Association between Genetic Polymorphisms in Interleukin Genes and Recurrent Pregnancy Loss - A Systematic Review and Meta-Analysis

Association of Interleukin-17A rs2275913 Polymorphism with Recurrent Miscarriage: A Systematic Review and Meta-Analysis Study

Recurrent miscarriage (RM) is a condition defined as having three or more consecutive pregnancy losses before the 20 weeks of pregnancy. The present study was undertaken to investigate association of Interleukin-17A (IL-17A) rs2275913 polymorphism with RM. To this end, we searched the international databases (Web of Science, PubMed, Embase, and Scopus) and extracted studies investigating the association of IL-17A rs2275913 polymorphism with RM using the appropriate keywords. The collected data were analyzed with the random-effects model and STATA (version 14). A total of five studies met the eligibility criteria, and total sample size was 998 subjects. Mean age of the cases and controls were 31.41 ± 4.16 and 30.56 ± 3.5 years, respectively. Our results disclosed a significant relationship of the IL-17A rs2275913 AA genotype [odds ratio (OR)=1.68; 95% confidence interval (CI)=1.16- 2.43; I2=19; P=0.294) with RM. There was no statistically significant correlation between IL-17Ars2275913 GG genotype (OR=1.04; 95% CI=0.64-1.7; I2=59.5; P=0.042) and GA genotype (OR=0.85; 95% CI=0.65-1.12; I2=19.1; P=0.293) with RM. Our findings revealed that the IL-17A rs2275913 polymorphism is associated with RM, and the AA genotype of this polymorphism increased possibility of being involved in RM.

Impact of Interleukin-10 Promoter Region Polymorphisms on Recurrent Miscarriage: A Case-Control Approach

Background

Recurrent miscarriage (RM), defined as two or more consecutive miscarriages prior to the 20th week of gestation is characterised by multifactorial aetiology. The prevalence of RM varies from 0.8% to 13.5% amongst women of reproductive age. The aetiological basis of RM has been traced to chromosomal, anatomic, hormonal and immunologic factors while half of the cases remain idiopathic.

Aims

This study aimed to investigate the association of interleukin-10 (IL-10) polymorphisms with RM amongst the Indian population.

Settings and Design

The present study included a total of 414 individuals including RM women (n = 199) with two or more pregnancy losses and healthy women (n = 215) without any previous history of pregnancy loss were taken as the control group.

Materials and Methods

Demographic features and reproductive history of women with RM and healthy women were taken. Genotype analysis of IL-10 polymorphisms rs1800872 and rs1800896 was performed using the polymerase chain reaction (PCR) restriction fragment length polymorphism and amplification mutation refractory system PCR, respectively.

Statistical Analysis Used

Student's t-test was used to compare the demographic features and reproductive history amongst both groups. Pearson's Chi-square was used to calculate the Hardy-Weinberg equilibrium, allelic and genotypic frequencies. All the statistical analyses were performed using the SPSS (version 21, IBM SPSS, NY, USA).

Results

Our results suggested that the genotypic and allelic frequency of rs1800872 polymorphism did not differ significantly between RM cases and control women (P = 0.07 and P = 0.23, respectively). The GG genotype (P = 0.007) and G allele (P = 0.003) of rs1800896 were significantly associated with an increased risk of RM. A statistically significant difference was also found for the distribution of genetic models (dominant and co-dominant model) between both groups for rs1800896. However, haplotype analysis revealed that none of the haplotypes provides a risk for the progression of RM.

Conclusion

The study is the first of its kind from our region and provides baseline data on the genetics of RM.

