Intravenous immunoglobulin therapy for recurrent spontaneous abortion: a meta-analysis

The Role of Uterine Natural Killer Cells on Recurrent Miscarriage and Recurrent Implantation Failure: From Pathophysiology to Treatment

Uterine natural killer (uNK) cells constitute a unique uterine leucocyte subpopulation facilitating implantation and maintaining pregnancy. Herein, we critically analyze current evidence regarding the role of uNK cells in the events entailed in recurrent implantation failure (RIF) and recurrent miscarriages (RM). Data suggest an association between RIF and RM with abnormally elevated uNK cells’ numbers, as well as with a defective biological activity leading to cytotoxicity. However, other studies do not concur on these associations. Robust data suggesting a definitive causative relationship between uNK cells and RIF and RM is missing. Considering the possibility of uNK cells involvement on RIF and RM pathophysiology, possible treatments including glucocorticoids, intralipids, and intravenous immunoglobulin administration have been proposed towards addressing uNK related RIF and RM. When considering clinical routine practice, this study indicated that solid evidence is required to report on efficiency and safety of these treatments as there are recommendations that clearly advise against their employment. In conclusion, defining a causative relationship between uNK and RIF–RM pathologies certainly merits investigation. Future studies should serve as a prerequisite prior to proposing the use of uNK as a biomarker or prior to targeting uNK cells for therapeutic purposes addressing RIF and RM.

Uterine natural killer cells: from foe to friend in reproduction

BACKGROUND

Recurrent miscarriage and pre-eclampsia are common reproductive disorders, but their causes are often unknown. Recent evidence has provided new insight into immune system influences in reproductive disorders. A subset of lymphocytes of the innate immune system known as uterine natural killer (uNK) cells are now recognized as fundamental to achieving embryo implantation and successful pregnancy, but were initially attributed a bad reputation. Indeed, immune therapies have been developed to treat the 'exaggerated' immune response from uNK cells. These treatments have been based on studies of peripheral blood natural killer (pbNK) cells. However, uNK cells and pbNK cells have different phenotypic and functional characteristics. The functions of uNK cells are closely related to their interactions with the extravillous trophoblast cells (EVTs) and spiral arteries, which underlie an essential role in regulating vascular function, controlling trophoblast invasion and promoting placental development. EVTs express MHC molecules of class I HLA-C/E/G/F, while uNK cells express, among other receptors, killer cell immunoglobulin-like receptors (KIRs) that bind to HLA-C or CD94/NKG2A inhibitory receptors, and then bind HLA-E. Associations of certain KIR/HLA-C combinations with recurrent miscarriage, pre-eclampsia, and foetal growth restriction and the interactions between uNK cells, trophoblasts and vascular cells have led to the hypothesis that uNK cells may play a role in embryo implantation.

OBJECTIVE AND RATIONALE

Our objective was to review the evolution of our understanding of uNK cells, their functions, and their increasingly relevant role in reproduction.

SEARCH METHODS

Relevant literature through June 2020 was retrieved using Google Scholar and PubMed. Search terms comprised uNK cells, human pregnancy, reproductive failure, maternal KIR and HLA-C, HLA-E/G/F in EVT cells, angiogenic cytokines, CD56+ NK cells, spiral artery, oestrogen and progesterone receptors, KIR haplotype and paternal HLA-C2.

OUTCOMES

This review provides key insights into the evolving conceptualization of uNK cells, from their not-so-promising beginnings to now, when they are considered allies in reproduction. We synthesized current knowledge about uNK cells, their involvement in reproduction and their main functions in placental vascular remodeling and trophoblast invasion. One of the issues that this review presents is the enormous complexity involved in studying the immune system in reproduction. The complexity in the immunology of the maternal-foetal interface lies in the great variety of participating molecules, the processes and interactions that occur at different levels (molecular, cellular, tissue, etc.) and the great diversity of genetic combinations that are translated into different types of responses.

