Massive intravenous immunoglobulin treatment in women with four or more recurrent spontaneous abortions of unexplained etiology: down-regulation of NK cell activity and subsets

Effects of Intravenous Immunoglobulins on Human Innate Immune Cells: Collegium Internationale Allergologicum Update 2024

BACKGROUND

Intravenous immunoglobulin (IVIg) has been used for almost 40 years in the treatment of autoimmune and systemic inflammatory diseases. Numerous cells are involved in the innate immune response, including monocytes/macrophages, neutrophils, dendritic cells, mast cells, basophils, eosinophils, natural killer cells, and innate lymphoid cells. Many studies have investigated the mechanisms by which IVIg down-modulates inflammatory and autoimmune processes of innate immune cells. However, questions remain regarding the precise mechanism of action in autoimmune or inflammatory conditions. The aim of this work was to review the immunomodulatory effect of IVIg on only human innate immune cells. A narrative review approach was chosen to summarize key evidence on the immunomodulatory effects of commercially available and unmodified IVIg on human innate immune cells.

SUMMARY

Numerous different immunomodulatory effects of IVIg have been reported, with some very different effects depending on the immune cell type and disease. Several limitations of the different studies were identified. Of the 77 studies identified and reviewed, 29 (37.7%) dealt with autoimmune or inflammatory diseases. Otherwise, the immunomodulatory effects of IVIg were studied only in healthy donors using an in vitro experimental approach. Some of the documented effects showed disease-specific effects, such as in Kawasaki disease. Various methodological limitations have also been identified that may reduce the validity of some studies.

KEY MESSAGE

As further insights have been gained into the various inflammatory cascades activated in immunological diseases, interesting insights have also been gained into the mechanism of action of IVIg. We are still far from discovering all the immunomodulatory mechanisms of IVIg.

High doses of intravenous immunoglobulin stimulate regulatory T cell and suppress natural killer cell in women with recurrent pregnancy loss

The aim was to evaluate whether natural killer (NK) cells and regulatory T (Treg) cells were involved in mechanisms underlying beneficial effects of a high dose of intravenous immunoglobulin (IVIG) on recurrent pregnancy losses (RPL) of unexplained etiology. In a double-blind, randomized, placebo-controlled trial of IVIG (400 mg/kg, for 5 days in 4-6 weeks of gestation) in women with RPL, blood samples were collected pre-infusion, one week after infusion (1 w), and eight weeks of gestation/when miscarried (8 w). Levels of NK and Treg cells in peripheral blood were compared between women with IVIG (n = 50) and placebo (n = 49), and between women with IVIG who gave live birth (n = 29) and those who had miscarriage with normal chromosome (n = 12). Effector Treg cell percentages in IVIG group at 1 w (mean 1.43 % vs. 1.03 %) and at 8 w (1.91 % vs. 1.18 %) were higher than those in placebo group (p < 0.01). Total Treg cell percentages in IVIG group at 1 w (4.75 % vs. 4.08 %) and at 8 w (5.55 % vs. 4.47 %) were higher than those in placebo group (p < 0.05). In women with live birth, total Treg cell percentages increased at 8 w (5.52 %, p < 0.001) compared with pre-infusion (4.54 %) and 1 w (4.47 %), while NK cell activity decreased at 1 w (20.18 %, p < 0.001) compared with pre-infusion (26.59 %). IVIG increased Treg cell percentages and suppressed NK cell activity very early in pregnancy, and these were associated with subsequent live birth. Stimulation of Treg cells and suppression of NK cell activity very early in pregnancy may be a mechanism of pharmacological effects of high dose IVIG.

Peripheral blood natural killer cell cytotoxicity in recurrent miscarriage: a systematic review and meta-analysis

Dysregulated natural killer (NK) cells have been associated with recurrent miscarriages (RM). Studies have suggested that high peripheral blood NK cell cytotoxicities (pNKCs) are associated with an increased risk of RM. The aim of this systematic review (SR) and meta-analysis (MAs) is to investigate the difference in pNKC between nonpregnant and pregnant women with RM and controls and determine whether pNKC is reduced by immunotherapy. We searched the PubMed/Medline, Embase, and Web of Science databases. The MAs were conducted to compare pNKCs between women with and without RM before and during pregnancy as well as pre- and post-immunotherapy. Risk of bias in nonrandomized studies was assessed by the Newcastle-Ottawa Scale. Statistical analysis was performed using the Review Manager software. A total of 19 studies were included in the SR and 14 studies in the MAs. The MAs revealed higher pNKCs among nonpregnant women with RM compared to controls (MD, 7.99 95 %CI 6.40-9.58; p < 0.00001). pNKCs were also higher in pregnant women with RM than in pregnant controls (MD, 8.21 95 %CI 6.08-10.34; p < 0.00001). Women with RM showed significantly decreased pNKCs after the immunotherapy compared to before (MD, -8.20 95 %CI -10.20 - -6.19; p < 0, 00001). Additionally, there is an association between high pNKCs and the risk of pregnancy loss in women with RM. However, included studies showed substantial heterogeneities regarding the inclusion criteria of patients, techniques measuring pNKC, and types of immunotherapies. More studies are needed to evaluate the clinical efficiency of pNKCs in managing RM.

