Evidence of a T(H) 1 type response associated with recurrent miscarriage

Expression of SLAM as a functional and phenotypic marker in women with recurrent miscarriage

In the present work, we investigated the Th1 and Th2 cytokine patterns secreted by infiltrating endometrial lymphocytes from fertile women and from patients with recurrent spontaneous miscarriage (RSM). Moreover, we also analyzed the expression of cytokines in the whole endometrium from fertile and RSM women. Furthermore, we investigated the expression of the activation marker signaling lymphocytic activation molecule (SLAM) a cell surface glycoprotein expressed on lymphocytes that upon engagement boosts IFN-gamma production. Our results showed a slight increase in IL-10 expression in the endometrium of some fertile women, although no significant differences were found in IFN-gamma and IL-5 expression. In contrast, analysis of IFN-gamma production by polyclonal activated lymphocytes from endometrium and/or peripheral blood from fertile women showed a significant increase compared to RSM. Analysis of SLAM protein expression in luteal phase endometrial samples showed a significant increase in the levels of the receptor in RSM women compared to fertile women. These results correlated with a significant augmentation of SLAM levels in peripheral blood T-lymphocytes from RSM patients. Interestingly, after treatment of RSM patients with paternal mononuclear cells, surface-SLAM-expression in T-cells from RSM patients significantly decreased up to levels comparable to those of fertile women. Taken together, our results suggest that endometrial cells have not a defined pattern-cytokine-production under pre-implatatory conditions, and SLAM might be a potential marker for the diagnosis of RSM and an indicator useful to follow up the patient response to allogeneic immunotherapy.

TH1/TH2 paradigm in pregnancy: paradigm lost? Cytokines in pregnancy/early abortion: reexamining the TH1/TH2 paradigm

In this paper, we briefly survey the history of concepts in reproductive immunology from antibody-mediated tolerance to the "fetal allograft" to the current concept of an embryo "bathing in a sea of cytokines". We then review the paradigm that "allopregnancy is a Th2 phenomenon" and some of the evidence gained in animals and humans supporting it. We continue by discussing the light it sheds on immunologically caused recurrent abortion, and the present status of the concepts. We next show the limits of the Th1/Th2 paradigm by reviewing the role of "inflammatory" cytokines in implantation (as first seen with leukemia inhibitory factor). We go on to discuss recent data showing that interferon-gamma is not solely a "bad guy", e.g. abortifacient as the paradigm would predict, but is needed at low doses for the vascular development and transformation of uterine spiral arteries required for implantation and successful pregnancy. We conclude by discussing the emerging role of NK and IL-12, IL-15, IL-18 tripods and other cytokines in local angiogenesis and tissue remodelling, a series of new data bringing us well beyond the Th1/Th2 paradigm in pregnancy which, in this context, appears now obsolete and an oversimplification, although it has indeed been useful at first. Rather, step-specific events have to be considered and a key role is seen in local tissue remodelling, in which immune cytokines play an important role while not always being secreted by immune cells.

Effects of Interleukin-12 Administration during the Pre- and Peri-Implantation Period on Mouse Embryofetal Development

PROBLEM

The immunological success of pregnancy is thought to depend upon the establishment of a balance between favorable and deleterious cytokines, the current paradigm viewing pregnancy as a T helper (Th)2 cytokine-dependent phenomenon. In this context, a particular attention should be directed to the potential role of interleukin (IL)-12, which promotes the development of Th1 responses, in the induction of adverse pregnancy-related phenomena. Indeed, very few data linked the Th1-inducer IL-12 to the event of abortion.

METHODS

In this study, we have investigated the maternal and fetal effects of exogenous administration of IL-12 to CD1 (BR) ICR mice during the pre- and peri-implantation period (day 2-6 of pregnancy). Animals have been evaluated for parameters of reproductive performance, embryo and fetal developmental toxicity and maternal toxicity.

RESULTS

Intraperitoneal administration of IL-12 at concentrations from 2.5 to 10 microg/kg daily did not result in an increase in the murine abortion rate. A statistically significant, although minimal, decrease in the number of somites were found in the embryos of animals treated with IL-12 at a dose of 10 microg/kg/day. However, developmental parameters at birth were similar between the two groups of animals suggesting that alteration of somites might be a transitory state during treatment. An increased body weight gains and reduced feed and water consumption were observed in the mothers treated with the cytokine.

CONCLUSION

In the present experimental conditions and in this specific strain of mice, IL-12 does not exert adverse effects on reproductive performance and induces an only modest harmful action on mothers and embryos.

Uterine cavity matrix metalloproteinases and cytokines in patients with leiomyoma, adenomyosis or endometrial polyp

OBJECTIVE

To determine whether leiomyoma, adenomyosis and endometrial polyps are associated with changes in uterine cavity matrix metalloproteinases (MMP-2 and MMP-9) and cytokines.