WIDER IMPLICATIONS

Insights into uNK cells could offer an important breakthrough for ART outcomes, since each patient could be assessed based on the combination of HLA and its receptors in their uNK cells, evaluating the critical interactions at the materno-foetal interface. However, owing to the technical challenges in studying uNK cells in vivo, there is still much knowledge to gain, particularly regarding their exact origin and functions. New studies using novel molecular and genetic approaches can facilitate the identification of mechanisms by which uNK cells interact with other cells at the materno-foetal interface, perhaps translating this knowledge into clinical applicability.

A systemic review of intravenous immunoglobulin G treatment in women with recurrent implantation failures and recurrent pregnancy losses

Over the last few decades, the advancement in reproductive technologies and protocols to improve embryo quality through culture techniques and genetic testing to eliminate chromosomally abnormal embryos resulted in better pregnancy rates and outcomes after fertility treatments. Unfortunately, some patients still struggle with recurrent implantation failures (RIFs) and recurrent pregnancy losses (RPLs). Immune etiologies have been attributed to play an important role in some of those patients. Maintaining a pre-conceptional anti-inflammatory environment for implantation and pregnancy continuation yields superior results. Intravenous immunoglobulin G (IVIG) treatment has been reported to enhance reproductive outcome in patients with RIF and RPL with immune dysregulations. In this systemic review, we analyzed outcomes of IVIG trials for RIF and RPL, its mechanism of action, dosing, administration, side-effects, and evidence for its use in women with RIF and RPL.

NK cell frequency and cytotoxicity in correlation to pregnancy outcome and response to IVIG therapy among women with recurrent pregnancy loss

BACKGROUND

Recurrent miscarriage (RM) has a multifactorial etiology mainly due to chromosomal abnormalities and immunological factors. Treating RM has remained to be a challenging issue and the role of intravenous immunoglobulin (IVIG) in treating RM is still controversial.

MATERIALS AND METHODS

This study aimed to evaluate the changes in natural killer (NK) cells' frequency and cytotoxicity in patients with RM who received the IVIG therapy. A total of 78 women with a history of three or more recurrent miscarriages were included and their peripheral blood was drawn in case of positive pregnancy test. On the same date, 400 mg/kg of IVIG was administrated intravenously in 38 women and it continued every four weeks through weeks 30-32 of gestation. The remaining 40 patients with RM were included to be the untreated control group. Then, the effects of IVIG on NK cell frequency, cytotoxic activity, and the expression of inhibitory and activating receptors in the patients with RM, pre and posttreatment were assessed.

RESULTS

NK cells percentage and cytotoxicity were significantly reduced in the IVIG-treated patients after 32 weeks of gestation (p < 0.0001). Expression levels of inhibitory receptors was increased, however, the expression levels of activating receptors were significantly decreased after the IVIG therapy. Pregnancy outcome after the treatment was significantly higher (86.8%) in the IVIG-treated patients than controls (45%; p = 0.0006).

CONCLUSION

Our results suggested that women with RM may benefit from IVIG as a therapeutic approach and the frequency and functional status of peripheral NK cells may serve as a valuable predictive factor of therapy response.

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.

Polyclonal and monoclonal antibodies in clinic

Immunoglobulins (Ig) or antibodies are heavy plasma proteins, with sugar chains added to amino-acid residues by N-linked glycosylation and occasionally by O-linked glycosylation. The versatility of antibodies is demonstrated by the various functions that they mediate such as neutralization, agglutination, fixation with activation of complement and activation of effector cells. Naturally occurring antibodies protect the organism against harmful pathogens, viruses and infections. In addition, almost any organic chemical induces antibody production of antibodies that would bind specifically to the chemical. These antibodies are often produced from multiple B cell clones and referred to as polyclonal antibodies. In recent years, scientists have exploited the highly evolved machinery of the immune system to produce structurally and functionally complex molecules such as antibodies from a single B clone, heralding the era of monoclonal antibodies. Most of the antibodies currently in the clinic, target components of the immune system, are not curative and seek to alleviate symptoms rather than cure disease. Our group used a novel strategy to identify reparative human monoclonal antibodies distinct from conventional antibodies. In this chapter, we discuss the therapeutic relevance of both polyclonal and monoclonal antibodies in clinic.

