Immunological adaptations in pregnancy that modulate rheumatoid arthritis disease activity

Updating on pregnancy in rheumatoid arthritis

INTRODUCTION

Rheumatoid arthritis (RA), the most prevalent autoimmune disease in reproductive years, exhibits a higher incidence in females, suggesting involvement of estrogens, genetics and environmental factors in disease onset. Literature shows smaller families in RA patients, driving increased interest in Assisted Reproductive Techniques.

AREAS COVERED

This review elucidates how immunotolerance mechanisms contribute to favorable pregnancy outcomes in RA, emphasizing the need for a careful pregnancy planning to mitigate fetal complications and postnatal flares, which surpass those in the general population. A thorough medication evaluation, orchestrated by a multidisciplinary team, is imperative during pregnancy, weighing potential teratogenic effects against safer alternatives to balance medication safety with disease control. A systematic literature search on PubMed and MEDLINE, using specific terms, covered relevant academic journals up to the latest date.

EXPERT OPINION

This narrative review comprehensively addresses pregnancy-related considerations in RA patients, prioritizing meticulous disease management with pregnancy and breastfeeding-compatible drugs in line with the latest recommendations and registry data. The focus remains on evaluating glucocorticoids, conventional, and biological disease-modifying drugs for compatibility during pregnancy and breastfeeding. Additionally, the evolving landscape of targeted synthetic drugs during pregnancy is explored, providing insights into the latest developments in rheumatological care.

Cell-type specific molecular expression levels by restricted-dimensional cytometry

BACKGROUND

Cytometric analysis has been commonly used to delineate distinct cell subpopulations among peripheral blood mononuclear cells by the differential expression of surface receptors. This capability has reached its apogee with high-dimensional approaches such as mass cytometry and spectral cytometry that include simultaneous assessment of 20-50 analytes. Unfortunately, this approach also engenders significant complexity with analytical and interpretational pitfalls.

METHODS

Here, we demonstrate a complementary approach with restricted-dimensionality to assess cell-type specific intracellular molecular expression levels at exceptional levels of precision. The expression of five analytes was individually assessed in four mononuclear cell-types from peripheral blood.

RESULTS

Distinctions in expression levels were seen between cell-types and between samples from different donor groups. Mononuclear cell-type specific molecular expression levels distinguished pregnant from nonpregnant women and G-CSF-treated from untreated persons. Additionally, the precision of our analysis was sufficient to quantify a novel relationship between two molecules-Rel A and translocator protein-by correlational analysis.

CONCLUSIONS

Restricted-dimensional cytometry can provide a complementary approach to define characteristics of cell-type specific intracellular protein and phosphoantigen expression in mononuclear cells.

Impact of previous pregnancy and BMI on cellular and serum immune activity from early to late pregnancy

Immunological adaptions during pregnancy play a crucial role in healthy fetal development. Aberrant immune modifications however contribute to adverse pregnancy outcomes, which may be driven by maternal factors such as previous pregnancies and BMI. This secondary analysis of the MicrobeMom2 RCT investigates the changes to maternal inflammatory biomarkers derived from serum and stimulated peripheral blood mononuclear cells (PBMCs) during pregnancy, and the effects of previous pregnancies (parity) and BMI on maternal immune responses. Changes in immune and metabolic biomarkers from early (11-15 weeks' gestation) to late (28-32 weeks' gestation) pregnancy were compared using paired t-tests. Participants were then split by parity (nulliparous, parous) and BMI (BMI < 25, BMI > = 25), and the relationship between parity and BMI with immune biomarker levels was examined using independent t-tests, paired t-tests, ANCOVA, and linear regression. Equivalent non-parametric tests were used for skewed data. Recruited women (n = 72) were on average 31.17 (SD ± 4.53) years of age and 25.11 (SD ± 3.82) BMI (kg/m2). Of these, 51 (70.8%) had a previous term pregnancy. Throughout gestation, PBMC cytokines displayed contrasting trends to serum, with a dampening of immune responses noted in PBMCs, and enhanced production of cytokines observed in the serum. Significant decreases in PBMC derived TNF-α, IL-10 and IFN-γ were seen from early to late pregnancy. Serum C3, IL-17A, IL-6, TNF-α, CD163, GDF-15 and leptin increased throughout gestation. First pregnancy was associated with higher levels of leptin in late pregnancy, while parous women showed significant decreases in PBMC derived TNF-α, IL10, and IFN-γ with gestation. Differences in levels of C3, IL-17A, TNF-α, GDF-15 and leptin were observed across BMI groups. Overall, serum-derived cytokines exhibit contrasting levels to those derived from stimulated PBMCs. Maternal immune responses undergo significant changes from early to late pregnancy, which are influenced by parity and BMI. These differences aid our understanding as to why first-time mothers are at greater risk of placental disease such as pre-eclampsia and fetal growth restriction.