STUDY DESIGN

Uterine cavity irrigation was performed in women with leiomyoma, adenomyosis and endometrial polyps, and in women with a normal uterus. MMP-2 and MMP-9 were assayed in the uterine washings by gelatin zymography. For individual subjects, the total MMP level was obtained by adding the semi-quantitative scores of band densities related to gelatinases in the zymograms. Interleukin-1beta (IL-1beta), tumor necrosis factor-alpha (TNF-alpha), interferon-gamma (IFN-gamma) and transforming growth factor-beta1 (TGF-beta1) were measured using enzyme-linked immunosorbant assay (ELISA) kits.

RESULTS

The uterine cavity of patients with leiomyoma, adenomyosis and endometrial polyps had significantly higher MMP scores than controls. Although the mean IL-1beta levels were elevated in uteri harboring a pathology compared with the normal uteri, the cytokine was significantly elevated only in the adenomyotic group. Significantly elevated levels of IFN-gamma were found in uteri with leiomyoma and endometrial polyps. Uterine washings from leiomyoma and adenomyosis contained significantly elevated mean levels of TGF-beta1 compared with controls, while TNF-alpha was significantly higher only in leiomyoma. When uterine cytokine levels were compared in relation to individual MMP levels a significant relationship was found between TGF-beta1 and elevated levels of MMP-9 and total MMPs in leiomyoma. A significant relationship was also found between IL-1beta and elevated levels of MMP-2, MMP-9 and total MMPs in the endometrial polyp group.

CONCLUSION

The uterine cavity in leiomyoma, adenomyosis and endometrial polyps contains elevated levels of MMPs and cytokines compared with the normal uterus. In some pathologies elevated cytokines are associated with elevated MMPs.

Proinflammatory and anti-inflammatory cytokines in pregnant women chronically infected with Trypanosoma cruzi

Mother-to-child transmission of intracellular parasites could be related to the production of immunoregulatory cytokines. The levels of gamma interferon (IFN-gamma), tumor necrosis factor-alpha (TNF-alpha) and lnterleukin (IL)-10 were evaluated during pregnancy in sera of women chronically infected with Trypanosoma cruzi that delivered infected or non-infected children. The levels of IL-10 increased in both, women only pregnant and only infected, compared to non-infected non-pregnant women. However, in pregnant women chronically infected with T. cruzi, IL-10 did not increase significantly, neither in the mothers of infected nor in the mothers of non-infected children. The levels of the inflammatory cytokine TNF-alpha were not affected in normal pregnancy but increased in the infected mothers of non-infected children. The levels of IFN-gamma did not increase in the groups studied, indicating that the production of this pro-inflammatory cytokine was controlled, even when the levels of IL-10 did not increase, as in pregnant women chronically infected with T. cruzi.

Lack of association of TNFα gene polymorphisms and recurrent pregnancy loss in Caucasian women

The tumor necrosis factor alpha (TNFalpha) gene plays an important role in immunology and inflammation. Variant alleles of TNFalpha are associated with altered RNA and serum protein levels in humans. Conflicting results have been obtained regarding the role of TNFalpha during pregnancy and recurrent pregnancy loss (RPL). This study investigated the relationship between RPL and two polymorphisms in the promoter of the TNFalpha gene (TNFalpha -308 and -863). Genotyping was performed in 168 RPL women and 212 ethnically matched healthy individuals. In addition, we performed analysis of TNFalpha serum protein levels. We demonstrate that neither the polymorphism -308 nor the polymorphism -863 of the TNFalpha gene is associated with RPL in Caucasian women. In addition, we did not find any association between TNFalpha serum levels and the occurrence of RPL in a subset of 36 RPL women and 36 healthy individuals. We conclude that TNFalpha polymorphisms and resting blood TNFalpha levels do not correlate with the propensity to recurrent pregnancy loss in Caucasian women.

T-helper 2-cytokine levels in women with threatened abortion

OBJECTIVE

Considering that successful embryo development has been immunologically attributed to a T-helper 2 phenomenon and that threatened abortion is a very frequent but pathogenetically not well-defined clinical entity, our purpose was to investigate serum levels of the main T-helper 2-type cytokines during the evolution of this condition.

STUDY DESIGN

Three T-helper 2-type cytokines (interleukin-6 (IL-6), interleukin-10 (IL-10), interleukin-13 (IL-13)) were measured by an enzyme-linked immunosorbent assay (ELISA) in serum of 12 women with threatened abortion both at hospital admission and discharge time. Fourteen women with missed abortion, 14 normal pregnant women and 14 normal non-pregnant women represent study control groups.

RESULTS

Serum concentrations of the selected T-helper 2-type cytokines showed no significant differences in women with threatened abortion with those of normal pregnant and non-pregnant women, whereas showed significantly lower values in women with missed abortion.