The Progress of Research on Genetic Factors of Recurrent Pregnancy Loss

Recurrent pregnancy loss (RPL) is both mental and physical health problem affecting about 1-5% of women of childbearing age. The etiology of RPL is complex, involving chromosomal abnormalities, autoimmune diseases, metabolic disorders, and endometrial dysfunction. The causes of abortion are still unknown in more than 50% of these cases. With the development of science and technology, an increasing number of scholars focus on this field and find that genetic factors may play an essential role in unexplained RPL, such as embolism-related genes, immune factor-related genes, and chromosomal numeric, and structural variation. This review summarizes the genetic factors associated with RPL, including genetic mutations and genetic polymorphisms, chromosomal variants, and chromosomal polymorphisms. Many related genetic factors have been found to be demographically and geographically relevant, some of which can be used for risk prediction or screening for the etiology of RPL. However, it is difficult to predict and prevent RPL due to uncertain pathogenesis and highly variable clinical presentation. Therefore, the genetic factors of RPL still need plentiful research to obtain a more accurate understanding of its pathogenesis and to provide more detection means for the screening and prevention of RPL.

Temporal changes in cyclinD-CDK4/CDK6 and cyclinE-CDK2 pathways: implications for the mechanism of deficient decidualization in an immune-based mouse model of unexplained recurrent spontaneous abortion

BACKGROUND

Deficient endometrial decidualization has been associated with URSA. However, the underlying mechanism is poorly understood. This study aimed to investigate the temporal cytokine changes and the involvement of CyclinD-CDK4/6 and CyclinE-CDK2 pathways in the regulation of the G1 phase of the cell cycle during decidualization in a murine model of URSA.

METHODS

Serum and decidual tissues of mice were collected from GD4 to GD8. The embryo resorption and abortion rates were observed on GD8 and the decidual tissue status was assessed. In addition, PRL, Cyclin D, CDK6, CDK4, Cyclin E, CDK2 expression in mice were measured.

RESULTS

URSA mice showed high embryo resorption rate and PRL, Cyclin D, Cyclin E CDK2, CDK4, CDK6 down-regulation during decidualization. The hyperactivated Cyclin D-CDK4/CDK6 and cyclin E/CDK2 pathways inhibit the decidualization process and leading to deficient decidualization.

CONCLUSION

Insufficient decidualization is an important mechanism of URSA. which is related to the decrease of Cyclin D、Cyclin E、 CDK2、CDK4 and CDK6 in decidualization process of URSA.

The Role of Interleukin in Ectopic Pregnancy: A Systematic Review

BACKGROUND: Ectopic pregnancy (EP) is the implantation of an embryo outside the eutopic cavity with the most location of EP is in the fallopian tube (FT), known as tubal EP (TEP). The FT of TEP expresses higher levels of pro-inflammatory cytokines such as interleukin-1 (IL-1), IL-6, and IL-8. AIM: The study aimed to look systematically into the current literature and carefully analyze the results to explore the role of IL in EP. METHODS: Three independent reviewers conducted the literature search through some electronic databases searching for articles fulfilling inclusion and exclusion criteria. The lead author independently assessed the risk of bias of each of the 313 articles identified in database searching, 12 articles met the criteria for this review. CONCLUSION: IL-6 and IL-8 have diagnostic significance in predicting EP with the cutoff levels of IL-6 and IL-8 which were 26.48 and 40 pg/mL. Further, research is needed for the role of other interleukins in EP.

Are genetic variations in IL-1β and IL-6 cytokines associated with the risk of pre-eclampsia? Evidence from a systematic review and meta-analysis

OBJECTIVE

This systematic review and meta-analysis study was performed to assess the potential association between interleukin-1 beta (IL-1β) single nucleotide polymorphisms (SNPs) (rs1143634 and rs16944) and interleukin-6 (IL-6) SNP (rs1800795) and pre-eclampsia (PE).

METHODS

A comprehensive literature search was conducted in the international search engines and databases, including MEDLINE (via PubMed), Scopus, and Web of Science (ISI) up to 9 March 2021. After retrieving relevant articles, data extraction was performed by four authors independently. Pooled ORs and corresponding 95% CIs were used to evaluate the association between IL-1β and IL-6 polymorphisms and PE risk. Cochran's Q test was used to check heterogeneity, and the I² index was calculated for measuring the heterogeneity between the estimations of included studies.