Risk Assessment and Optimization for Pregnancy in Patients with Rheumatic Diseases

Patients with rheumatic diseases frequently operate with incomplete or incorrect information while planning for and experiencing pregnancy, often due to variability in provider care and knowledge. Risk assessment at each stage of pregnancy-pre-conception, during pregnancy, and postpartum-is focused on reducing maternal and neonatal complications. This review aims to compile updated, evidence-based guidance on how to minimize risk factors contributing to adverse pregnancy outcomes (APOs). Mitigation of known causes of infertility, appropriate testing and monitoring, achieving low disease activity on pregnancy-safe disease-modifying antirheumatic drugs (DMARDs) prior to conception, controlling hypertension (a frequent comorbidity among patients with certain rheumatic diseases), and the use of appropriate adjunctive medications (such as low-dose aspirin when preeclampsia risk is high) can optimize fertility and prevent adverse maternal and neonatal outcomes.

An Early Gestation Plasma Inflammasome in Rural Bangladeshi Women

Circulating α1-acid glycoprotein (AGP) and C-reactive protein (CRP) are commonly measured to assess inflammation, but these biomarkers fail to reveal the complex molecular biology of inflammation. We mined the maternal plasma proteome to detect proteins that covary with AGP and CRP. In 435 gravida predominantly in <12-week gestation, we correlated the relative quantification of plasma proteins assessed via a multiplexed aptamer assay (SOMAScan®) with AGP and CRP, quantified by immunoassay. We defined a plasma inflammasome as protein correlates meeting a false discovery rate <0.05. We examined potential pathways using principal component analysis. A total of 147 and 879 of 6431 detected plasma proteins correlated with AGP and CRP, respectively, of which 61 overlapped with both biomarkers. Positive correlates included serum amyloid, complement, interferon-induced, and immunoregulatory proteins. Negative correlates were micronutrient and lipid transporters and pregnancy-related anabolic proteins. The principal components (PCs) of AGP were dominated by negatively correlated anabolic proteins associated with gestational homeostasis, angiogenesis, and neurogenesis. The PCs of CRP were more diverse in function, reflecting cell surface and adhesion, embryogenic, and intracellular and extra-hepatic tissue leakage proteins. The plasma proteome of AGP or CRP reveals wide proteomic variation associated with early gestational inflammation, suggesting mechanisms and pathways that merit future research.

Immune cells at the feto-maternal interface: Comprehensive characterization and insights into term labor

Immune cells at the feto-maternal interface play an important role in pregnancy; starting at implantation, maintenance of pregnancy, and parturition. The role of decidual immune cells in induction of labor still needs to be understood. Published reports on this topic show heterogeneity in methods of cell isolation, assay, analysis and cellular characterization making it difficult to collate available information in order to understand the contribution of immune cells at term leading to parturition. In the present study, available literature was reviewed to study the differences in immune cells between the decidua basalis and decidua parietalis, as well as between immune cells in term and preterm labor. Additionally, immune cells at the decidua parietalis were isolated from term not in labor (TNL) or term in labor (TL) samples and characterized via flow cytometry using a comprehensive, high-dimensional antibody panel. This allowed a full view of immune cell differences without combining multiple studies, which must include variation in isolation and analysis methods, for more conclusive data. The ratio of cells found in decidua parietalis in this study generally matched those reported in the literature, although we report a lower percentage of natural killer (NK) cells at term. We report that CD4 expression on CD8- NK cells decreased in term labor compared to not in labor samples, suggesting that natural killer cells may be migrating to other sites during labor. Also, we report a decrease in CD38 expression on CD8+ CD57+ T cells in labor, indicative of cytotoxic T cell senescence. Our study provides a comprehensive status of immune cells at the decidua-chorion interface at term.

Pregnancy and the Autoimmune Patient

PURPOSE OF REVIEW

This article will review the current understanding of the immunologic changes that occur during pregnancy. It will discuss the impact of pregnancy on the disease activity of autoimmune or inflammatory rheumatic diseases (AIRD). Lastly, it will highlight the most recent data on pre-conception and pregnancy management practices that can improve pregnancy outcomes in autoimmune patients.