CONCLUSION

Our data (a) confirm the concept that first-trimester normal pregnancy is a T-helper 2 phenomenon, (b) show that threatened abortion, when T-helper 2-biased, may tend to a positive evolution of the condition, (c) display that interleukin-10, particularly, may represent a useful diagnostic and prognostic marker for predicting the normal continuance of the pregnancy in threatened abortion, (d) confirm the existence of a T-helper 2-type pattern deficiency in missed abortion, and finally (e) may open the way to new T-helper 2-biased immune therapies in case of difficult first-trimester pregnancies.

Abnormal First Trimester Serum Interleukin 18 Levels are Associated with a Poor Outcome in Women with a History of Recurrent Miscarriage

PROBLEM

How the maternal immune system adapts to tolerate the fetus is not fully understood, but a successful pregnancy is associated with the production of Th2-type cytokines and miscarriage is associated with the production of Th1-type cytokines.

METHOD OF STUDY

Levels of interferon (IFN)-gamma, interleukin (IL)-4, IL-12 and IL-18 were measured in serum from 205 pregnant women of whom 115 pregnant women had a history of recurrent miscarriage.

RESULTS

Compared with healthy pregnant women those who miscarried had increased serum levels of the Th1-associated cytokines IFN-gamma, IL-12 and IL-18.

CONCLUSIONS

Increased levels of IL-18 appeared to be critical in early pregnancy and were able to discriminate between pregnancies that continued and those that end in miscarriage.

Presence of interleukin-8 and the IL-1 receptor antagonist in the cervical mucus of fertile and infertile women

Background. Cytokines are involved in almost every aspect of reproduction and recent studies suggested a relationship between cytokines and male/female infertility. In the present study, the levels of interleukin-8 (IL-8) and interleukin-1 receptor antagonist (IL-1Ra) were determined in the cervical mucus of fertile and infertile women. Methods. Groups of patients were formed according to the results of the standard procedure for infertility investigation, including postcoital test and the presence of antispermatozoid antibodies in the sera of both partners and in seminal plasma, by mixed antiglobulin reaction (MAR) test and Kibrick agglutination test. IL-8 and IL-1Ra levels were determined in solubilized (ultrasonographic sonicaton) cervical mucus sampled in the midcycle by commercial ELISA kits and expressed as pg/mg proteins. Results. The groups were designated as fertile (n=20) and infertile (n=48). The latter was divided into two subgroups, one consisting of infertile women with positive postcoital test and without antispermatozoid antibodies (n=30), and the other designated as infertile women with negative postcoital test (n=18). This subgroup was composed of women with negative postcoital test and without antibodies (n=10) and the women with negative postcoital test with antibodies (n=8). Similar levels of IL-8 and IL-1 Ra were noted in the cervical mucus of in fertile women and women with positive postcoital test and without antispermatozoid antibodies. A tendency of decrease (p=0,052) and significant decrease in IL-8 levels (p<0.05) was noted in negative postcoital test group and negative postcoital test group without antibodies respectively, compared to the levels in the fertile examinees. A significant rise in IL-1Ra levels (p<0,05) was detected in the mucus of negative postcoital test group with further increase in negative postcoital test group with antibodies (p<0.02). Conclusion. Changes in IL-8 and IL-1 Ra levels in the cervical mucus of infertile patients with negative postcoital test suggested the existence of the relatinship between cervical cytokines and infertility in these women.

Fraction of the peripheral blood concentration of CD56+/CD16−/CD3− cells in total natural killer cells as an indication of fertility and infertility

OBJECTIVE

To determine whether the peripheral blood concentration of CD56(+)/CD16(-)/CD3(-) cells, the main natural killer (NK) subpopulation that colonizes the endometrium in the middle and late secretory phase, can be related to fertility or infertility status.

DESIGN

A case control study.

SETTING

Immunopathology department of an infertility laboratory.

PATIENTS

A total 99 women were selected (group I: consecutive spontaneous aborters, n = 25; group II: sporadic spontaneous aborters, n = 30; group III: infertile, n = 33; group IV: controls, n = 11).

INTERVENTION

Immunophenotyping of women grouped according to their fertility status.

MAIN OUTCOME MEASURES

Peripheral blood lymphocytes were examined by two- and three-color flow cytometry.

RESULTS

A statistically significant association between endometrial-type peripheral blood (PB) NK cell concentrations and fertility status (groups I and IV vs. groups II and III) was documented. The %(/TOTAL PB)(CD56+CD16-CD3-) NK cells was significantly higher [1] in fertile (groups I and IV) than in sporadic aborters/infertile (groups II and III) women, [2] in group I when compared with groups II and III, and [3] in group IV when compared with groups II and III.

