively).

CONCLUSION

Elevated CD200 expression on allogeneic lymphocytes most likely suppresses the pro-inflammatory Th1-type immunity needed for successful embryo implantation. Therefore, a personalized approach of LIT should be applied to avoid negative effects of such immunomodulation on pregnancy establishment.

Functional significance of lymphocytes in pregnancy and lymphocyte immunotherapy in infertility: A comprehensive review and update

During pregnancy, the fetal-maternal interface underlies several dynamic alterations to permit the fetus to be cultivated and developed in the uterus, in spite of being identifies by the maternal immune system. A large variety of decidual leukocyte populations, including natural killer cells, NKT cells, innate lymphoid cells, dendritic cells, B cells, T cells, subpopulations of helper T cells play a vital role in controlling the trophoblast invasion, angiogenesis as well as vascular remodeling. In contrast, several regulatory immunosuppressive mechanisms, including regulatory T cells, regulatory B cells, several cytokines and mediators are involved in maintain the homeostasis of immune system in the fetal-maternal interface. Nonetheless, aberrant alterations in the balance of immune inflammatory or immunosuppressive arms have been associated with various pregnancy losses and infertilities. As a result, numerous strategies have been developed to revers dysregulated balance of immune players to increase the chance of successful pregnancy. Lymphocyte immunotherapy has been developed through utilization of peripheral white blood cells of the husband or others and administered into the mother to confer an immune tolerance for embryo's antigens. However, the results have not always been promising, implying to further investigations to improve the approach. This review attempts to clarify the involvement of lymphocytes in contributing to the pregnancy outcome and the potential of lymphocyte immunotherapy in treatment of infertilities with dysregulated immune system basis.

Expression of Early Activation Marker CD69 on Peripheral Blood Lymphocytes from Pregnant Women after First Trimester Alloimmunization

We studied the expression of an early activation marker CD69 in peripheral blood lymphocytes of pregnant women with a history of recurrent pregnancy loss after immunization with paternal lymphocytes. Spontaneous and phytohemagglutinin-stimulated expression of CD69 on the surface of T cells and NK cells isolated from the peripheral blood was analyzed. On gestation week 5-6, the number of T cells expressing CD69 spontaneously and after stimulation was significantly higher in women with miscarriage than in woman with prolonged pregnancy. However, the number of cells with CD56(+) phenotype expressing CD69 did not differ in these groups. No differences were found in the number of cells of all subpopulations expressing CD69 after stimulation on gestation week 12 in woman with full-term current pregnancy and in woman with physiological pregnancy.

Mixed lymphocyte reaction blocking factors (MLR-Bf) as potential biomarker for indication and efficacy of paternal lymphocyte immunization in recurrent spontaneous abortion

OBJECTIVES

The majority of cases of unexplained recurrent spontaneous abortion (RSA) remains unclear and is found to be associated with alloimmune antibodies termed as mixed lymphocyte reaction blocking factor (MLR-Bf). The decreased production of MLR-Bf may play major role in the immunologic failure of pregnancy and can lead to abortion. The present study was aimed at evaluating MLR-Bf as potential biomarker of indication and the efficacy of immunotherapy with paternal lymphocytes (LIT) in women with RSA.

MATERIALS AND METHODS

A total of 97 women with history of unexplained RSA were recruited for this prospective study. These women showed negative for MLR-Bf and registered for lymphocyte immunotherapy with husband cells. Women with autoimmune pathology or anti-phospholipid syndrome were excluded. All individuals gave their consent to participate in the study.

RESULTS

We have analyzed MLR proliferative response and MLR-Bf in nonpregnant women with history of RSA before and after LIT. Following LIT, the initially low MLR proliferative response was restored at 76.6 % of women, and MLR-Bf activity in blood serum could be detected in 74 % of women. The rate of successful pregnancy was shown to be significantly higher in women positive for MLR-Bf (50/72) as compared with the MLR-Bf negative women (7/25; χ (2) = 0.0003).

CONCLUSION

The data obtained demonstrate that LIT with the paternal lymphocytes in MLR-Bf negative women is accompanied by increased proliferative cell response to the paternal alloantigens and by enhanced production of soluble suppressor activity factors (MLR-Bf) that is associated with improved pregnancy outcome in women with history of RSA.

Identification of sex-determining region Y (SRY) in maternal plasma after paternal lymphocyte immunization: is it possible?