Correlation Between the Presence of Antinuclear Antibodies and Recurrent Pregnancy Loss: A Mini Review

In the past decade, the incidence of recurrent pregnancy loss (RPL) has increased significantly, and immunological disorders have been considered as one of the possible causes contributing to RPL. The presence of antinuclear antibodies (ANAs) is regarded as a typical antibody of autoimmunity. However, the relationship between the presence of ANAs and RPL, the underlying mechanism, and the possible role of immunotherapy is still controversial. The aim of this mini review is to assess the association between ANAs and RPL and the effects of immunotherapy on pregnancy outcomes in women with positive ANAs and a history of RPL from the available data and to provide a relevant reference basis for clinical application in this group of women.

The Impact of New Immunological Therapeutic Strategies on Recurrent Miscarriage and Recurrent Implantation Failure

Maternal-fetal immune dysregulation is one of the risk factors that increases the probability of embryo rejection and reproductive failure. The stimulation of immunological tolerance and suppression of immunological rejection are prerequisites for protecting embryos and preventing immunological attacks. Hence, it appears that immunomodulatory and immunosuppressive therapies can manage reproductive failures by controlling immune cells. The current medical literature has shown that immunotherapy approaches and cell therapy have promising results in improving pregnancy outcomes and live birth rates. These outcomes are obtained by regulating maternal immune responses, and exerting positive effects on human reproductive processes.

High Dose Intravenous IgG Therapy Modulates Multiple NK Cell and T Cell Functions in Patients With Immune Dysregulation

Intravenous immunoglobulin (IVIG) is an effective immunomodulatory treatment for immune dysregulation diseases. However, the mechanisms by which it reduces systemic inflammation are not well understood. NK cell cytotoxicity is decreased by IVIG in women with reduced fertility, but IVIG effects on NK cells in immune dysregulation are less clear. We hypothesized that IVIG modulation of lymphocyte function, especially in NK cells, is important for resolution of inflammation. Our aim was to identify IVIG-induced changes in a cohort of patients with Kawasaki disease (KD) and those that occur broadly in pediatric patients with various immune dysregulatory diseases. Peripheral blood mononuclear cells (PBMCs) of patients with KD or autoimmune/inflammatory diseases were phenotyped pre and post high dose IVIG treatment by flow cytometry. In KD patients, after IVIG infusion T_reg cell frequency and the proportion of activated CD25⁺ immunoregulatory CD56^bright NK cells was increased, and multiple lymphocyte subsets showed increased expression of the lymphoid tissue homing receptor CD62L. Importantly, IVIG treatment decreased the frequency of cells expressing the degranulation marker CD107a among cytotoxic CD56^dim NK cells, which was reflected in a significant reduction in target cell killing and in decreased production of multiple pro-inflammatory mediators. Interestingly, the activating receptor CD336 was expressed on a higher proportion of CD56^bright NK cells after IVIG in both KD and autoimmune/inflammatory patients while other NK receptors were increased differentially in each cohort. In autoimmune/inflammatory patients IVIG induced the proliferation marker CD71 on a higher percentage of CD56^dim NK cells, and in contrast to KD patients, CD107a⁺ cells were increased in this subset. Furthermore, when PBMCs were stimulated ex vivo with IL-2 or Candida antigen in autologous plasma, more of the CD4⁺ T cells of KD patients expressed CD25 after IVIG therapy but fewer cytotoxic T cells were degranulated based on CD107a expression. In summary, IVIG treatment in patients with immune dysregulation has multiple effects, especially on NK cell subsets and CD4⁺ T cells, which are compatible with promoting resolution of inflammation. These novel findings provide insight into the immunomodulatory actions of IVIG in autoimmune and inflammatory conditions.

Is there a Role of Intravenous Immunoglobulin in Immunologic Recurrent Pregnancy Loss?