RESULTS

After reviewing fully published studies, 21 studies were included in this study based on the eligibility criteria. Our results showed that rs16944 and rs1143634 of IL-1β were significantly associated with the risk of PE. Regarding rs16944, the minor C allele significantly decreased the risk of PE (C vs. T: OR = 0.79, 95% CI = 0.69-0.90). In contrast, the minor T allele of rs1143634 significantly increased the risk of PE (T vs. C: OR = 1. 28, 95% CI = 1.04-1.58). There was no significant association between IL-6 rs1800795 (C vs. G: OR = 1.04, 95% CI = 0.93-1.16) polymorphism and PE risk.

CONCLUSIONS

In conclusion, this meta-analysis suggests rs1143634 and rs16944 polymorphisms of IL-1β are related to the risk of PE.

The Role of TNF-α and Anti-TNF-α Agents during Preconception, Pregnancy, and Breastfeeding

Tumor necrosis factor-alpha (TNF-α) is a multifunctional Th1 cytokine and one of the most important inflammatory cytokines. In pregnancy, TNF-α influences hormone synthesis, placental architecture, and embryonic development. It was also shown that increased levels of TNF-α are associated with pregnancy loss and preeclampsia. Increased TNF-α levels in complicated pregnancy draw attention to trophoblast biology, especially migratory activity, syncytialisation, and endocrine function. Additionally, elevated TNF-α levels may affect the maternal-fetal relationship by altering the secretory profile of placental immunomodulatory factors, which in turn affects maternal immune cells. There is growing evidence that metabolic/pro-inflammatory cytokines can program early placental functions and growth in the first trimester of pregnancy. Furthermore, early pregnancy placenta has a direct impact on fetal development and maternal immune system diseases that release inflammatory (e.g., TNF-α) and immunomodulatory factors, such as chronic inflammatory rheumatic, gastroenterological, or dermatological diseases, and may result in an abnormal release of cytokines and chemokines in syncytiotrophoblasts. Pregnancy poses a challenge in the treatment of chronic disease in patients who plan to have children. The activity of the disease, the impact of pregnancy on the course of the disease, and the safety of pharmacotherapy, including anti-rheumatic agents, in pregnancy should be considered.

Relationship between common interleukin 1-beta gene polymorphisms and the risk of gestational disorders: An updated meta-analysis

Background: To quantitatively estimate the relationship between IL-1β -511C>T, -31T>C, and +3954C>T polymorphisms and risk of gestational disorders. Methods: In this meta-analysis, eligible publications were searched in Web of Knowledge, MEDLINE, PubMed, Scopus, and Google Scholar databases (updated April 2020), using appropriate or relevant keywords. Case-control population-based reports were included if provided with genotypic frequencies of both studied groups. Statistical analyses were performed using the MetaGenyo web tool software, where a P value less than 0.05 indicated a significant association. For the assessment of between-study variations, heterogeneity analysis was applied with the I² statistics. Results: A total of thirteen studies were included. We observed a significant association between IL-1β-31T>C polymorphism and reduced risk of gestational disorders under codominant CT vs. CC [OR= 0.74, CI (0.59-0.92)], and dominant CT+TT vs. CC [OR= 0.74, CI (0.60-0.91)] contrasted genetic models. The stratified analysis considering the disease type showed that the 511C>T variant, under the recessive CC vs. CT+TT model, enhanced the risk of preterm birth by 1.29 fold. Conclusion: Our results failed to support an association between two IL-1β polymorphisms, 511C>T and +3954C>T, with the overall risk of gestational disorders. In contrast, the 31T>C variant reduced the incidence of such diseases. Further studies are encouraged to get more precise estimates of effect sizes.

Interleukin-1 beta is significantly upregulated in the decidua of spontaneous and recurrent miscarriage placentas

BACKGROUND

Pregnancy is an extraordinarily complex immunological process. For successful pregnancy maintenance the maternal immune system must adapt to and tolerate the semi-allogenic fetus at the fetomaternal interface of the placenta. This balance is regulated by cytokines with a predominant T helper 2 (Th-2) system and a suppressed inflammatory T helper 1 (Th-1) response. This study investigates the role of the Th-1 pro-inflammatory cytokine Interleukin-1 beta (IL-1β) and its role in early pregnancy loss.