RECENT FINDINGS

Pregnancy is an immunologically complex and dynamic state that may affect the activity of AIRDs, with more patients having active disease during pregnancy than previously thought. Uncontrolled inflammatory diseases are associated with poor pregnancy outcomes such as preeclampsia, small for gestational age infants, and prematurity. Pre-conception counseling and early pregnancy planning discussions can help ensure optimal disease control and medication management prior to attempting conception. Adequate control of AIRDs on pregnancy-compatible medications during the pre-conception, pregnancy, and postpartum periods is required for optimal pregnancy outcomes.

Intestinal flora and pregnancy complications: Current insights and future prospects

Numerous studies have demonstrated the pivotal roles of intestinal microbiota in many physiopathological processes through complex interactions with the host. As a unique period in a woman's lifespan, pregnancy is characterized by changes in hormones, immunity, and metabolism. The gut microbiota also changes during this period and plays a crucial role in maintaining a healthy pregnancy. Consequently, anomalies in the composition and function of the gut microbiota, namely, gut microbiota dysbiosis, can predispose individuals to various pregnancy complications, posing substantial risks to both maternal and neonatal health. However, there are still many controversies in this field, such as "sterile womb" versus "in utero colonization." Therefore, a thorough understanding of the roles and mechanisms of gut microbiota in pregnancy and its complications is essential to safeguard the health of both mother and child. This review provides a comprehensive overview of the changes in gut microbiota during pregnancy, its abnormalities in common pregnancy complications, and potential etiological implications. It also explores the potential of gut microbiota in diagnosing and treating pregnancy complications and examines the possibility of gut-derived bacteria residing in the uterus/placenta. Our aim is to expand knowledge in maternal and infant health from the gut microbiota perspective, aiding in developing new preventive and therapeutic strategies for pregnancy complications based on intestinal microecology.

Medication utilisation trends during pregnancy and factors influencing adverse pregnancy outcomes in patients with rheumatoid arthritis

OBJECTIVES

We aimed to investigate medication utilisation trends during pregnancy and identify factors associated with adverse pregnancy outcomes (APOs) in patients with rheumatoid arthritis (RA).

METHODS

Female patients with RA aged 20-50 years were identified from the Korean national health insurance database between 2010 and 2020. Pregnancy episodes were divided into two groups according to pregnancy outcome: the delivery group and the APO group (abortion and stillbirth). The characteristics and medication utilisation patterns were compared between the two groups, and multivariable logistic regression analysis was conducted to identify the factors associated with APOs.

RESULTS

A total of 5728 pregnancy episodes were included, comprising 4576 delivery episodes and 1152 APO episodes. The mean maternal age for all pregnancy episodes was 33.7 years; 33.3 years in the delivery group and 33.7 years in the APO group. Hydroxychloroquine was the most commonly used conventional synthetic disease-modifying antirheumatic drug (DMARD) during the preconception period and pregnancy in both groups. The prescription rate of all DMARDs decreased rapidly during pregnancy. In the multivariable analysis, use of methotrexate (adjusted OR (aOR): 2.14, 95% CI 1.57 to 2.92) and leflunomide (aOR: 2.68, 95% CI 1.39 to 5.15) within 3 months before conception was associated with APOs.

CONCLUSION

Methotrexate and leflunomide are associated with an increased possibility of APOs, emphasising the importance of appropriate medication adjustment when planning for pregnancy.

Uterine macrophages and NK cells exhibit population and gene-level changes after implantation but maintain pro-invasive properties

Introduction

Prior to pregnancy, hormonal changes lead to cellular adaptations in the endometrium allowing for embryo implantation. Critical for successful pregnancy establishment, innate immune cells constitute a significant proportion of uterine cells prior to arrival of the embryo and throughout the first trimester in humans and animal models. Abnormal uterine immune cell function during implantation is believed to play a role in multiple adverse pregnancy outcomes. Current work in humans has focused on uterine immune cells present after pregnancy establishment, and limited in vitro models exist to explore unique functions of these cells.

Methods

With single-cell RNA-sequencing (scRNAseq), we comprehensively compared the human uterine immune landscape of the endometrium during the window of implantation and the decidua during the first trimester of pregnancy.