CONCLUSIONS

This study indicates that diminished numbers of the %(/TOTAL PB)(CD56+CD16-CD3-) NK cells are related to sporadic aborters and infertile women. Thus, the fraction could be used as an indicator of subsequent successful implantation and maintenance of gestation.

Reproductive history and allergic rhinitis among 31145 Danish women

BACKGROUND AND OBJECTIVE

A successful pregnancy is associated with a strong skewing of the immune system towards a Th2-type immune response. Because such a deviation is also the hallmark of allergic disease, it was investigated whether allergic rhinitis in women was associated with an increased likelihood of becoming pregnant and having a successful outcome of pregnancies.

MATERIAL AND METHODS

Information on allergic rhinitis and reproductive history was obtained for 31145 pregnant women who participated in a national birth cohort study in Denmark during September 1997 to March 2000, and for whom complete information on siblings and place of residence and birth was available via the Civil Registration System. Data were analysed using logistic regression.

RESULTS

Women who had previously been pregnant (OR = 0.91, 95% CI 0.85-0.98) or who had given birth previously (OR = 0.91, 95% CI 0.85-0.98) were less likely to report allergic rhinitis than others. The number of previous spontaneous abortions, gestational week of the first spontaneous abortion and fertility treatment were not associated with allergic rhinitis. Women who had waited less than a year to become pregnant more often had allergic rhinitis (OR = 1.18, 95% CI 1.06-1.32, P = 0.002) than women who had waited for more than a year. Early age at menarche was associated with an increased likelihood of allergic rhinitis (Ptrend = 0.003).

CONCLUSIONS

Our findings did not support the hypothesis that an atopic genotype overall should be associated with an increased likelihood of successful outcome of pregnancies, but it might be associated with a decreased waiting time to pregnancy.

Associations between cytokine gene polymorphisms and recurrent pregnancy loss

Since certain cytokines may play a role in unexplained recurrent pregnancy loss (RPL) and also some cytokine gene polymorphisms may affect the level of cytokine production, the aim of the present study was to investigate the relationship between RPL and polymorphisms of the genes coding for TNF-alpha (-308 G-->A), IL-10 (-1082 G-->A), IL-6 (-174 G-->C), and IFN-gamma (+874 A-->T). Genotyping was performed in 48 RPL women and 108 ethnically matched healthy individuals. In addition, we performed a meta-analysis encompassing the present results and those from studies on the association of TNF-alpha, IL-10 and IFN-gamma polymorphisms with RPL published in the literature until December 2001. The results showed: (1) no evidence of association with IL-6 gene polymorphisms; (2) significant associations, revealed by the meta-analysis, with the high cytokine production genotypes of IFN-gamma (+874 T/T: odds ratio (OR)=1.92, P=0.04) and IL-10 (-1082 G/G: OR=1.75, P=0.03), and a trend for association with the high TNF-alpha production genotypes -308 A/A and A/G (OR=1.61; P=0.18). We believe that the associations of these genotypes with RPL are interesting not only as risk factors but also because they represent another piece of evidence that these cytokines might be important in the pathogenesis of RPL.

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.

High altitude residence during pregnancy alters cytokine and catecholamine levels

This study assessed the impact of high altitude residence during pregnancy on parameters of maternal immune and endocrine system function. Urinary catecholamines, and serum cytokines, estriol, and cortisol were assessed during pregnancy in women living at moderate or high altitude. Women residing at high altitude exhibited elevated levels of proinflammatory cytokines only during pregnancy, and tended to have higher levels of catecholamines during pregnancy than women living at lower altitude. These data suggest that the combination of high altitude and pregnancy alters the maternal neural-immune axis in a manner that may predispose women to suboptimal birth outcomes.

Some thoughts on the reproductive autoimmune failure syndrome (RAFS) and Th-1 versus Th-2 immune responses

PROBLEM

The concept of immunologically induced reproductive failure has remained very controversial. Especially the question whether abnormal immune function can cause infertility has recently been subject to strong disagreement. This opinion piece is an attempt to reconcile difference of opinion by integrating clinical data from the human experience with well-established experimental models in animals.

METHOD OF STUDY

Review of published literature.

RESULTS

Experimental animal data, especially in the mouse, have suggested that normal pregnancy requires a switch to an immune response with T helper (Th)-2 preponderance. Recent data from the human experience suggest that infertility, repeated pregnancy loss and certain complications of pregnancy may be the consequence of abnormal Th-1 preponderance. In analogy, to animal models, immunologic reproductive failure in humans, may therefore not be the consequence of specific autoantibody abnormalities or natural killer (NK)-cell abnormalities, but the reflection of a misdirection of a more broadly based immune response.

CONCLUSIONS

Under such a model, both diagnosis and treatment of immunologically induced forms of reproductive failure require re-evaluation. Such a model, however, provides a satisfactory explanation for contradictory findings in the human experience that have led to strong disagreements among investigations.