PATIENTS AND METHODS

In order to identify differences in IL- β levels a TaqMan® Human Cytokine Network Array, with placental tissue obtained from patients with healthy pregnancies (n = 15) and recurrent miscarriage (n = 15), was carried out. Protein expression of IL-1β in the decidua of healthy pregnancies (n = 15), spontaneous (n = 18) and recurrent miscarriages (n = 15), was investigated by immunohistochemistry. The identification of IL-1β expressing cells in the decidua was done with double-immunofluorescence.

RESULTS

Gene expression analysis identified a nearly 54-times higher expression of IL-1β in placental tissue of patients suffering from recurrent abortion. Immunohistochemistry confirmed a significant upregulation of IL-1β in the decidua of recurrent miscarriage specimens (p = 0.01) as well as in the decidua of women with spontaneous abortion (p = 0.001). Double-immunofluorescence identified decidual stoma cells as IL-1β expressing cells.

CONCLUSION

Significant upregulation of IL-1β may be associated with an imbalanced immune system and a procoagulant state that could be responsible for early pregnancy loss. These results provide new evidence of the complex interplay of IL-1β at the fetomaternal interface and its crucial role in miscarriage processes.

Association of Promoter Region Polymorphisms of IL-6 and IL-18 Genes with Risk of Recurrent Pregnancy Loss: A Systematic Review and Meta-Analysis

Background: The present meta-analysis was performed to investigate the association of promoter region polymorphisms at IL-6 and IL-18 genes with recurrent pregnancy loss (RPL) risk. Methods: An electronic search of the PubMed, Embase, ISI Web of Knowledge and CNKI databases was performed to identify eligible studies up to May 30, 2019. Results: A total of 31 case-control studies were finally selected. Significant associations with the risk of RPL were detected for the IL-6 -174 G > C, -634 G > C and IL-18 -137 G > C polymorphisms in overall population. Further, subgroup analyses by ethnicity revealed that the IL-6 -174 G > C and -634 G > C polymorphisms were significantly associated with risk of RPL risk in Asians. Conclusions: Our results suggest that the IL-6 -174 G > C, -634 G > C and IL-18 -137 G > C polymorphisms may contribute to the susceptibility of RPL. The IL-18 -607 C > A polymorphism does not appear to influence the development of RPL.

The role of the IL-1 system in pregnancy and the use of IL-1 system markers to identify women at risk for pregnancy complications†

The interleukin (IL)-1 system plays a major role in immune responses and inflammation. The IL-1 system components include IL-1α, IL-1β, IL-1 receptor type 1 and IL-1 receptor type 2 (decoy receptor), IL-1 receptor accessory protein, and IL-1 receptor antagonist (IL-1Ra). These components have been shown to play a role in pregnancy, specifically in embryo-maternal communication for implantation, placenta development, and protection against infections. As gestation advances, maternal tissues experience increasing fetal demand and physical stress and IL-1β is induced. Dependent on the levels of IL-1Ra, which regulates IL-1β activity, a pro-inflammatory response may or may not occur. If there is an inflammatory response, prostaglandins are synthesized that may lead to myometrial contractions and the initiation of labor. Many studies have examined the role of the IL-1 system in pregnancy by independently measuring plasma, cervical, and amniotic fluid IL-1β or IL-1Ra levels. Other studies have tested for polymorphisms in IL-1β and IL-1Ra genes in women experiencing pregnancy complications such as early pregnancy loss, in vitro fertilization failure, pre-eclampsia and preterm delivery. Data from those studies suggest a definite role for the IL-1 system in successful pregnancy outcomes. However, as anticipated, the results varied among different experimental models, ethnicities, and disease states. Here, we review the current literature and propose that measurement of IL-1Ra in relation to IL-1 may be useful in predicting the risk of poor pregnancy outcomes.