Results

We uncovered global and cell-type-specific gene signatures for each timepoint. Immune cells in the endometrium prior to implantation expressed genes associated with immune metabolism, division, and activation. In contrast, we observed widespread interferon signaling during the first trimester of pregnancy. We also provide evidence of specific inflammatory pathways enriched in pre- and post-implantation macrophages and natural killer (NK) cells in the uterine lining. Using our novel implantation-on-a-chip (IOC) to model human implantation ex vivo, we demonstrate for the first time that uterine macrophages strongly promote invasion of extravillous trophoblasts (EVTs), a process essential for pregnancy establishment. Pre- and post-implantation uterine macrophages promoted EVT invasion to a similar degree as pre- and post-implantation NK cells on the IOC.

Conclusions

This work provides a foundation for further investigation of the individual roles of uterine immune cell subtypes present prior to embryo implantation and during early pregnancy, which will be critical for our understanding of pregnancy complications associated with abnormal trophoblast invasion and placentation.

Bidirectional association between autoimmune disease and perinatal depression: a nationwide study with sibling comparison

Although major depression, characterized by a pro-inflammatory profile, genetically overlap with autoimmune disease (AD) and the perinatal period involve immune system adaptations and AD symptom alterations, the bidirectional link between perinatal depression (PND) and AD is largely unexplored. Hence, the objective of this study was to investigate the bidirectional association between PND and AD. Using nationwide Swedish population and health registers, we conducted a nested case-control study and a matched cohort study. From 1,347,901 pregnancies during 2001-2013, we included 55,299 incident PND, their unaffected full sisters, and 10 unaffected matched women per PND case. We identified 41 subtypes of AD diagnoses recorded in the registers and compared PND with unaffected population-matched women and full sisters, using multivariable regressions. Women with an AD had a 30% higher risk of subsequent PND (95% CI 1.2-1.5) and women exposed to PND had a 30% higher risk of a subsequent AD (95% CI 1.3-1.4). Comparable associations were found when comparing exposed women with their unaffected sisters (nested case-control OR: 1.3, 95% CI 1.2-1.5, matched cohort HR: 1.3, 95% CI 1.1-1.6), and when studying antepartum and postpartum depression. The bidirectional association was more pronounced among women without psychiatric comorbidities (nested case-control OR: 1.5, 95% CI 1.4-1.6, matched cohort HR: 1.4, 95% CI 1.4-1.5) and strongest for multiple sclerosis (nested case-control OR: 2.0, 95% CI 1.6-2.3, matched cohort HR: 1.8, 95% CI 1.0-3.1). These findings demonstrate a bidirectional association between AD and PND independent of psychiatric comorbidities, suggesting possibly shared biological mechanisms. If future translational science confirms the underlying mechanisms, healthcare providers need to be aware of the increased risk of PND among women with ADs and vice versa.

Gene expression in multiple sclerosis during pregnancy based on integrated bioinformatics analysis

BACKGROUND

The modulation of the activity disease in patients with Multiple Sclerosis (MS) that occurs during pregnancy is a helpful model which could provide insight into central disease mechanisms and facilitate treatment. Therefore, the aim of the study was to identify differentially expressed genes in-silico to perform biological function pathway enrichment analysis and protein-protein interaction from pregnant women with MS.

METHODS

Transcriptome data were obtained from the Gene Expression Omnibus (GEO) database. We selected the microarray dataset GSE17449. The gene expression dataset contains the data of mononuclear cells from four different groups sought, including seven healthy women (H), four healthy pregnant women (HP), eight women with multiple sclerosis (WMS), and nine women nine months pregnant with multiple sclerosis (PMS). The GSEA software was employed for enrichment analysis, and the REACTOME database was used for biological pathways. The protein-protein interaction (PPI) network was plotted with STRING. The databases used to identify the connection of DEGs with different signaling pathways were KEGG and WIKIPATHWAYS.

RESULTS

We identified 42 differentially expressed genes in pregnant women with MS. The significant pathways included IL-10 signaling pathway, ErbB2 activates, the hemoglobin complex (HBD, HBB, HBA1, AHSP, and HBA2), IL-17 signaling pathway (LCN2 and MMP9), antigen processing and presentation, and Th17 cell differentiation (HLA-DQA1), Rap1 signaling pathway (ID1), NOD-Like receptor signaling pathway (CAMP and DEFA4), PD-L1 Signaling, Interferon gamma signaling (MMP9 and ARG1), Neutrophil degranulation (CAMP, DEFA4, ELANE, CEACAM8, S100P, CHI3L1, AZU1, OLFM4, CRISP3, LTF, ARG1, PGLYRP1, and TCN1). In the WIKIPATHWAYS set, significance was found Vitamin B12 metabolism (TCN1, HBB, and HBA2), and IL-18 signaling pathway (S100P).

