Interdisciplinary exchange of ideas: progestagens for autoimmunity, biologics for pregnancy complications

Assessing the causal relationship between immune traits and systemic lupus erythematosus by bi-directional Mendelian randomization analysis

Previous studies have observed relationships between immune cells and systemic lupus erythematosus (SLE), but their causal links remain undetermined. Based on the public available genome-wide association studies (GWAS) summary statistics, we conducted two-sample Mendelian randomization (MR) to evaluate the associations between 731 immune phenotypes and SLE pairs. Pairwise pleiotropy analysis was performed to identify pleiotropic genes for significant immunophenotype-SLE pairs. A comprehensive gene function analysis was undertaken to explore the mechanisms of immune cells in SLE. By using the instrumental variables extracted from GWAS data, we observed that increased levels of five immune phenotypes were causally associated with SLE risk (FDR < 0.05), that were CD20 on IgD+ CD38- naïve, BAFF-R on IgD+ CD38dim, CD39+ secreting Treg AC, CD14- CD16+ monocyte AC, and HLA DR on CD14+ monocyte. Pairwise gene-based analyses identified a total of 38 pleiotropic genes for 5 significant pairs identified and gene set enrichment analysis revealed the involvement of the identified pleiotropic genes in complex pathways (i.e., systemic lupus erythematosus, an integral component of luminal side of endoplasmic reticulum membrane, C-type lectin receptor signaling pathway and regulation of hormone secretion). This study demonstrates that the immune response influences the progression of SLE in a complex pattern. These findings greatly improve our understanding of the interaction between immune response and SLE risk and also aid in the design of therapeutic strategies from an immunological perspective.

Endocrine Autoimmunity in Pregnancy

Human gestation leads to a number of physiological alterations which peak at the development of placentta known for, among many other functions, being a transient but highly potent endocrine organ. Hormonal activity of placenta is marked by its ability to continuously produce and secrete high levels of progesterone. Progesterone guards the well-being of the fetoplacental unit throughout the gestation and one of the proposed mechanisms of this principle involves the development of local and systemic immune tolerance mainly due to impediment of CD4+ lymphocyte activation. However, though these alterations are present and well-established, autoimmunity is not entirely rare and a wide spectrum of diseases can continue, or develop de novo, throughout the gestation or even after the delivery. Up-to-date data supports the existence of a relationship between the clinical course of chosen autoimmune diseases and levels of circulating sex steroids.

The most common autoimmune endocrinopathies in pregnant women are Hashimoto’s disease, Graves’ disease, and, more rarely, primary adrenal insufficiency in the form of Addison’s disease. Gestation can influence the clinical course of these endocrinopathies in patients who were diagnosed before conception. Multiple particles, like TSH-receptor stimulating antibodies, thyroid hormones, glucocorticoids, and anti-thyroid medications, can cross the placental barrier and evoke biological action in fetal tissues. Thyroid pathology in the form of postpartum thyroiditis is particularly prevalent in patients with positive anti-thyroperoxidase and anti-thyroglobulin antibodies. Certain populations are more at risk of developing numerous gestational complications and require regular follow-up. In our paper, we would like to address physiological, physiopathological, and clinical aspects of endocrine autoimmunity throughout human gestation, as well as special circumstances to consider in pregnant women.

Updated advances of linking psychosocial factors and sex hormones with systemic lupus erythematosus susceptibility and development

Systemic lupus erythematosus (SLE) is a systemic autoimmune disease that primarily affects women, especially those of reproductive age. Genetics, environment, and gene-environment interactions play key roles in the development of SLE. Despite the numerous susceptibility genes of SLE identified to date, gene therapy is far from a clinical reality. Thus, more attention should be paid to the risk factors and underlying mechanisms of SLE. Currently, it is reported that psychosocial factors and sex hormones play vital roles in patients with SLE, which still need further investigated. The purpose of this review is to update the roles and mechanisms of psychosocial factors and sex hormones in the susceptibility and development of SLE. Based on review articles and reports in reputable peer-reviewed journals and government websites, this paper summarized psychosocial factors (e.g., alexithymia, depression, anxiety, negative emotions, and perceived stress) and sex hormones (e.g., estrogens, progesterone, androgens, and prolactin) involved in SLE. We further explore the mechanisms linking these factors with SLE susceptibility and development, which can guide the establishment of practical measures to benefit SLE patients and offer new ideas for therapeutic strategies.

Human leukocyte antigen DQ2/DQ8 positivity in women with history of stillbirth

PROBLEM

The aim of this study was to investigate the prevalence of human leukocyte antigens (HLA) DQ2 and DQ8 haplotypes, two common polymorphisms associate with celiac disease (CD), in women with previous stillbirth, but not affected by CD.

METHOD OF STUDY

Women with history of unexplained term stillbirth referred to our Center for High-Risk Pregnancies for a preconception counseling, and women with previous uncomplicated pregnancies, were enrolled as cases and controls. Celiac women were excluded from the study. Genetic tests for HLA DQ2/DQ8 were performed, and patients' data were compared.