Regulatory B Cells Are Decreased and Impaired in Their Function in Peripheral Maternal Blood in Pre-term Birth

Preterm birth (PTB) is defined as birth before 37 completed weeks of gestation. The causes of PTB are multiple and complex, the underlying pathophysiology being largely unknown. Interferences in the fine-tuned balance of the maternal immune system have been pointed to as one possible cause of PTB. Regulatory B cells (Breg) are part of the adaptive immune response, and recent data suggest that they may contribute to a healthy pregnancy by their regulatory/suppressive function. We investigated the frequency of Breg cells in peripheral blood of women undergoing PTB and control women immediately before giving birth via cesarean section. We detected an enhanced number of B cells, but a reduced number of Breg cells in women delivering preterm. In addition, the percentage of IL-10-producing B cells was decreased in PTB following stimulation with TLR agonists CpG or LPS, alone or combined with CD40L. This was associated with increased levels of pro-inflammatory cytokines in maternal serum. Moreover, isolated maternal B cells before delivering premature babies secreted higher level of the pro-inflammatory cytokine IL-6. No alterations in the frequency of regulatory T cells were found. Our data indicate that alterations in the number and function of Breg cells in peripheral maternal blood contribute to the immunological changes observed in preterm delivery and suggest these cells as important regulators of maternal immune responses.

Phosphorylated STAT3 inhibited the proliferation and suppression of decidual Treg cells in unexplained recurrent spontaneous abortion

This study aimed to investigate the effects of signal transducer and activators of transcription 3 (STAT3) phosphorylation on the function of decidual regulatory T (Treg) cells in unexplained recurrent spontaneous abortion (URSA) patients and to explore the mechanism of STAT3 in URSA. Treg cells were sorted out from the decidual tissue by magnetic beads. The inhibitor Stattic was utilized to alter the phosphorylation status of STAT3 (pSTAT3) in Treg cells. The proliferation and suppression of Treg cell were detected by flow cytometry, real-time quantitative fluorescent PCR and ELISA. The factors that caused the hyperphosphorylation of Treg cells were detected. Our results showed that the proportion of pSTAT3 cells in the decidual Treg cells of URSA patients was significantly increased. pSTAT3 inhibited the proliferation of Treg cells by downregulating the expression of STAT5 and Foxp3 and increased the number of responder T cells. pSTAT3 decreased the secretion of TGF-β1 and IL-10 in Treg cells. Overexpression of pro-inflammatory cytokines IL-6 and IL-23 stimulated STAT3 phosphorylation in Treg cells. This study suggests that hyperphosphorylation of STAT3 impairs the proliferation, suppression and cytokine secretion of Treg cells, while inhibiting the phosphorylation of STAT3 restores these functions. These findings clarify the role of STAT3 in the pathogenesis of URSA and provide new ideas for the treatment of URSA.

Analysis of the frequency of type 2 innate lymphoid cells and regulatory T cells in abortion-prone mice

Recurrent spontaneous abortion (RSA) is the most common pregnancy related complication, affecting 1-5 % of pregnancies. Despite hormonal, genetic and anatomical factors that result in abortion, impairment of immune response at the feto-maternal interface during the first trimester of pregnancy is also one of the main causes of RSA. In the present study, we evaluated the frequency of blood and uterine group 2 innate lymphoid cells (ILC2s), their subsets and regulatory T cells (Tregs) in CBA/J × DBA/2 J as an abortion-prone model compared to normal pregnant (NP) mice using immunophenotyping. Results indicated that the percentages of ILC2s were significantly decreased in the AP group compared to the NP group at mid-gestation (P ≤ 0.01). Moreover, the percentages of both blood and uterine nILC2s were increased in NP mice at mid-gestation (P ≤ 0.01, and P ≤ 0.05, respectively), while iILC2s significantly increased in AP mice at mid-gestation (P ≤ 0.01, and P ≤ 0.05, respectively). Tregs were reduced in AP mice at both early and mid-gestation stages (P ≤ 0.01). Overall, our findings suggest that the changes in blood and uterine ILC2s might be associated with abortion in mice.