Safety of intravenous immunoglobulin treatment

IMPORTANCE OF THE FIELD

Intravenous immunoglobulin (IVIg) is a biologic pharmaceutical that is widely used to treat immunodeficiency conditions and a variety of autoimmune conditions. It is under-recognized that IVIg can be associated with severe complications including death.

AREAS COVERED IN THIS REVIEW

This review will address common mild side effects and extensively discuss the uncommon but serious complications of IVIg. Mild constitutional reactions include headache, fever and rash and severe complications include anaphylaxis, acute renal failure, stroke and myocardial infarction. IVIg has been used to treat autoimmune illnesses for ~30 years and the literature since then is reviewed with special attention to reports in the last 10 years that detail the serious adverse events.

WHAT THE READER WILL GAIN

The reader will understand that mild side effects are common and that these can be ameliorated with pre-treatment medications. They will also become familiar with the risk factors for serious complications so that careful patient and IVIg product selection will result in fewer poor outcomes.

TAKE HOME MESSAGE

IVIg is quite safe across age groups although serious adverse reactions occur particularly in elderly individuals with multiple cardiovascular risk factors and those with preexisting renal failure.

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.

Unlabeled uses of intravenous immune globulin

PURPOSE

The unlabeled uses of intravenous immune globulin (IVIG) were reviewed.

SUMMARY

A literature review was conducted to identify studies examining the unlabeled uses of IVIG. A review of 138 clinical trial abstracts identified 10 trials examining 2 labeled uses (635 patients) and 128 trials examining 61 different off-label uses (6781 patients). The most common off-label indications included multiple sclerosis, graft-versus-host disease in transplant patients, prevention of antiphospholipid syndrome in miscarriage, Guillain-Barré syndrome, and progression of human immunodeficiency virus after delivery. The studies appeared to support many of the acceptable off-label uses cited by various guideline groups. A total of 276 case reports were identified, with 268 reports representing 156 different off-label uses (362 patients). Seven meta-analyses were identified, evaluating recurrent miscarriage, in vitro fertilization failure, infection in preterm infants, multiple sclerosis, immune thrombocytopenic purpura, and pemphigoid. With the exception of recurrent miscarriage and infection in preterm infants, the off-label use of IVIG for these indications was associated with positive outcomes. An examination of IVIG guidelines by specialty society, payer, and other review organizations revealed that the biomedical evidence supporting off-label uses is being interpreted in different ways. Health care institutions are strongly urged to approve and closely monitor specific uses of IVIG to reserve dwindling supplies for the "best-evidence" uses. Clinicians should be aware of the limits of knowledge in many off-label uses and exercise restraint in prescribing for unproven indications.

CONCLUSION

A literature review identified more than 150 unlabeled uses of IVIG. The evidence for these uses is being interpreted in different ways by various reviewing organizations.

Modulation of the cellular immune system by intravenous immunoglobulin

Intravenous immunoglobulin (IVIg) is therapeutically used in a variety of immune-mediated diseases. The beneficial effects of IVIg in auto-antibody-mediated diseases can be explained by neutralization, accelerated clearance and prevention of Fcgamma-receptor binding of auto-antibodies. However, the means by which IVIg exerts therapeutic effects in disorders mediated by cellular immunity have remained enigmatic. Clinical improvements, followed by IVIg treatment, often extend beyond the half-life of infused IgG, thereby indicating that IVIg modifies the cellular immune compartment for a prolonged period. Here, we discuss recent advances in the understanding of different, mutually non-exclusive mechanisms of action of IVIg on cells of the innate and adaptive immune system. These mechanisms might explain the beneficial effects of IVIg in certain autoimmune and inflammatory diseases.

Use of intravenous immunoglobulin for treatment of recurrent miscarriage: a systematic review

BACKGROUND

Intravenous immunoglobulin (IVIG) is a fractionated blood product whose off-label use for treating a variety of conditions, including spontaneous recurrent miscarriage, has continued to grow in recent years. Its high costs and short supply necessitate improved guidance on its appropriate applications.

OBJECTIVE

We conducted a systematic review of randomised controlled trials evaluating IVIG for treatment of spontaneous recurrent miscarriage.

SEARCH STRATEGY

A systematic search strategy was applied to Medline (1966 to June 2005) and the Cochrane Register of Controlled Trials (June 2005).