Recurrent pregnancy loss (RPL) commonly refers to three or more miscarriages that occur before 20 weeks of pregnancy. The immunological cause of RPL could be either an auto- or alloimmune-related event or both. Because of the discovery of immunological abnormalities in RPL patients in clinical practice, several immunomodulatory therapies were introduced to maintain the immune balance at the maternal-fetal interface. Intravenous immunoglobulin (IVIg) is one of the immunomodulators. In recent years, several studies have analyzed the therapeutic effect of IVIg on RPL patients with antiphospholipid syndrome (APS) or unexplained RPL. However, their results are controversial. IVIg can be used in RPL patients with APS who have previously failed in other treatments. It is recommended that IVIg infusion could be considered used before conception in RPL patients who have cellular immune abnormalities such as increased natural killer (NK) cell counts, NK cell cytotoxicity, or increased T helper (Th)1/Th2 ratio, depending on the cut-off values of each hospital. The aim of this review was to summarize the mechanisms, efficacy, pharmacokinetics, and side effects associated with passive immunization using IVIg in immunologic RPL, according to the literature published in recent years. We hope that more obstetricians will be able to understand the timing and indication of IVIg properly in immunologic RPL patients and effectively enhance pregnancy outcomes for mothers and neonates.

Modulatory effect of intravenous immunoglobulin on Th17/Treg cell balance in women with unexplained recurrent spontaneous abortion

Recurrent spontaneous abortion (RSA) is a growing problem worldwide. In a majority of cases, the cause remains unknown but there is increasing evidence that immunologic factors play an important role. Intravenous immunoglobulin (IVIg) therapy has been proposed to have immune modulatory effects and therefore been applicable for the treatment of patients with RSA. Although its efficacy is still controversial, several recent studies suggest that IVIg treatment may improve pregnancy outcomes. CD4⁺ T cells and their related cytokines play an important role in maternal-fetal immune regulation, and an imbalance of Th17/Treg cell ratio has been proposed as a cause for RSA. We review the scientific evidence supporting a modulatory effect of IVIg on Th17/Treg cell balance and discuss the potential mechanisms how IVIg might enhance Treg cells function. We propose that correction of Th17/Treg cell dysregulation could be one of the mechanisms that can explain the positive therapeutic effects of IVIg therapy. Consequently, selecting patients with abnormal Th17/Treg cell ratios could increase the success of IVIg therapy.

Intravenous immunoglobulin G in women with reproductive failure: The Korean Society for Reproductive Immunology practice guidelines

The task force of the Korean Society for Reproductive Immunology recommends intravenous immunoglobulin G treatment in women with reproductive failure, including recurrent pregnancy loss and/or repeated implantation failure, who show cellular immune factors such as abnormal natural killer cell levels, natural killer cell cytotoxicity, and/or type 1 T helper immunity.

The effect of intravenous immunoglobulin passive immunotherapy on unexplained recurrent spontaneous abortion: a meta-analysis

The aim of this study was to investigate the effect of passive immunotherapy using intravenous immunoglobulin (IVIG) on unexplained recurrent spontaneous abortion (RSA). Live birth rates were analysed and binary data were calculated using risk ratio and 95% confidence interval. Meta-analysis of 11 studies showed that the difference in the live birth rate between the IVIG treatment and placebo groups was on the margin of significance (RR = 1.25, 95% CI 1.00 to 1.56, P = 0.05). Both cumulative and trial sequential meta-analyses indicated potential beneficial effect of IVIG but the evidence was inconclusive. Subgroup analysis showed that the live birth rate in primary (RR = 0.88, 95% CI 0.71 to 1.07) and secondary (RR = 1.26, 95% CI 0.99 to 1.61) RSA patients was not significantly different between the IVIG and placebo groups. Live birth rate was significantly different when IVIG was administered before conception (RR = 1.67, 95% CI 1.30 to 2.14, P < 0.0001) but not after implantation (RR = 1.10, 95% CI 0.93 to 1.29). Evidence is insufficient to support the beneficial effects of IVIG on an unexplained RSA. Further high quality studies are needed to elucidate the effectiveness of IVIG.

Effects of polyvalent immunoglobulins in patients with recurrent pregnancy loss and antibodies to the choriocarcinoma cell line JEG-3

OBJECTIVE

The benefit of polyvalent immunoglobulins (IVIG) for patients with recurrent pregnancy loss (RPL) is controversially discussed. Anti-trophoblast antibodies as an expression of immune pathology have been associated with RPL. We investigated whether the antibody activity against the choriocarcinoma cell line JEG-3 in RPL patients is influenced in vitro by IVIG.