Differential expression of interleukins (IL) IL-13 and IL-15 throughout the menstrual cycle in endometrium of normal fertile women and women with recurrent spontaneous abortion

Interleukins (IL)-13 and IL-15 are novel cytokines and key regulators of immune/inflammatory related responses that are critical in the outcome of various normal biological and associated abnormalities of the endometrium. The present study determined the temporal and spatial expression of IL-13 and IL-15 mRNA and protein in endometrium of normal fertile women throughout the menstrual cycle, and examined whether profiles of their expression differ from endometrium of women with unexplained recurrent spontaneous abortion (RSA). Using quantitative RT-PCR, ELISA and immunohistochemistry we found that IL-13 and IL-15 mRNA and protein are expressed in control endometrium throughout the menstrual cycle and in RSA (cycle days 21-23) with peak expression detected immediately after and prior to onset of menses, and two distinct periods corresponding to late proliferative and the early-mid secretory phases, respectively. The ratio of IL-13:IL-15 expression revealed a predominance in IL-13 expression during late proliferative/early secretory phase and IL-15 during the mid secretory phase. Compared to control endometrium, endometrium of women with RSA expresses elevated levels of IL-13 and IL-15, with IL-13:IL-15 ratio favoring IL-13. The immunoreactive IL-13 and IL-15 were localized primarily in endometrial luminal epithelial cells with an increased intensity in glandular epithelial and stromal cells in RSA. In conclusion, the results indicate that endometrium of normal fertile women expresses IL-13 and IL-15, with a distinct profile during the menstrual cycle and elevated expression in women with RSA. Although the biological significance of IL-13 and IL-15 in human endometrium and their elevated expression in RSA await investigation, these cytokines with distinct biological functions may regulate endometrial inflammatory/immune responses, tissue repair and receptivity for embryo implantation.

The immunophenotype of patients with recurrent pregnancy loss

OBJECTIVE

The aim of the study was to estimate the alterations in the phenotype of lymphocytes of women with unexplained pregnancy failures in comparison with healthy women.

MATERIALS AND METHODS

Fourteen women with unexplained habitual miscarriages and 18 healthy, fertile women with the history of successful pregnancies were included in the study. The lymphocytes were isolated from peripheral blood and stained with monoclonal antibodies. The expression of selected surface molecules was estimated using the flow cytometric method.

RESULTS

We found that the percentage of T CD4(+) lymphocytes, CD3(-)16/56(+) cells, and T CD8(+)11b(-) cells was significantly higher in patients with recurrent pregnancy loss in comparison with healthy women. The percentage of B-1 CD19(+)5(+) lymphocytes was also significantly higher in women with unexplained habitual miscarriages in comparison with healthy women. Furthermore, we found higher expression of CD25 molecule on T CD3(+) and T CD4(+) lymphocytes in the study group, when compared to controls. Moreover, the percentages of B CD19(+) and T suppressor CD8(+)11b(+) lymphocytes were lower in women with pregnancy failures in comparison with the control group. The percentage of T CD3(+) lymphocytes and T CD8(+) cells did not differ in both studied groups. Similarly, the expression of CD25 antigen and HLA-DR molecule on T CD8(+) did not differ in the study group, when compared to controls.

CONCLUSION

Our results can suggest that the immunological alterations may be involved in the etiopathogenesis of unexplained recurrent pregnancy loss.

Distributions of endometrial NK cells, B cells, T cells, and Th2/Tc2 cells fail to predict pregnancy outcome following recurrent abortion

PROBLEM

To evaluate the ability of immunophenotypes of endometrial leukocytes from patients with histories of recurrent abortion to predict outcome of subsequent pregnancy.

METHODS OF STUDY

Seventeen women with two successive spontaneous abortions with normal karyotype in the conceptus and 15 women with male-factor infertility were studied. Subsequent pregnancy outcomes in 17 recurrent abortion patients were noted; 11 had live birth, while six aborted in the first trimester. All of 15 women with male-factor infertility became pregnant after therapy, resulting in live birth in all cases. Endometrium was sampled during the peri-implantation period before subsequent pregnancy. We immunostained paraffin-embedded sections for lymphocyte markers including natural killer (NK) cell markers, CD56 and CD16, a B-cell marker CD20, T-cell markers CD3 and CD8, and a specific T-helper(Th)2 and T-cytotoxic (Tc)2 marker termed 'chemoattractant receptor-homologous molecule expressed on Th2 cells' (CRTH2). Immunoreactive cells for these antigens were counted and positivity ratios to CD45- or CD3-positive cells were calculated. These parameter were compared between 17 patients with histories of recurrent abortion and 15 control women and also compared between 11 patients whose subsequent pregnancy was successful and six patients whose subsequent pregnancy was a failure.