Asthma and/or hay fever as predictors of fertility/impaired fecundity in U.S. women: National Survey of Family Growth

This study addresses whether asthma and/or hay fever predict fertility and impaired fecundity. The lifetime number of pregnancies (fertility) and spontaneous pregnancy losses (impaired fecundity) in 10,847 women representative of the U.S. population 15 to 44 years of age with histories of diagnosed asthma and/or hay fever are analyzed in the 1995 National Survey of Family Growth using multivariable Poisson regression with multiple covariates and adjustments for complex sampling. Smokers have significantly increased fertility compared to nonsmokers. Smokers with asthma only have significantly increased fertility compared to other smokers. Higher fertility is associated with impaired fecundity (ectopic pregnancy, miscarriage, stillbirth). Women with asthma (with and without hay fever) have significantly higher pregnancy losses than women without asthma. With increasing number of pregnancies, smokers have increased pregnancy losses compared to nonsmokers. Smokers, especially those with asthma only, have increased fertility and require special attention as to their family planning needs, reproductive health, and smoking cessation. Women with asthma, regardless of number of pregnancies, and smokers with higher numbers of pregnancies have high risk pregnancies that require optimal asthma/medical management prenatally and throughout pregnancy. Whether a proinflammatory asthma endotype underlies both the increased fertility and impaired fecundity associated with age and smoking is discussed.

The lncRNA SOX2OT rs9839776 C>T Polymorphism Indicates Recurrent Miscarriage Susceptibility in a Southern Chinese Population

Genetic susceptibility may be involved in the onset of recurrent miscarriage. Previous studies have shown that some genetic polymorphisms that regulate cell migration are associated with susceptibility to recurrent miscarriage. The SOX2 overlapping transcript (SOX2OT) may regulate the migration and invasion of multiple tumor cells and is related to susceptibility to various diseases. However, whether lncRNA SOX2OT polymorphisms are related to recurrent miscarriage susceptibility is unclear. Therefore, we investigated the relationship between the lncRNA SOX2OT rs9839776 C>T polymorphism and recurrent miscarriage susceptibility. We recruited 570 subjects with recurrent miscarriage and 578 healthy control subjects from a population in southern China and used the TaqMan method for genotyping. We found a significant association between the rs9839776 CT genotype in the SOX2OT gene and an increased risk for recurrent miscarriage (CT vs CC: adjusted OR = 1.357, 95%CI = 1.065 - 1.728, P = 0.0134). However, we did not observe any significant associations between the recurrent miscarriage risk and the number of miscarriages in different age groups. In conclusion, our study indicated that the rs9839776 CT genotype may contribute to an increased risk of recurrent miscarriage in the southern Chinese population and that rs9839776 may act as a prognostic biomarker in recurrent miscarriage patients. However, an experiment-based study with a larger sample size should be performed to confirm these results.

Endometrial Immune Dysfunction in Recurrent Pregnancy Loss

Recurrent pregnancy loss (RPL) represents an unresolved problem for contemporary gynecology and obstetrics. In fact, it is not only a relevant complication of pregnancy, but is also a significant reproductive disorder affecting around 5% of couples desiring a child. The current knowledge on RPL is largely incomplete, since nearly 50% of RPL cases are still classified as unexplained. Emerging evidence indicates that the endometrium is a key tissue involved in the correct immunologic dialogue between the mother and the conceptus, which is a condition essential for the proper establishment and maintenance of a successful pregnancy. The immunologic events occurring at the maternal-fetal interface within the endometrium in early pregnancy are extremely complex and involve a large array of immune cells and molecules with immunoregulatory properties. A growing body of experimental studies suggests that endometrial immune dysregulation could be responsible for several, if not many, cases of RPL of unknown origin. The present article reviews the major immunologic pathways, cells, and molecular determinants involved in the endometrial dysfunction observed with specific application to RPL.