STUDY DESIGN

Sera of 110 unexplained RPL patients with positive anti-JEG-3 antibodies were coincubated with IVIG in different concentrations (10mg/ml, 20mg/ml, 40mg/ml). Coincubation with human albumin in identical concentrations served as control. Anti-JEG-3 reactivity was measured by using flow cytometry in comparisons with two in-house standards antibody probes of low and high reactivity as described before. Anti-JEG-3 reactivity above the 95% confidence interval of controls was defined as positive.

RESULTS

Incubating RPL sera with 10mg/ml IVIG significantly decreased anti-JEG-3 activity (p<0.001). Increasing IVIG concentration to 40mg/ml resulted in a slightly additionally reduction (p=0.42). In contrast, coincubation with albumin in identically concentrations did not affect anti-JEG-3 activity (p>0.40).

CONCLUSION

Coincubation with IVIG in vitro leads to a significant suppression of anti-JEG-3 activity in the sera of RPL patients.

Medium-dose intravenous immunoglobulin therapy for women with six or more recurrent miscarriages

This study aimed to evaluate changes in natural killer (NK) cell activity and the percentage of monocytes in women with recurrent miscarriage who received medium-dose intravenous immunoglobulin (IVIg) therapy. Fourteen women with a history of six or more recurrent miscarriages of unexplained etiology received 60-g IVIg therapy (20 g daily, for three days) during early gestation. NK cell activity in the peripheral blood decreased to 12% one week after therapy compared with before therapy (median, 22%, P < 0.001) and the percentage of monocytes increased from 5.2% to 7.5% (P < 0.005). Four pregnancies ended in live births of healthy neonates, whereas the other ten pregnancies ended in miscarriages. Excluding one miscarriage with a chromosomal abnormality, the live birth rate was 30.8% (4/13). The rate of reduction of NK cell activity in the success group (-58.8%) tended to be greater than that in the failure group (-14.8%, P = 0.057).

Immunotherapy for recurrent miscarriage

BACKGROUND

Because immunological aberrations might be the cause of miscarriage in some women, several immunotherapies have been used to treat women with otherwise unexplained recurrent pregnancy loss.

OBJECTIVES

The objective of this review was to assess the effects of any immunotherapy, including paternal leukocyte immunization and intravenous immunoglobulin on the live birth rate in women with previous unexplained recurrent miscarriages.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (11 February 2014) and reference lists of retrieved studies.

SELECTION CRITERIA

Randomized trials of immunotherapies used to treat women with three or more prior miscarriages and no more than one live birth after, in whom all recognized non-immunologic causes of recurrent miscarriage had been ruled out and no simultaneous treatment was given.

DATA COLLECTION AND ANALYSIS

The review author and the two co-authors independently extracted data and assessed study quality for all studies considered for this review.

MAIN RESULTS

Twenty trials of high quality were included. The various forms of immunotherapy did not show significant differences between treatment and control groups in terms of subsequent live births: paternal cell immunization (12 trials, 641 women), Peto odds ratio (Peto OR) 1.23, 95% confidence interval (CI) 0.89 to 1.70; third-party donor cell immunization (three trials, 156 women), Peto OR 1.39, 95% CI 0.68 to 2.82; trophoblast membrane infusion (one trial, 37 women), Peto OR 0.40, 95% CI 0.11 to 1.45; or intravenous immunoglobulin, (eight trials, 303 women), Peto OR 0.98, 95% CI 0.61 to 1.58.

AUTHORS' CONCLUSIONS

Paternal cell immunization, third-party donor leukocytes, trophoblast membranes, and intravenous immunoglobulin provide no significant beneficial effect over placebo in improving the live birth rate.

A high dose intravenous immunoglobulin therapy for women with four or more recurrent spontaneous abortions

Recurrent spontaneous abortion (RSA) may have immunological etiology. The aim of this study was to assess the efficacy of a high dose intravenous immunoglobulin (HIVIg) therapy, in which 20 g of intact type immunoglobulin was infused daily for 5 days during early gestation, for women who had a history of four or more consecutive spontaneous abortions of unexplained etiology. A total of 60 pregnant RSA women underwent HIVIg therapy, and the pregnancy outcome was assessed. The live birth rate was 73.3% (44/60). Fifteen pregnancies ended in spontaneous abortion, and one ended in intrauterine fetal death. In 11 of the 15 spontaneous abortions, fetuses had abnormal chromosome karyotype. When the 11 pregnancies with abnormal chromosome karyotype were excluded, the live birth rate was as high as 89.8% (44/49). The HIVIg therapy may be effective for severe cases of unexplained RSA.

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

PROBLEM

To analyse the peripheral blood NK cells in women with repeated IVF failure (RIF) and a fertile control group to determine which parameters best differentiate the two populations.