SELECTION CRITERIA

We included all randomised controlled trials comparing all dosages of IVIG to placebo or an active control.

DATA COLLECTION AND ANALYSIS

Two investigators independently extracted data using a standardised data collection form. Measures of effect were derived for each trial independently, and studies were pooled based on clinical and methodologic appropriateness.

MAIN RESULTS

We identified eight trials involving 442 women that evaluated IVIG therapy used to treat recurrent miscarriage. Overall, IVIG did not significantly increase the odds ratio (OR) of live birth when compared with placebo for treatment of recurrent miscarriage (OR 1.28, 95% CI 0.78-2.10). There was, however, a significant increase in live births following IVIG use in women with secondary recurrent miscarriage (OR 2.71, 95% CI 1.09-6.73), while those with primary miscarriage did not experience the same benefit (OR 0.66, 95% CI 0.35-1.26).

AUTHOR'S CONCLUSIONS

IVIG increased the rates of live birth in secondary recurrent miscarriage, but there was insufficient evidence for its use in primary recurrent miscarriage.

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.

Is intravenous immunoglobulins (IVIG) efficacious in early pregnancy failure? A critical review and meta-analysis for patients who fail in vitro fertilization and embryo transfer (IVF)

PROBLEM

Intravenous Immunoglobulins (IVIG) are widely used off label in the treatment of early reproductive failure. As IVIG is expensive, and may have side-effects, evidence of efficacy is needed. Previous results have suggested that the pre-conception treatment of primary recurrent abortion patients might be effective, but the data set has been too small for adequate statistical power. More recently it has been suggested that IVIG may improve the success rate of in vitro fertilization and embryo transfer (IVF) in patients with prior IVF failures, but clinical trials have given conflicting results that need explanation. Systematic reviews generating inconclusive results have focused on methodological rigor to the exclusion of biological plausibility.

METHODS

Review of current basic science of design, measurement, and evaluation of clinical trials and basic science mechanisms providing a rationale for treatment. Meta-analysis of published randomized controlled and cohort-controlled trials (updated with two unpublished data sets) evaluating IVIG treatment in IVF failure patients. Live birth rate was used as the most relevant endpoint. The ability of different sources of IVIG to suppress natural killer (NK) cell activity was determined using a standard (51)Cr-release assay in vitro.

RESULTS AND CONCLUSIONS

Meta-analysis of three published randomized controlled trials (RCTs) of IVIG in IVF failure patients shows a significant increase in the live birth rate per woman (p = 0.012; Number Needed to Treat for 1 additional live birth, NNT = 6.0 women). Using live birth rate per embryo transferred, and adding data from two cohort-controlled trials to the meta-analysis further supports this conclusion (overall p = 0.000015, NNT = 3.7 women). Relevant variables appear to include properties and scheduling of the IVIG, and selection of patients with abnormal immune test results. Different IVIG preparations vary significantly in their ability to suppress NK activity in vitro. A rationale for use of IVIG is provided by a review of mechanisms of IVIG action and mechanisms underlying failure of chromosomally normal embryos.

Update on Treatment of Immunologic Abortion with Low-dose Intravenous Immunoglobulin

PROBLEM

Recurrent spontaneous abortion associated with immunologic abnormalities has been termed immunologic abortion. Previously we showed that treatment with low-dose intravenous immunoglobulin (IVIG) appears to be beneficial for older women with immunologic abortion. We now report the results of IVIG treatment in a larger group of women with this disorder.

METHOD OF STUDY

A total of 99 women were prospectively evaluated for immunologic abortion, which was defined as three or more miscarriages and the presence of specific immunologic abnormalities. Prior to the next conception, patients were treated with IVIG at a dose of 0.2 g/kg. Once conception was achieved, IVIG treatment was continued on a monthly basis through 26-30 weeks of pregnancy.