RESULTS

Numbers of CD45+, CD56+, CD16+, CD20+, CD3+, CD8+, and CRTH2+ cells in recurrent abortion patients resembled those in controls. No significant difference in lymphocyte subset numbers or ratios was noted between patients whose subsequent pregnancy was successful and those who again aborted.

CONCLUSION

We could not predict pregnancy outcome by immunophenotypic analysis of endometrium in women with recurrent abortion.

Oral tolerance, systemic immunoregulation, and autoimmunity

Convincing clinical and experimental evidence suggests that the disturbance of important immunoregulatory and suppressive immunological events induced after oral (mucosal) antigen exposure (oral tolerance) may lead to allergic and autoimmune diseases. Within a variety of factors, age of the host and timing of antigen (food) administration are important characteristics in the development of food allergic disease. Induction of tolerance is seen as a Th2 skewed response, which on one side may prevent harmful mucosal immune reactions but on the other side may contribute to adverse responses in the susceptible individual. The primary mechanisms by which tolerance may be mediated include deletion, anergy, suppression, "ignorance," and apoptosis. Cell-mediated delayed hypersensitivity reactions (Th1), which are implicated in the development of autoimmune and gastrointestinal diseases, are particularly well suppressed. Regulatory events after mucosal exposure of antigen are not well characterized and remain controversial. The balance between tolerance (suppression) and sensitization (priming) is dependent on several factors, such as: (a) genetic background, (b) nature and dose of antigen, (c) frequency of administration, (d) age at first antigen exposure, (e) immunological status of the host, (f) antigen transmission via breast milk, and others. Overall there is evidence in rodents that multiple low-dose feeds are more likely to induce regulatory cytokines (e.g., TGF-beta, IL-10, IL-4) in part secreted by CD4+CD25+ T regulatory cells. Despite the powerful suppressive effects of oral autoantigen exposure observed in experimental models of autoimmune diseases (including bystander suppression), their translation into clinical trials of autoimmune diseases has not yet yielded the expected beneficial results.

Cytokine expression in peripheral blood lymphocytes indicates a switch to T(HELPER) cells in patients with preeclampsia

We sought to determine whether cytokine expression in peripheral blood mononuclear cells is altered in patients with preeclampsia and in patients with a history of recurrent spontaneous abortion (RSA). Twenty-four patients with preeclampsia and twenty patients with a history of RSA were included into the study. Two control groups consisted of twenty healthy pregnant and twenty healthy non-pregnant women. The intracellular expression of interleukin-2 (IL-2), interleukin-4 (IL-4) and interferon-gamma (IFN-gamma) were determined in peripheral blood mononuclear cells (PBMCs) by flow cytometry as a measure of cytokine production. IL-2 synthesis was significantly elevated in the third trimester in preeclamptic patients in comparison with the control group. Non-pregnant women with RSA showed a significantly lower expression of IFN-gamma compared to the non-pregnant control group. Our data suggest an abnormal immune response in preeclamptic patients characterised by a shift to a predominantly Th1-type immunity.

Immunity induced after a feed of antigen during early life: oral tolerance v. sensitisation

There is good clinical and experimental evidence that oral tolerance exists in man and that the timing of antigen (food) administration is an important factor in the development of food allergic sensitisation and disease. Induction of tolerance is often seen as a T-helper 2-skewed response, which on one side may prevent harmful mucosal immune reactions, but on the other side may contribute to adverse responses in the susceptible individual. The primary mechanisms by which tolerance may be mediated include T-cell deletion, anergy, suppression 'ignorance' and apoptosis. Cell-mediated delayed hypersensitivity reactions (T-helper 1), which are implicated as a pathogenetic principle in the development of autoimmune and gastrointestinal inflammation are particularly well suppressed. Regulatory events during the induction of tolerance (or sensitisation) are not well characterised and remain at times controversial. The balance between tolerance (suppression) and sensitisation (priming) is dependent on several factors, such as: (a) genetic background; (b) nature of antigen and dose of antigen; (c) frequency of administration; (d) age (maturity v. immaturity) at first antigen exposure; (e) immunological status of the host (e.g. virus infection); dietary exposure of the mother; (g) antigen transmission via breast milk, and others. Overall, there is evidence in rodents that multiple low-dose feeds are more likely to induce regulatory cytokines (e.g. transforming growth factor-beta, interleukins 10 and 4) in part secreted by CD4+CD25+ T-regulatory cells. Despite the powerful suppressive effect of oral antigen exposure observed in experimental models, its application in clinical trials of autoimmune diseases has not yet yielded the expected beneficial results.