METHODS

Peripheral blood from the luteal phase of 171 women with RIF and 33 fertile controls was analysed by four-colour flow cytometry for NK cell concentration, subset differentiation and the activation marker CD69.

RESULTS

Women with RIF had significantly increased NK cell numbers as determined by concentration (P < 0.05) and percentage of lymphocytes (P < 0.001), increased concentration of the CD56(dim) subtype (P < 0.05), and increased concentration of activated CD56(dim) CD69(+) cells (P = 0.0001). There was no correlation between any NK cell parameters with the length of infertility or number of embryo transfer cycles.

CONCLUSIONS

Peripheral blood NK cell activity is significantly higher in women with RIF than in fertile controls. Future trials of immune therapy in women undergoing IVF should target those with high NK activity.

Intravenous immunoglobulin therapy for aspirin-heparinoid-resistant antiphospholipid syndrome

We encountered a woman who had a history of repeated fetal losses and positive tests for lupus anticoagulant, phosphatidylserine-dependent antiprothrombin (aPS/PT) IgG, IgM and kininogen-dependent antiphosphatidylethanolamine (aPE) IgG, IgM. Her previous pregnancy had ended in intrauterine fetal death at 24 weeks of gestation despite a therapy of low-dose aspirin, prednisolone and danaparoid. During the present pregnancy, she was treated with repeated intravenous infusions of immunoglobulin (IVIg) together with low-dose aspirin, prednisolone and heparin. When thrombocytopenia developed, she delivered a female baby weighing 2,152 g at 34 weeks of gestation by cesarean section. Titers of aPS/PT IgM and aPE IgM were reduced or maintained at low levels by repeated IVIg therapies. The IVIg therapy might be effective for aspirin-heparinoid-resistant antiphospholipid syndrome.

A high dose of intravenous immunoglobulin increases CD94 expression on natural killer cells in women with recurrent spontaneous abortion

PROBLEM

A high dose of intravenous immunoglobulin (HIVIg) therapy is effective in various diseases such as autoimmune diseases, and also is expected to have efficacy in recurrent spontaneous abortion (RSA). The aim of this study was to understand immunological mechanisms of this therapy.

METHOD OF STUDY

By flowcytometric analyses, we examined phenotypic changes of a variety of immunological cells including natural killer (NK) cells, cytotoxic T cells, regulatory T cells and macrophages in peripheral blood of RSA women with HIVIg therapy (n = 8).

RESULTS

Expression percentages of inhibitory CD94 on NK cells significantly (P = 0.01) increased after the therapy (58.8 +/- 21.4% versus 71.0 +/- 17.6%).

CONCLUSION

Mechanisms of possible efficacy of HIVIg therapy for RSA may include enhancement of CD94 expression and subsequent suppression of NK cell cytotoxicity.

Anti-phospholipid antibodies and other immunological causes of recurrent foetal loss--a review of literature of various therapeutic protocols

PROBLEM

An immune-based aetiology is one of the several accepted causes for recurrent foetal loss (RFL). However, most of the immunological theories have not fulfilled the criteria for causality. This is a review of the various immunological causes of RFL and the outcome of different treatment protocols.

METHOD OF STUDY

Both auto- and alloimmune maternal immunological abnormalities have been proposed to account for foetal loss. Among the autoimmune factors, anti-phospholipid antibodies (APAs) have been demonstrated to be the strongest risk factors for foetal loss, the prevalence of which is as high as 40% in women with RFL. Other autoimmune antibodies implicated in RFL are anti-nuclear antibodies (ANAs), anti-thyroid antibodies and anti-endothelial cell antibodies. The alloimmune factors implicated in pregnancy loss of unknown aetiology include abnormal natural killer (NK) cell activity, alteration in T helper 1 (Th1) and T helper 2 (Th2) ratios, presence of alloimmune antibodies like anti-paternal cytotoxic antibodies, anti-idiotypic antibodies, mixed lymphocyte reaction blocking antibodies and abnormal expression of HLA-G molecules. Management of patients with RFL is mainly based on immunomodulatory (prednisolone, intravenous immunoglobulins, plasma exchange, paternal lymphocyte therapy), anti-aggregation (aspirin) or anti-coagulation (unfractionated or low molecular weight heparin) agents.

RESULTS

Low-molecular-weight heparin with low-dose aspirin has been found to be the most effective treatment for women with APAs and RFL. Differences in dosage, timing of treatment, inclusion criteria, outcome assessment parameters etc. are some of the factors which have resulted in discrepancies in various reports.

CONCLUSION

Identification of the immunological mechanisms involved in pregnancy loss and the action of different therapeutic reagents is important so that effective therapies can be designed and investigated.