RESULTS

The average age of the women was 37 years (range: 28-49), and the average number of miscarriages was 3.8 (range: 3-12). Of the 99 women, 72 received initial IVIG treatment, and 50 subsequently became pregnant. Of these women, 42 (84%) had a successful term pregnancy. Of the 27 women who refused IVIG therapy, 20 became pregnant and 18 (90%) miscarried. The difference in pregnancy success rate between the IVIG-treated and untreated groups was significant (P = 0.001). Four women had mild allergic reactions during IVIG infusion, and these reactions resolved when the IVIG brand was changed. Fetal abnormalities were not observed.

CONCLUSION

We conclude that low-dose IVIG therapy is safe and effective for older women with immunologic abortion.

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.

Natural killer cells, miscarriage, and infertility

Enthusiasm for new treatments aimed at natural killer cells in women with reproductive failure is unfortunately not backed up by the science

Is there a place for immunomodulation in assisted reproduction techniques?

We briefly review the history of the concepts of the materno foetal relationship, and the (various) rationales which have been used to justify lymphocyte alloimmunisation (LA) as a treatment for recurrent spontaneous abortion of putative immune origins. The effectiveness of the treatment is at best dubious and limited to a small number of women for which there is no real positive selection rationale, at worst it is not efficient. The rationales themselves are rather "evolutive". The present one is to use the Th1:Th2 paradigm and, thus, to propose to "dampen NK activity" in abortion prone women and this concept has been extended by some to implantation failure. We briefly review why the Th1:Th2 paradigms is no longer fully valid, describe briefly why it is inappropriate for implantation, and conclude that alloimmunisation should no longer be proposed for RSA, hence, more for implantation failure. We, however, do not reject immunotherapy, but we believe that molecular and cellular defects specific approaches should be used, tailored for the specific pathway whose disruption cause the clinical symptom.

Shall We properly Re-examine the Status of Allogeneic Lymphocyte Therapy for Recurrent early Pregnancy Failure?

PROBLEM

How to evaluate immunological therapy advocated for recurrent spontaneous abortion and implantation failure. I was invited to comment on the opinion article of Chaouat (AJRI December 2003).

METHODS

A critical examination of key beliefs and application of the principles of evidence and logic utilizing current data.

RESULTS AND CONCLUSIONS

Although rationale has no bearing on efficacy of proposed treatments and is not sufficient justification for routine practice, insufficient attention to data concerning patient selection, insufficient attention to treatment methodology, and lack of full disclosure in some clinical trials needs to be corrected. A more systematic collection of follow-up data is needed.

Immunotherapy for recurrent miscarriage

BACKGROUND

Immunologic aberrations might be the cause of recurrent early pregnancy loss in some women.

OBJECTIVES

The objective of this review was to assess the effects of leukocyte immunisation or other immunologic treatments such as intravenous immune globulin (IVIG) on the live birth rate in women with previous unexplained recurrent miscarriages.

SEARCH STRATEGY

The Cochrane Pregnancy and Childbirth Group trials register was searched (September 2002). Individual patient data were obtained from the American Society for Reproductive Immunology.

SELECTION CRITERIA

Randomised trials of immunotherapy in women with three or more prior miscarriages and no more than one live birth; all recognised non-immunologic causes ruled out and no simultaneous treatment intervention.

DATA COLLECTION AND ANALYSIS

Eligibility and trial quality were assessed by one reviewer.

MAIN RESULTS

Nineteen 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 immunisation (11 trials, 596 women), odds ratio (OR) 1.05, 95% confidence intervals (CI) 0.75 to 1.47; third party donor cell immunization (3 trials, 156 women), OR 1.39, 95% CI 0.68 to 2.82; trophoblast membrane infusion (1 trial, 37 women), OR 0.40, 95% CI 0.11 to 1.45; intravenous immune globulin (IVIG), OR 0.98, 95% CI 0.61 to 1.58.

REVIEWER'S CONCLUSIONS

Paternal cell immunization, third party donor leukocytes, trophoblast membranes, and intravenous immune globulin provide no significant beneficial effect over placebo in preventing further miscarriages.

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.