Mouse oocytes and preimplantation embryos bear the two sub-units of interferon-gamma receptor

Cytokines and growth factors play important roles in implantation and maintenance of pregnancy, but also during early development. Among them interferon-gamma (IFNgamma) is highly expressed by mammalian trophoblast cells during implantation and seems to be involved in some cases of pregnancy loss. In the present study we investigated the possible presence of IFNgamma receptors (IFNGR) on mouse oocytes and preimplantation embryos. The two receptor chains IFNgammaRalpha (IFNGR-1) and IFNgammaRbeta (IFNGR-2) have been detected by indirect immunofluorescence at the surface of mouse oocytes (in germinal vesicle and metaphase II stages), as well as at all stages of in vitro embryo development from the one-cell to blastocyst stage. IFNGR appeared to colocalize partly with ganglioside GM1 at the cell surface of oocytes and embryos, indicating a possible preferential localization of this receptor in "rafts" microdomains. This was analyzed in more detail using software developed in the laboratory. IFNgamma was found to bind to its receptor at all stages analyzed. RT-PCR and Southern blot experiments confirmed the presence of the transcriptionally regulated IFNGR-2 chain mRNA, in mouse oocytes and preimplantation embryos. These results show, for the first time, that mouse oocytes and preimplantation embryos bear a complete and theoretically functional IFNGR, suggesting that this cytokine could play a role during early development.

Abnormal immunoglobulin subclass patterns in women with a history of recurrent miscarriage

OBJECTIVE

To determine whether IgG subclass patterns differed between nonpregnant women, healthy pregnant women, and pregnant women with a history of recurrent miscarriage.

DESIGN

Controlled clinical study.

SETTING

An academic setting.

PATIENT(S)

Group 1 was comprised of 10 nonpregnant women, group 2 of 10 healthy pregnant women, group 3 of eight pregnant women with a history of recurrent miscarriage and whose pregnancies on this occasion went to term, and group 4 of 10 women with a history of recurrent miscarriage whose pregnancies again failed later in the first trimester.

INTERVENTION(S)

None of the patients received any medication.

MAIN OUTCOME MEASURE(S)

Serum levels of total IgG and IgG 1, 2, 3, and 4.

RESULT(S)

The results obtained showed that normal pregnancy was associated with a significant increase in total IgG production and an increase in IgG subclasses 1, 2, and 3. Women with a history of miscarriage, but who had a successful pregnancy on this occasion, showed a similar pattern of IgG subclasses. Women with a history of miscarriage and whose pregnancy again ended in miscarriage showed a different IgG subclass pattern.

CONCLUSION(S)

Pregnancies that ended in miscarriage showed a different pattern of IgG subclasses than those that continued to term. The changes seen in immunoglobulin patterns could be linked to changes in cytokine production.

A model for potential tumor immunotherapy based on knowledge of immune mechanisms responsible for spontaneous abortion

Attempts to treat various cancers by immunotherapy have been tried for about 50 years. Most studies have focused on improving cytotoxic T lymphocyte (CTL) responses against various tumors. Immunotherapy has been both active and passive, and results have been modest at best. Spontaneous abortion (SAB) of pregnancies could in some ways resemble remission of a tumor. Both tumors and conceptusses are faced with a similar problem -- how to grow in a host in a vascular rich area, and yet escape immune surveillance despite both entities being an allogenic stimulus. In general, the fetus is far more immunogenic than a spontaneous tumor, and yet abortuses seem to avoid CTL responses but are sometimes invaded by natural killer (NK) cells. There are data suggesting that SAB will occur if there is inhibition of production of an immunosuppressive protein called progesterone-induced blocking factor (PIBF). This protein inhibits NK cell cytolysis and influences TH2 cytokine dominance over TH1. If some tumors avoid NK cell destruction through a PIBF mechanism, perhaps an active rejection of these tumors could be achieved by inhibiting PIBF production by treating with a progesterone receptor antagonist. Passive immunization could also be considered by conjugative radionuclide or toxic chemical to a PIBF antibody which may be tumor specific since PIBF is not produced in normal tissue. The first step should be to see if PIBF can be detected in the peripheral circulation in patients with certain tumors.

Oocyte comet assay of luteal phase sera from nonpregnant patients after assisted reproductive procedures

PURPOSE

Serum factors in patients with recurrent spontaneous abortions (RSA) inhibit mouse embryo development in vitro. Serum factors affecting DNA integrity remain to be tested. The null hypothesis was that patient sera do not affect DNA integrity. The objectives were (a) to use the oocyte comet assay to assess DNA damage after exposure to patient sera and (b) to determine the effect of sera from gravidity 0 parity 0 patients to induce DNA apoptosis.

METHODS

Luteal phase sera were drawn 1 week after embryo transfer following assisted reproductive procedures. Frozen-thawed hamster zona intact oocytes at metaphase II were incubated in groups of eight in either control medium or medium supplemented with 50% patient serum for 1.5 h at 37 degrees C in room air. The oocytes were fixed, stained in acridine orange, embedded in agarose, lysed, and alkaline electrophoresis performed. The intensities of the digitized fluorescent images were analyzed.