Administration of high-dose intact immunoglobulin has an anti-resorption effect in a mouse model of reproductive failure

Administration of high-dose intact human immunoglobulin (IH-Ig) has been applied to treat a variety of inflammatory and autoimmune diseases, and is expected to have beneficial effects on human fecundity. In the present study, we investigated whether Ig had anti-resorption effects using polyinosinic-polycytidylic acid sodium salt [poly (I:C)]-induced enhancement of fetal resorption in the mating of CBA/J x DBA/2J resorption-prone mouse model. Furthermore, we investigated the mechanism of the effect by examining the mRNA expression of interferon (IFN)-gamma, tumor necrosis factor (TNF)-alpha, IL-10, IL-4 and TGF-beta(1) in spleens and placentas from the resorption-prone model treated with IH-Ig, by reverse transcription (RT)-polymerase chain reaction (PCR). Administration of high-dose IH-Ig significantly reduced the fetal resorption rate from 55% to 10%. This anti-resorption effect, however, was not detected in mice administered with Fab fragments of human Ig. We then performed adoptive transfer experiments to examine whether cellular components could transfer the effect. A remarkable anti-resorption effect was seen in poly (I:C)-injected pregnant recipients transferred with spleen cells from IH-Ig-treated donor mice. The RT-PCR study showed that IH-Ig reduced the expression of IFN-gamma and TNF-alpha mRNA in placentas of poly (I:C)-injected pregnant mice. The present findings demonstrate that intact Ig, particularly its Fc portion, possesses anti-resorption activity. The effect might be attributed to the suppressed production of pro-inflammatory cytokines at the maternofetal interface.

Immunotherapy for recurrent miscarriage

BACKGROUND

Because immunological aberrations might be the cause of miscarriage in some women, several immunotherapies have been used to treat women with otherwise unexplained recurrent pregnancy loss.

OBJECTIVES

The objective of this review was to assess the effects of any immunotherapy, including paternal leukocyte immunization and intravenous immune globulin on the live birth rate in women with previous unexplained recurrent miscarriages.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group Trials Register (December 2005), the Cochrane Central Register of Controlled Trials (The Cochrane Library 2004, Issue 3), MEDLINE (1966 to September 2004) and EMBASE (1980 to September 2004).

SELECTION CRITERIA

Randomized trials of immunotherapies used to treat women with three or more prior miscarriages and no more than one live birth after, in whom all recognised non-immunologic causes of recurrent miscarriage had been ruled out and no simultaneous treatment was given.

DATA COLLECTION AND ANALYSIS

The review author and the two co-authors independently extracted data and assessed study quality for all studies considered for this review.

MAIN RESULTS

Twenty trials of high quality were included. The various forms of immunotherapy did not show significant differences between treatment and control groups in terms of subsequent live births: paternal cell immunization (12 trials, 641 women), Peto odds ratio (Peto OR) 1.23, 95% confidence interval (CI) 0.89 to 1.70; third party donor cell immunization (three trials, 156 women), Peto OR 1.39, 95% CI 0.68 to 2.82; trophoblast membrane infusion (one trial, 37 women), Peto OR 0.40, 95% CI 0.11 to 1.45; intravenous immune globulin, Peto OR 0.98, 95% CI 0.61 to 1.58.

AUTHORS' CONCLUSIONS

Paternal cell immunization, third party donor leukocytes, trophoblast membranes, and intravenous immune globulin provide no significant beneficial effect over placebo in improving the live birth rate.

An update in recurrent spontaneous abortion

Recurrent spontaneous abortion (RSA) is defined as three or more consecutive pregnancy losses prior to the 20th week of gestation. The etiology of recurrent spontaneous abortion is often unclear and may be multifactorial, with much controversy regarding diagnosis and treatment. Reasonably accepted etiologic causes include, genetics, anatomical, endocrine, placental anomalies, hormonal problems, infection, smoking and alcohol consumption, exposure to environmental factors, psychological trauma and stressful life event, certain coagulation and immunoregulatory protein defects. Detection of an abnormality in any of these areas may result into specific therapeutic measures, with varying degrees of success. However, the majority of cases of RSA remains unexplained and is found to be associated with certain autoimmune (APA, ANA, ACA, ATA, AECA) and alloimmune (APCA, Ab2, MLR-Bf) antibodies that may play major role in the immunologic failure of pregnancy and may lead to abortion. Alteration in the expression of HLA-G molecules, T-helper-1 (Th-1) pattern of cytokines and natural killer (NK) cells activity may also induce abortion. Various forms of treatment like antithrombotic therapies such as aspirin and heparin, intravenous immunoglobulin (IVIg) therapy, immunotherapy with paternal lymphocytes and vitamin D3 therapy are effective mode of treatment for unexplained cause of fetal loss in women with RSA.