PROBLEM

Women treated with allogeneic immunization using paternal lymphocytes often request laboratory molecular tests using cell-free fetal DNA in maternal plasma. There is concern whether the treatment can interfere with its results. This study evaluated the applicability of fetal sex determination using fragments of sex-determining region Y (SRY) in the plasma of women submitted to paternal lymphocyte immunization.

METHOD OF STUDY

  Non-pregnant women blood samples were collected at two different moments: prior to paternal lymphocyte immunization and after three doses of the immunotherapy, in a prospective study. For women who became pregnant, another sample was collect during the first trimester. Amplification of the fragment of the Y chromosome (SRY) was performed using real-time PCR.

RESULTS

The SRY gene was not identified in any of the plasma samples of the 50 non-pregnant women submitted to paternal lymphocyte immunization at either of the two moments evaluated. For the 26 pregnant women, the results of the identification of sex -determining in maternal plasma were completely in agreement with the infant sex.

CONCLUSION

Paternal lymphocyte immunization does not affect the results of SRY fragment investigation in the plasma of women submitted to paternal lymphocyte immunization therapy.

Progesterone-mediated immunomodulation in pregnancy: its relevance to leukocyte immunotherapy of recurrent miscarriage

Progesterone is crucial for the establishment and maintenance of pregnancy. Progesterone-regulated genes in the pregnant uterus control the development of endometrial receptivity as well as recruitment and differentiation of decidual NK cells, which in turn act on angiogenesis and trophoblast invasion. The link between progesterone and the immune system is established by lymphocyte progesterone receptors expressed in peripheral blood gammadelta T cells of pregnant women and in peripheral NK cells. Regulation of lymphocyte progesterone receptors is activation related, thus efficient recognition of fetal antigens is a requirement for the initiation of progesterone-dependent immunoregulatory mechanisms. Several immunological effects of progesterone are mediated by progesterone-induced blocking factor--the product of a progesterone-induced gene in lymphocytes. One part of unexplained recurrent miscarriages might have an immunological etiology. Immunization of the mothers with paternal or third-party leukocytes aims to correct the misregulated antifetal immune response. There are, however, serious concerns about this treatment, including the lack of information about the mode of action and possible adverse effects of the treatment, the failure to detect a significant effect of immunotherapy and the lack of a reliable generally accepted marker for patient selection. These concerns will be discussed in this review.

Pregnancy outcome after preimplantation genetic screening or natural conception in couples with unexplained recurrent miscarriage: a systematic review of the best available evidence

The objective of this systematic review was to assess live birth rates and miscarriage rates after preimplantation genetic screening or natural conception for unexplained recurrent miscarriage. There were no randomized controlled trials or comparative studies found on this topic. Until data from randomized controlled trials become available, this review summarizes the best available evidence of the efficacy of preimplantation genetic screening vs. natural conception.

Recurrent miscarriage: current concepts in diagnosis and treatment

Although recurrent miscarriage (RM) affects only 1-3% of couples, it has a major influence on the wellbeing and psychosocial status of patients. Therefore, research into improved diagnosis and development of new treatment strategies is essential. In this review, we summarize current concepts on diagnosis and treatment in RM, drawing upon research reports and international guidelines to provide insights into the pathophysiology of pregnancy disrupted by repeated miscarriage. Anatomical malformations, infectious diseases, endocrine disorders, autoimmune defects as well as acquired and inherited thrombophilia are established risk factors in RM. In addition, our recent findings indicate an impact on miscarriage incidence of glycoproteins such as glycodelin, and nuclear hormone receptors such as the peroxisome proliferator-activated receptors (PPARs). Significantly reduced glycodelin expression is associated with miscarriage, whereas up-regulation of PPARs appears to compensate for either the activated immune response or the disturbed cytotrophoblast differentiation in RM patients. There is also evidence that circulating placental microparticles are increased in a subgroup of RM patients, indicating an acquired procoagulant state even outside pregnancy. Treatment strategies like aspirin and low molecular weight heparin (LMWH) are standard medications in RM, although only a few placebo-controlled trials have proven their benefit in respect to live birth rate. There is emerging evidence that new treatment options, including drugs like TNFalpha inhibitors and granulocyte colony-stimulating factor (G-CSF) might be beneficial in some cases of RM. However, larger clinical trials must be completed to further prove or disprove benefits of these drugs in the treatment of RM patients.