RESULTS

The population included 56 women with a previous term stillbirth and 379 women with history of uncomplicated pregnancies. The prevalence of HLA-DQ2 or DQ8 positivity was significantly higher in cases than in controls (50% vs 29.5%) (P = 0.0031). Women with HLA DQ8 genotype have a significantly higher risk of stillbirth (OR: 2.84 CI: 1.1840-6.817) and in case of DQ2 genotype the OR for stillbirth was even higher (OR: 4.46 CI: 2.408-8.270). In the stillbirth group, SGA neonates were significantly more frequent in those with HLA-DQ2/DQ8 haplotypes than in those resulted negative to genetic testing (85.7% vs 42 .8%, P = 0.004).

CONCLUSION

In women with history of term stillbirth, a significantly higher prevalence of HLA DQ2/DQ8 haplotypes has been found compared to women with previous uneventful pregnancies. In addition, HLA DQ2/DQ8 positivity was significantly associated with suboptimal fetal growth in intrauterine fetal death cases, as shown by an increased prevalence of SGA babies.

The T helper type 17/regulatory T cell paradigm in pregnancy

T helper type 17 (Th17) and regulatory T (Treg) cells are active players in the establishment of tolerance and defence. These attributes of the immune system enmesh to guarantee the right level of protection. The healthy immune system, on the one hand, recognizes and eliminates dangerous non-self pathogens and, on the other hand, protects the healthy self. However, there are circumstances where this fine balance is disrupted. In fact, in situations such as in pregnancy, the foreign fetal antigens challenge the maternal immune system and Treg cells will dominate Th17 cells to guarantee fetal survival. In other situations such as autoimmunity, where the Th17 responses are often overwhelming, the immune system shifts towards an inflammatory profile and attacks the healthy tissue from the self. Interestingly, autoimmune patients have meliorating symptoms during pregnancy. This connects with the antagonist role of Th17 and Treg cells, and their specific profiles during these two immune challenging situations. In this review, we put into perspective the Th17/Treg ratio during pregnancy and autoimmunity, as well as in pregnant women with autoimmune conditions. We further review existing systems biology approaches that study specific mechanisms of these immune cells using mathematical modelling and we point out possible future directions of investigation. Understanding what maintains or disrupts the balance between these two opponent yet reciprocal cells in healthy physiological settings, sheds light into the development of innovative pharmacological approaches to fight pregnancy loss and autoimmunity.

Association between p53 polymorphism at codon 72 and recurrent spontaneous abortion

p53 gene plays an important role in apoptosis, which is necessary for successful invasion of trophoblast cells. The change from an arginine (Arg) to a proline (Pro) at codon 72 can influence the biological activity of p53, which predisposes to an increased risk of recurrent spontaneous abortion (RSA). In order to investigate the association between p53 polymorphism at codon 72 and RSA, we conducted this meta-analysis. Pubmed, Embase and Web of science were used to identify the eligible studies. Odds ratio (OR) with 95% confidence interval (CI) was used to evaluate the strength of the association. Six studies containing 937 cases of RSA and 830 controls were included, and there was one study deviated from Hardy-Weinberg equilibrium (HWE). There was a significant association between p53 polymorphism at codon 72 and RSA in recessive model (Pro/Pro vs. Pro/Arg+Arg/Arg; OR=1.60, 95% CI: 1.14-2.24) and co-dominant model (Pro/Pro vs. Arg/Arg; OR=1.47, 95% CI: 1.02-2.12) whether the study that was deviated from HWE was eliminated or not. A significant association was observed in allelic model (Pro vs. Arg; OR=1.28, 95% CI: 1.04-1.57) after exclusion of the study that was deviated from HWE. No association was noted in recessive model (Pro/Pro+Pro/Arg vs. Arg/Arg; OR=1.05, 95% CI: 0.86-1.30) and co-dominant model (Pro/Arg vs. Arg/Arg; OR=0.96, 95% CI: 0.77-1.19). Subgroup analysis by ethnicity also indicated a significant association between p53 polymorphism at codon 72 and RSA in Caucasian group. No heterogeneity and publication bias were found. Our meta-analysis implied that p53 polymorphism at codon 72 carries high maternal risk of RSA.

Pregnancy Associated with Systemic Lupus Erythematosus: Immune Tolerance in Pregnancy and Its Deficiency in Systemic Lupus Erythematosus--An Immunological Dilemma

Pregnancy is a physiological condition that requires immune tolerance to the product of conception. Systemic lupus erythematosus (SLE) is a disease with well-represented immune mechanisms that disturb immune tolerance. The association of pregnancy with systemic lupus erythematosus creates a particular immune environment in which the immune tolerance specific of pregnancy is required to coexist with alterations of the immune system caused by SLE. The main role is played by T regulatory (Treg) cells, which attempt to regulate and adapt the immune system of the mother to the new conditions of pregnancy. Other components of the immune system also participate to maintain maternal-fetal immune tolerance. If the immune system of pregnant women with SLE is not able to maintain maternal immune tolerance to the fetus, pregnancy complications (miscarriage, fetal hypotrophy, and preterm birth) or maternal complications (preeclampsia or activation of SLE, especially in conditions of lupus nephritis) may occur. In certain situations this can be responsible for neonatal lupus. At the same time, it must be noted that during pregnancy, the immune system is able to achieve immune tolerance while maintaining the anti-infectious immune capacity of the mother. Immunological monitoring of pregnancy during SLE, as well as of the mother's disease, is required. It is important to understand immune tolerance to grafts in transplant pathology.