Preconception Peripheral Natural Killer Cell Activity as a Predictor of Pregnancy Outcome in Patients with Unexplained Infertility

PROBLEM

Preconception high peripheral natural killer (NK) cell activity in women with recurrent spontaneous abortion can predict subsequent miscarriages. We have examined prospectively, for the first time, the pregnancy rate in patients with unexplained infertility by measuring the peripheral NK activity.

METHOD OF STUDY

We tested the peripheral NK activity of 94 infertile women who despite treatment were unable to conceive for 6 or more months (mean; 2.4 years). Peripheral NK activity was measured by a chromium-51 release cytotoxicity assay. Women were followed for 2 years and assessed.

RESULTS

In 77 patients who were followed for 2 years, 28 had conceived but 49 did not. The peripheral NK activity of the group that became pregnant (mean +/- S.D.; 34.5 +/- 13.8%) was significantly lower than that of non-conception group (42.3 +/- 13.3%, P = 0.017).

CONCLUSIONS

Our finding suggests that elevated peripheral NK activity in patients with unexplained infertility is a risk factor for attaining pregnancy success.

Embryo loss pattern is predominant in miscarriages with normal chromosome karyotype among women with repeated miscarriage

OBJECTIVE

The aim of this study was to assess pregnancy loss patterns in women with repeated miscarriage (RM), according to fetal chromosome karyotypes and aetiologies of RM.

METHODS

In this cohort study, 168 fetal chromosome karyotypes of miscarriages were investigated. The pregnancy loss patterns were compared between 75 miscarriages from RM women who had a history of two or more consecutive miscarriages and 93 miscarriages from control women whose previous pregnancies ended in live births without a history of RM. By serial ultrasonography, embryo loss (EL) was defined as miscarriage before fetal heat movement was identified and fetal loss (FL) as miscarriage after fetal heat movement was identified. The EL rate was calculated as EL/(EL+FL).

RESULTS

The EL rate (66.7%) in miscarriages with normal karyotypes among RM women (n=42) was higher (P<0.05) than that (45.7%) in controls (n=46), while the EL rate (30.3%) in miscarriages with abnormal karyotypes among RM women (n=33) did not differ from that (25.5%) in the controls (n=47). The EL rate (71.4%) in miscarriages with normal karyotypes among unexplained RM women (n=21) was much higher (P<0.05) than that in the controls.

CONCLUSIONS

By evaluating fetal karyotypes, we demonstrated for the first time that EL was predominant in miscarriages with normal karyotype among RM women.

Effect of IgG therapy on lymphocyte subpopulations in the peripheral blood of Kuwaiti women experiencing recurrent pregnancy loss

Intravenously administered polyspecific IgG is being increasingly used as an immunomodulating therapy with controversial beneficial outcome. The aim of this study was to evaluate the effects of IgG infusion on peripheral T-cell subpopulations in women with recurrent pregnancy loss (RPL). Fifteen women with a history of three previous RPL between 6 and 22 weeks of gestation and positivity for the antiphospholipid antibody syndrome (APS) were randomized to one of two treatment groups: (a) an intravenous immunoglobulin therapy group (RPL-IVIg; 7 patients), 500 mg IVIg/kg/month and (b) a placebo-treated group given multivitamins (8 patients). Control groups comprised either normal pregnant women without APS (10 patients) or non-pregnant women. The T-cell markers were characterized using a monoclonal antibody panel including CD3, CD4, CD8, CD25, CD29, CD38, CD45RA, CD45RO, CD54 and HLA-DR. Analysis was performed with a two-color fluorescent-activated flow cytometer. In the first trimester, the percentage of CD4+CD25+, CD4+CD45RO+, CD8+HLA-DR+, and CD8+CD38+ populations were reduced in the multivitamin group compared to normal pregnant women (p < 0.05) while in the RPL-IVIg group only CD4+CD25+ cells were reduced (p < 0.05). By the second trimester, CD3+CD16+CD56+ was significantly higher in multivitamin- than in IVIg-treated women (p < 0.05). The percentage of CD4+HLA-DR+ was significantly higher in the two RPL groups compared to normal pregnant women (p < 0.05). IVIg therapy in women with RPL was associated with a significant reduction in CD3+CD16+CD56+ and CD4+CD25+. This may contribute to the suppression of immune-mediated processes contributing to premature abortion.

The Effect of Valacyclovir Treatment on Natural Killer Cells of Infertile Women

PROBLEM

The aim of this study was to investigate the effect of valacyclovir treatment on natural killer (NK) cell concentration in the peripheral blood of infertile women.