CONCLUSION

This study can be used to understand several essential target genes and pathways identified in the present study, which may serve as feasible targets for MS therapies.

Maternal immunization in women living with HIV

Thanks to widespread use of antiretroviral therapy worldwide, women living with HIV (WLWH) are becoming pregnant and giving birth to HIV-exposed but uninfected (HEU) newborns. Both pregnancy and HIV infection-related factors such as low CD4+ T-cell count or uncontrolled viral load increase the risk of severe infections such as influenza, COVID-19, and others, making maternal immunization a valuable tool to decrease maternal morbidity among WLWH. Vaccines administered during pregnancy may also benefit the health of HEU infants. Indeed, HEU infants suffer from higher risk of morbidity of infectious origin, including respiratory syncytial virus (RSV), group B streptococcus (GBS), pneumococcus and pertussis infections. Maternal pertussis immunization is recommended in various high-income countries but not in many low-middle income countries where HIV prevalence is higher. GBS and RSV vaccines to be administered during pregnancy are currently in late-phase clinical trials in HIV-uninfected women and could represent a valuable tool to decrease morbidity during infancy. Decreased transfer of vaccine-specific IgG, accelerated waning of vaccine-induced antibody responses, linked to persistent maternal immune activation, and blunting of infant immune response to vaccines could hamper vaccine effectiveness among WLWH and HEU infants. Vaccine hesitancy could limit benefits of maternal immunization and strategies to tackle vaccine hesitancy should be part of HIV routine care. The aim of this review is to summarize the current knowledge regarding the immunogenicity and efficacy of available and upcoming vaccines recommended during pregnancy of WLWH.

Causal association between rheumatoid arthritis and pregnancy loss and intrauterine growth retardation: A bidirectional two-sample Mendelian randomization study

OBJECTIVE

To investigate the causal relationship between rheumatoid arthritis (RA) and pregnancy loss and intrauterine growth retardation (IUGR) using Mendelian randomization (MR).

METHODS

Genetic variants associated with RA (12,555 cases and 240,862 controls), miscarriage (1475 cases and 149,622 controls), and IUGR (3558 cases and 207,312 controls) were obtained from the FinnGen consortium, and supplementary data on RA (5201 cases and 457,732 controls) and miscarriage (7069 cases and 250,492 controls) were obtained from the Medical Research Council Integrated Epidemiology Unit (MRC-IEU). 47 Single nucleotide polymorphisms (SNPs) associated with RA were screened as instrumental variables (IV). The causal relationship between RA and pregnancy loss and IUGR were assessed by 5 MR methods, mainly inverse variance weighting (IVW). Sensitivity analyses were also performed to test the stability of the results.

RESULTS

Bidirectional MR showed that genetically predicted RA was causally associated with pregnancy loss and IUGR in forward MR analyses, and that RA significantly increased pregnancy loss [odds ratio (OR) = 1.13, 95% confidence interval (CI): 1.00-1.33, P = .03] and IUGR (OR = 1.08, 95% CI: 1.01-1.15, P = .019). In the reverse MR, there was no causal association between pregnancy loss (P = .15) and IUGR (P = .87) and RA.

CONCLUSION

This study found a significant genetic association between RA and pregnancy loss and IUGR. RA is considered to be a high-risk factor for adverse maternal outcomes. Pre-pregnancy prophylaxis and intra-pregnancy control of patients should be emphasized to reduce the incidence of adverse pregnancy outcomes such as pregnancy loss and IUGR.

Circulating levels of inflammatory mediators in pregnant people living with HIV according to antiretroviral therapy regimen

Introduction

The use of antiretroviral therapy (ART) during pregnancy, particularly protease-inhibitor-based regimens (PI), has been linked to adverse outcomes including preterm delivery. As this outcome may be related to systemic inflammation, we sought to characterize inflammatory profiles of pregnant people living with HIV (PLWH) by comparing their levels of inflammatory mediators at two timepoints during pregnancy according to ART regimen, and to HIV-negative controls.