Prevention of transfusion-associated graft-versus-host disease by inactivation of T cells in platelet components

Patients with hematological malignancies and infants with congenital immunodeficiencies who received blood are two of many populations at risk for transfusion-associated graft-versus-host disease (TA-GVHD). Of the methodologies (eg, photoinactivation, peglyation, ultraviolet light, and irradiation) that can be used to prevent TA-GVHD, only irradiation of whole blood and cellular components is currently accepted practice of the US Food and Drug Administration (FDA). Among the newer methods that have been developed to reduce the risks of bacterial and viral contaminants of platelet transfusions, photochemical treatment (PCT) using psoralens and long-wavelength ultraviolet (UVA) irradiation modifies bacterial and viral genomes sufficiently to inhibit replication. Among a broad group of compounds, the synthetic psoralen compound amotosalen hydrochloride (HCl) (S-59) has been shown to be particularly effective in inactivating bacteria and viruses, without adversely affecting in vitro and in vivo platelet function.

Treatment of repeated unexplained in vitro fertilization failure with intravenous immunoglobulin: a randomized, placebo-controlled Canadian trial

OBJECTIVE

To evaluate the effect of intravenous immunoglobulin (IVIG) on pregnancy outcome in couples with repeated unexplained in vitro fertilization (IVF) failure.

DESIGN

Prospective, randomized, double blind, placebo-controlled clinical trial.

SETTING

A university-based and a free-standing IVF program.

PATIENT(S)

Fifty-one couples with a history of repeated unexplained IVF failure who were preparing for another fresh IVF cycle or replacement of cryopreserved embryos.

INTERVENTION(S)

Eligible women underwent a standard IVF stimulation using a long luteal phase GnRH analog protocol. Cryopreserved embryos were replaced after endometrial preparation with oral micronized estradiol and subsequent vaginal progesterone. The women were randomly selected to receive IVIG (500 mg/kg) or an equivalent volume of normal saline. The first infusion was given on the day of embryo transfer or during the preceding 72 hours. The second infusion was given 4 weeks later if a clinical pregnancy was confirmed by ultrasound.

MAIN OUTCOME MEASURE(S)

Live-birth rates.

RESULT(S)

Overall, the live-birth rates were 4/26 (15%) for the IVIG group and 3/25 (12%) for the placebo group (P=0. 52). There were 39 fresh IVF cycles, which yielded a clinical pregnancy rate of 28%, with live-birth rates of 4/21 (19%) for the IVIG group and 3/18 (17%) for the placebo group (P=0.59).

CONCLUSION(S)

In this randomized clinical trial, IVIG did not improve the live-birth rate in couples with repeated unexplained IVF failure, stringently defined by known determinants of IVF outcome.

Antibodies to phosphatidylethanolamine and phosphatidylserine are associated with increased natural killer cell activity in non-male factor infertility patients

Antiphospholipid antibodies (APA) have been identified in patients with recurrent pregnancy loss and IVF failure. Of these, antiphosphatidylethanolamine (aPE) and antiphosphatidylserine (aPS) may have special significance. A link between increased natural killer cell activity (NKa+) and trophoblast cell apoptosis has also been reported. This study was undertaken to determine how the APA profile was associated with peripheral NK cell activity. We evaluated 197 female IVF candidates for APA and NKa. Eighty-nine patients (45%) were APA+ and of these, 51 (57%) were aPE/aPS+. Fifty-four patients (27%) had increased NK cell activity. Some 51% of APA+ and 78% of aPE/aPS+ patients had increased NK cell activity compared with 8% and 13% when APA and aPE/aPS tested negative respectively (P: < 0.0001). Non-male factor infertility patients were APA+ and NKa+ in 57% and 34% of cases respectively, compared with 19% and 13% if a pure male factor was present. Some 88% of aPE/aPS+, non-male factor patients had increased NK cell activity, compared with 12% who tested aPE/aPS negative (P: < 0.0001) and 25% of aPE/aPS+, isolated male factor patients (P: < 0.0001). These findings establish a direct relationship between APA (specifically aPE/aPS) and increased peripheral NK cell activity among non-male factor infertility patients. It is possible that APA do not directly cause reproductive failure but rather function as markers or intermediaries for an underlying, abnormal activation of cellular immunity.