The lncRNA CCAT2 rs6983267 G allele is associated with decreased susceptibility to recurrent miscarriage

Genetics might play various roles in susceptibility to recurrent miscarriage, and previous studies suggest that some gene polymorphisms might be associated with abortion and breast cancer onset. Colon cancer-associated transcript 2 (CCAT2) is a novel long noncoding RNA (lncRNA) transcript that might be correlated with susceptibility to multiple cancers, including breast cancer. However, whether lncRNA CCAT2 polymorphisms are related to susceptibility to recurrent miscarriage is unclear. We genotyped two lncRNA CCAT2 polymorphisms (rs6983267 and rs3843549) in 248 patients with recurrent miscarriage and 392 controls through a TaqMan real-time polymerase chain reaction assay, and the strength of each association was evaluated via 95% confidence intervals (CIs) and odds ratios (ORs). Our results showed that the rs6983267 G allele in lncRNA CCAT2 was associated with decreased susceptibility to recurrent miscarriage (TG vs. TT: adjusted OR = 0.603; 95% CI = 0.420-0.866; p = 0.0062; GG/TG vs. TT: adjusted OR = 0.620; 95% CI = 0.441-0.873; p = 0.0061). The combined analysis of the two protective polymorphisms (rs3843549 AA and rs6983267 TG/GG) revealed that individuals with two unfavorable alleles exhibited a lower risk of recurrent miscarriage than those with no or only one unfavorable allele (adjusted OR = 0.531; 95% CI = 0.382-0.739). Moreover, the decreased risk associated with the two protective alleles was most obvious in women aged less than 35 years (OR = 0.551; 95% CI = 0.378-0.8803; p = 0.0019) and in women with two to three miscarriages (adjusted OR = 0.466; 95% CI = 0.318-0.683; p < 0.0001). In conclusion, our study indicates that the rs6983267G allele might contribute to a decreased risk of recurrent miscarriage in the South Chinese population.

Interleukin-3 Polymorphism is Associated with Miscarriage of Fresh in Vitro Fertilization Cycles

The aim of this study was to examine the association between interleukin (IL) genes polymorphisms and in vitro fertilization (IVF) outcome. A prospective cohort analysis was performed at a Women’s Hospital IVF centre of 1015 female patients undergoing fresh non-donor IVF cycles. The effects of the following six single nucleotide polymorphisms (SNPs) in five IL genes on IVF outcomes were explored: IL-1α (rs1800587 C/T), IL-3 (rs40401 C/T), IL-6 (rs1800795 C/G), IL-15 (rs3806798 A/T), IL-18 (rs187238 C/G) and IL-18 (rs1946518 G/T). The main outcome measures included clinical pregnancy, embryo implantation, abortion and live birth rates. There were no statistically significant differences in clinical pregnancy, embryo implantation and live birth rates in the analysis of 1015 patients attempting their first cycle of IVF. Infertile women with IL-3 homozygous major genotype had a higher abortion rate than those with heterozygous and homozygous minor genotype (16.5% vs. 7.9%, P = 0.025). In conclusion, our results indicated that the IL-3 rs40401 polymorphism is associated with increased risk of abortion of IVF patients. Future studies with inclusion of other ethnic populations must be conducted to confirm the findings of this study.

Interleukin-18 in Health and Disease

Interleukin (IL)-18 was originally discovered as a factor that enhanced IFN-γ production from anti-CD3-stimulated Th1 cells, especially in the presence of IL-12. Upon stimulation with Ag plus IL-12, naïve T cells develop into IL-18 receptor (IL-18R) expressing Th1 cells, which increase IFN-γ production in response to IL-18 stimulation. Therefore, IL-12 is a commitment factor that induces the development of Th1 cells. In contrast, IL-18 is a proinflammatory cytokine that facilitates type 1 responses. However, IL-18 without IL-12 but with IL-2, stimulates NK cells, CD4⁺ NKT cells, and established Th1 cells, to produce IL-3, IL-9, and IL-13. Furthermore, together with IL-3, IL-18 stimulates mast cells and basophils to produce IL-4, IL-13, and chemical mediators such as histamine. Therefore, IL-18 is a cytokine that stimulates various cell types and has pleiotropic functions. IL-18 is a member of the IL-1 family of cytokines. IL-18 demonstrates a unique function by binding to a specific receptor expressed on various types of cells. In this review article, we will focus on the unique features of IL-18 in health and disease in experimental animals and humans.