RESULTS

The sera of nonpregnant patients (64%) caused significant fragmentation of hamster oocyte DNA when compared with pregnant patient sera. This difference was also observed when adjusted for patient age. Sera of patients that had never been pregnant also resulted in oocyte DNA fragmentation.

CONCLUSIONS

The results suggested that sera from patients that did not conceive contained factors that did not support cell growth by causing DNA fragmentation and apoptosis. The level of the apoptotic factors varied from cycle to cycle. However, more studies are needed to determine if the sera factors actually reach the uterine environment to cause the undesirable effects.

A polymorphism of the interleukin-1beta gene and idiopathic recurrent miscarriage

OBJECTIVE

Proinflammatory cytokines have been described to be involved in the pathogenesis of idiopathic recurrent miscarriage (IRM). We investigated the association between IRM and a polymorphism in exon 5 of the interleukin-1beta gene (IL1B) and interleukin-1beta (IL-1beta) serum levels.

DESIGN

Case control study.

SETTING

Academic research institution.

SUBJECTS

One hundred thirty-one women with a history of three or more consecutive pregnancy losses before 20 weeks' gestation and 68 healthy controls with at least two live births and no history of pregnancy loss.

INTERVENTIONS

Peripheral venous puncture.

MAIN OUTCOME MEASURES

An IL1B exon 5 (position +3953) gene polymorphism was analyzed by PCR amplification followed by restriction fragment length polymorphism analysis. IL-1beta serum levels were analyzed by a commercially available ELISA.

RESULTS

Allele frequencies in women with IRM and controls were 77.9% and 80.8%, respectively, for the E1 allele (wild type), and 22.1% and 19.2%, respectively, for the E2 allele (mutant). No association between the E2 allele and the occurrence of IRM was found (P=.57, odds ratio =.83). Genotype frequencies and IL-1beta serum levels were not significantly different between the study group and the control group.

CONCLUSIONS

This is the first report on an IL1B polymorphism in IRM. Although known to alter IL-1beta expression, the investigated IL1B polymorphism is not associated with IRM and increased serum levels in a large Caucasian population.

Interleukin 1 receptor antagonist polymorphism in women with idiopathic recurrent miscarriage

OBJECTIVE

Proinflammatory cytokines have been described as etiologic factors in idiopathic recurrent miscarriage. We investigated the relation between idiopathic recurrent miscarriage and polymorphisms in the gene encoding for the interleukin 1 receptor antagonist, an indigenous modulator of proinflammatory immune response.

DESIGN

Prospective case control study.

SETTING

Academic research institution.

PATIENT(S)

One hundred five women with a history of three or more consecutive pregnancy losses before 20 weeks of gestation and 91 healthy, postmenopausal controls with at least two live births and no history of pregnancy loss.

INTERVENTION(S)

Peripheral venous puncture.

MAIN OUTCOME MEASURE(S)

Polymerase chain reaction was performed to identify the different alleles of the gene encoding for interleukin 1 receptor antagonist.

RESULT(S)

Allele frequencies among women with idiopathic recurrent miscarriage and controls were 0.34 and 0.11, respectively, for the polymorphic allele 2 (P=.002; odds ratio: 7.4, confidence interval: 2.9--10.8) and.05 and.05, respectively, for the polymorphic allele 3 (P=.6; odds ratio: 1.3, confidence interval: 0.8--2.3). Allele 2 was present in homozygous form in 9% of women with idiopathic recurrent miscarriage. In contrast, 1% of the control women were homozygous for this allele (P<.001; odds ratio: 13.5, confidence interval: 7.5--21.8).

CONCLUSION(S)

These data support a role for allele 2 of the gene encoding for interleukin 1 receptor antagonist as genetic determinant of idiopathic recurrent miscarriage.

Antioxidants: their role in pregnancy and miscarriage

The aim of this study was to examine the role of antioxidants within the normal menstrual cycle, in healthy pregnancy, and in women suffering first-trimester miscarriage. The antioxidants chosen comprised of two from peripheral blood-plasma thiol and ceruloplasmin-and two extracellular parameters-superoxide dismustase (SOD) and red cell lysate thiol. We found that antioxidant levels varied little throughout the menstrual cycle. Pregnancies that went successfully to term were associated with increased levels of ceruloplasmin and SOD early in the first trimester. These changes were thought to offer the cell protection from the damage caused by the increased oxidative stress associated with pregnancy. First-trimester miscarriage was associated with significantly reduced levels of SOD. A subgroup of patients who miscarried in their first pregnancy, but whose second pregnancies were successful, had higher levels of plasma thiol and significantly reduced levels of red cell lysate thiol in the on-going pregnancy compared to levels at the time of miscarriage. Miscarriage and pregnancy appear to be associated with increased oxidative stress. In a successful pregnancy, however, changes occurred within the peripheral blood that offered protection from oxidant attack.