METHOD OF STUDY

Peripheral blood NK cell concentration of 104 non-pregnant women with a history of infertility was determined by flow cytometry. The controls were 14 fertile non-pregnant women. A cohort of 42 out of 104 women--whose NK cell levels were 175/microL or higher--was prospectively studied for the presence of HSV-1, 2, VZV, cytomegalovirus, HHV-6, HHV-7 and HHV-8 DNA in the peripheral blood and was orally administered valacyclovir (open label study).

RESULTS

Herpes virus DNA was detected in 64.3% of the 42 women examined. Prior to valacyclovir treatment mean NK cell concentration in herpes-negative group was statistically higher from control group but lower from herpes positive group (P = 0.0007, ANOVA). Following valacyclovir treatment the mean NK cell concentration was statistically decreased in all studied women (P = 0.000453), in herpes-negative (P = 0.01622) and in herpes positive group (P = 0.0056). Sufficient decrease was observed in 31 (73.8%) of 42 women who received the drug.

CONCLUSIONS

Valacyclovir treatment is associated with a decrease of NK cell levels in most of the women with a history of infertility.

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.

Intravenous immunoglobulin treatment in women with recurrent abortions: increased cytokine levels and reduced Th1/Th2 lymphocyte ratio in peripheral blood

PROBLEM

The aim of this study was to investigate changes in peripheral blood Th1/Th2 cytokine levels and lymphocyte ratios after massive intravenous immunoglobulin (MIVIg) treatment for women with recurrent spontaneous abortion (RSA) of unexplained etiology.

METHOD OF STUDY

Serum Th1 (IFN-gamma, TNF-alpha) and Th2 cytokine (IL-4, IL-10) levels were assessed by ELISA methods (n = 9) and peripheral blood Th1/Th2 lymphocyte ratios (n = 4) by flow cytometry before and after MIVIg treatments in women with four or more consecutive RSA.

RESULTS

Pre-treatment serum IFN-gamma (0.06 +/- 0.09 pg/mL, mean +/- SD), TNF-alpha (0.21 +/- 0.45 pg/mL), IL-4 (0.70 +/- 1.16 pg/mL), and IL-10 (1.12 +/- 1.67 pg/mL) increased to 0.17 +/- 0.16 pg/mL, 0.77 +/- 0.28 pg/mL, 1.82 +/- 0.89 pg/mL, and 3.44 +/- 0.48 pg/mL, respectively, after MIVIg treatments (P < 0.05). CD4-positive IFN-gamma/IL-4 lymphocyte ratios (17.3 +/- 9.1) were reduced to 11.5 +/- 7.1 after treatment (P < 0.05).

CONCLUSIONS

Massive intravenous immunoglobulin treatments increased peripheral blood cytokine levels and decreased Th1/Th2 lymphocyte ratios; thus, MIVIg treatments modify the peripheral Th1/Th2 balance.

Effect of intravenous immunoglobulin treatment on the Th1/Th2 balance in women with recurrent spontaneous abortions

PROBLEM

The way by which intravenous immunoglobulin (IvIg) acts to prevent immunlogically mediated recurrent spontaneous abortions (RSA) has not been clarified. In the present study, a possible effect of IvIg on the T helper cell (Th1/Th2) balance was investigated in abortions of either alloimmune or autoimmune abnormalities.

METHOD OF STUDY

The study included 21 women treated with IvIg before conception because of a history of RSA characterized by alloimmune abnormalities (n = 15) or associated with anti-phospholipid antibodies (APA) (n = 6). Peripheral blood samples, collected before and 5 days after the first IvIg infusion, were stimulated, and Th1 and Th2 cells were detected by flow-cytometric analysis using a combination of monoclonal antibodies against T-cell surface markers and intracellular interferon (IFN)-gamma and interleukin (IL)-4. The percentage of IFN-gamma-producing (Th1) and IL-4-producing (Th2) cells and the Th1/Th2 ratio were compared between pre- and post-infusion samples.

RESULTS

A decrease of Th1 percentage in 66.6% of the cases and a concurrent Th2 percentage increase (47.61%) resulted in a decrease in the Th1/Th2 ratio in most of the cases (76.1%) (p < 0.01). Similar results were found in Group A (Th1/Th2 decreased in 60% of the cases, p < 0.05), while in Group B the effect of IvIg was not clear (Th1/Th2 increased in three and decreased in another three cases).

CONCLUSION

Our finding suggests that IvIg administration in women with alloimmune RSA enhances Th2 polarization. This is not always the case with APA-associated abortions.