Investigating Association of rs5918 Human Platelets Antigen 1 and rs1800790 Fibrinogen β Chain as Critical Players with Recurrent Pregnancy Loss

Thrombophilia gene variants have been shown to be associated with higher risk of recurrent pregnancy loss (RPL). Due to the role of human platelets antigen 1 (HPA-1) and fibrinogen β chain (FGB) as critical players in the coagulation process, their most important variants including rs5918 T > C and rs1800790 G > A were selected to be studied in women affected by RPL. Three milliliters of peripheral blood were drawn from 110 women with history of at least two consecutive spontaneous abortion and 110 healthy women controls. rs5918 T > C and rs1800790 G > A of HPA-1 and FGB genes, respectively, were selected to be analyzed through polymerase chain reaction-restriction fragment length polymorphism (PCR_RFLP) following DNA isolation using QIAamp DNA Blood Mini Kit. Heterozygote genotype (TC) of HPA-1 gene rs5918 polymorphism was significantly associated with risk of RPL (p-value = 0.02). Although, rs1800790 G > A of FGB gene was not associated with RPL, its combination with rs5918 polymorphism was associated with increased risk of RPL. Owing to the critical roles of FGB and HPA-1 genes in coagulation, and thrombosis and several confinements on the meaningful association between the combination of those polymorphism with risk of RPL, including them in the thrombophilia panel may increase detection rate of hereditary thrombophilia patients. However, further studies with larger sample sizes are required to shed light on the exact role of the studied gene polymorphism, especially rs1800790 G > A of FGB gene variant in pathogenesis of RPL.

The Role of Interleukin-10 in the Pathophysiology of Preeclampsia

PURPOSE OF REVIEW

The pathophysiology of preeclampsia is complex and not entirely understood. A key feature in preeclampsia development is an immunological imbalance that shifts the maternal immune response from one of tolerance towards one promoting chronic inflammation and endothelial dysfunction. As a key regulator of immunity, IL-10 not only has immunomodulatory activity, but also directly benefits vasculature and promotes successful cellular interactions at the maternal-fetal interface. Here we focus on the mechanisms by which the dysregulation of IL-10 may contribute to the pathophysiology of preeclampsia.

RECENT FINDINGS

Dysregulation of IL-10 has been demonstrated in various animal models of preeclampsia. Decreased IL-10 production in both placenta and peripheral blood mononuclear cells has been reported in human studies, but with inconsistent results. The significance of IL-10 in preeclampsia has shifted from a key biomarker to one with therapeutic potential. As such, a better understanding of the role of this cytokine in the pathophysiology of preeclampsia is of paramount importance.

Recurrent pregnancy loss: current perspectives

Recurrent pregnancy loss is an important reproductive health issue, affecting 2%–5% of couples. Common established causes include uterine anomalies, antiphospholipid syndrome, hormonal and metabolic disorders, and cytogenetic abnormalities. Other etiologies have been proposed but are still considered controversial, such as chronic endometritis, inherited thrombophilias, luteal phase deficiency, and high sperm DNA fragmentation levels. Over the years, evidence-based treatments such as surgical correction of uterine anomalies or aspirin and heparin for antiphospholipid syndrome have improved the outcomes for couples with recurrent pregnancy loss. However, almost half of the cases remain unexplained and are empirically treated using progesterone supplementation, anticoagulation, and/or immunomodulatory treatments. Regardless of the cause, the long-term prognosis of couples with recurrent pregnancy loss is good, and most eventually achieve a healthy live birth. However, multiple pregnancy losses can have a significant psychological toll on affected couples, and many efforts are being made to improve treatments and decrease the time needed to achieve a successful pregnancy. This article reviews the established and controversial etiologies, and the recommended therapeutic strategies, with a special focus on unexplained recurrent pregnancy losses and the empiric treatments used nowadays. It also discusses the current role of preimplantation genetic testing in the management of recurrent pregnancy loss.