Human intravenous immunoglobulin preparation and virus inactivation by pasteurization and solvent detergent treatment

Human intravenous immunoglobulin (IVIG) solutions were prepared by two different methods and compared to each other. The crude immunoglobulin fraction obtained from Cohn-Oncley fractionation of plasma was further purified and subjected to virus inactivation, either by polyethylene glycol precipitation and pasteurization at 60 degrees C for 10 hours, or by ion exchange chromatography and solvent/detergent treatment. The final preparations, formulated in 5% immunoglobulin solutions were characterized by in vitro analyses of biochemical and biological properties and compared with the samples of other manufacturer's IVIG solution products. The critical properties evaluated in this study were purity, molecular intactness, and the biological functions such as Fc function and anticomplementary activity. Virus inactivation and removal by processing steps and by deliberate virucidal steps, as described above, were tested on various human pathogenic viruses, such as human immunodeficiency and experimental model viruses. The tested viruses were successfully inactivated and removed. We conclude that the intravenous immunoglobulins prepared by two different methods, as described above, provide an equivalent viral safety and quality.

Successful treatment of immunologic abortion with low-dose intravenous immunoglobulin

OBJECTIVE

To evaluate the efficacy of low-dose intravenous immunoglobulin (IVIG) treatment in older women with immunologic abnormalities and recurrent spontaneous abortion (RSA), a condition referred to as immunologic abortion.

DESIGN

Prospective clinical trial.

SETTING

Outpatient referral practice.

PATIENT(S)

Forty-seven women were enrolled in the study. The mean age of the women was 37 years (range, 28-45 years), and the mean number of prior miscarriages was 3.7. Immunologic abnormalities included antiphospholipid antibodies (32%), antithyroid antibodies (53%), antinuclear antibodies (28%), antiovarian antibodies (2%), increased natural killer cells (40%), increased immunoglobulin (Ig)M level (28%), and increased CD4/CD8 T-cell ratio (15%). One patient had IgA deficiency, and three women had endometriosis. Thirty-one of the 47 patients (66%) had more than one immunologic abnormality.

INTERVENTION(S)

Treatment with IVIG at a dose of 0.2 g/kg within 2 weeks of attempted conception. Once conception was achieved, IVIG treatment was continued on a monthly basis at the same dose through 26-30 weeks of gestation.

MAIN OUTCOME MEASURE(S)

Successful pregnancy or recurrent abortion.

RESULT(S)

Of the 47 women, 36 received initial IVIG treatment, and 24 subsequently became pregnant. Of these women, 20 continued IVIG treatment through 26-30 weeks of gestation, and 19 (95%) had a successful term pregnancy. Four women discontinued IVIG therapy after 10-12 weeks of gestation, and 3 (75%) had a successful pregnancy outcome. Of the 11 women who refused IVIG therapy, 7 became pregnant, and all 7 miscarried. The difference in pregnancy success rate between the IVIG-treated and untreated groups was significant (P=.001). Three women had adverse reactions during the low-dose IVIG infusion, and these reactions resolved when the IVIG brand was changed. Fetal abnormalities were not observed.

CONCLUSION(S)

Low-dose IVIG therapy is beneficial for older women with immunologic abortion. The optimum duration of IVIG treatment in these women requires further study.

Recurrent pregnancy loss: an update

This review highlights recent studies that investigate causes and treatments for recurrent pregnancy loss. Generally the causes of recurrent pregnancy loss are classified as genetic, endocrinologic, anatomic, immunologic, microbiologic, and environmental. The majority of recent work has focused on potential autoimmune and alloimmune causes; however, controversy still exists over appropriate testing and treatment. Reports have investigated the potential associations between autoimmune factors (antithyroid antibodies and antiphospholipid antibodies) and alloimmune factors (natural killer cells, cytotoxic T cells, and embryotoxic factors) and recurrent pregnancy loss. Increasingly, clinical reports are suggesting intravenous immunoglobulin as a potential treatment for these immunologic problems. Several lines of investigation have suggested certain hypercoagulable states as causative of recurrent pregnancy loss. New studies relating recurrent pregnancy loss to endocrinologic aberrations (hyperprolactinemia and hyperandrogenism) as well as social/environmental factors (stress, caffeine use, tobacco use, human immunodeficiency virus, and history of induced abortion) have been made. A summary of proposed evaluation and treatment options is presented.