Methods

Second and third trimester samples from 144 pregnant PLWH treated with ART and 24 HIV-uninfected controls were retrieved from the CARMA-PREG cohort. Peripheral plasma levels of 12 inflammatory mediators previously linked to HIV infection and/or poor pregnancy outcomes were quantified by multiplex assay: HMGB1, GM-CSF, IFNα, IFNβ, IFNγ, IL-10, IL-17, IL-1β, IL-6, TNFα, AGP, and CRP. Levels were compared by ART regimen and HIV status.

Results

Adjusted analyses showed that PLWH have higher levels of AGP throughout pregnancy and lower levels of IFNγ and IL-1β during the second trimester. PI-based regimens are associated with significantly higher levels of IFNα and IL-17 during the second trimester and IFNα, CRP, HMGB1, and IFNβ during the third trimester compared to InSTI-based regimens. The PI-subgroup was associated with preterm delivery and higher HIV-1 viral load.

Discussion

Our results suggest that PI-based regimens are associated with a pro-inflammatory and antiviral immunological response and a high viral load, which may be a mechanism through which PI-based regimens increase the risk of preterm delivery. Further investigations into cellular mechanisms and pro-inflammatory cascades leading to preterm delivery are necessary to support this association.

Immunomodulation of Antibody Glycosylation through the Placental Transfer

Establishing an immune balance between the mother and fetus during gestation is crucial, with the placenta acting as the epicenter of immune tolerance. The placental transfer of antibodies, mainly immunoglobulin G (IgG), is critical in protecting the developing fetus from infections. This review looks at how immunomodulation of antibody glycosylation occurs during placental transfer and how it affects fetal health. The passage of maternal IgG antibodies through the placental layers, including the syncytiotrophoblast, stroma, and fetal endothelium, is discussed. The effect of IgG subclass, glycosylation, concentration, maternal infections, and antigen specificity on antibody transfer efficiency is investigated. FcRn-mediated IgG transport, influenced by pH-dependent binding, is essential for placental transfer. Additionally, this review delves into the impact of glycosylation patterns on antibody functionality, considering both protective and pathological effects. Factors affecting the transfer of protective antibodies, such as maternal vaccination, are discussed along with reducing harmful antibodies. This in-depth examination of placental antibody transfer and glycosylation provides insights into improving neonatal immunity and mitigating the effects of maternal autoimmune and alloimmune conditions.

Uterine Nodal expression supports maternal immunotolerance and establishment of the FOXP3+ regulatory T cell population during the preimplantation period

Pregnancy success is dependent on the establishment of maternal tolerance during the preimplantation period. The immunosuppressive function of regulatory T cells is critical to limit inflammation arising from implantation of the semi-allogeneic blastocyst. Insufficient maternal immune adaptations to pregnancy have been frequently associated with cases of female infertility and recurrent implantation failure. The role of Nodal, a secreted morphogen of the TGFβ superfamily, was recently implicated during murine pregnancy as its conditional deletion (NodalΔ/Δ) in the female reproductive tract resulted in severe subfertility. Here, it was determined that despite normal preimplantation processes and healthy, viable embryos, NodalΔ/Δ females had a 50% implantation failure rate compared to NodalloxP/loxP controls. Prior to implantation, the expression of inflammatory cytokines MCP-1, G-CSF, IFN-γ and IL-10 was dysregulated in the NodalΔ/Δ uterus. Further analysis of the preimplantation leukocyte populations in NodalΔ/Δ uteri showed an overabundance of infiltrating, pro-inflammatory CD11bhigh Ly6C+ macrophages coupled with the absence of CD4+ FOXP3+ regulatory T cells. Therefore, it is proposed that uterine Nodal expression during the preimplantation period has a novel role in the establishment of maternal immunotolerance, and its dysregulation should be considered as a potential contributor to cases of female infertility and recurrent implantation failure.

Characterization of the immune environment in pregnancy-associated breast cancer

Pregnancy-associated breast cancer (PrBC) is a rare and clinically challenging condition. Specific immune mechanisms and pathways are involved in maternal-fetal tolerance and tumor-host immunoediting. The comprehension of the molecular processes underpinning this immune synergy in PrBC is needed to improve patients' clinical management. Only a few studies focused on the immune biology of PrBC and attempted to identify bona fide biomarkers. Therefore, clinically actionable information remains extremely puzzling for these patients. In this review article, we discuss the current knowledge on the immune environment of PrBC, in comparison with pregnancy-unrelated breast cancer and in the context of maternal immune changes during pregnancy. A particular emphasis is given to the actual role of potential immune-related biomarkers for PrBC clinical management.

Maternal microbiota and gestational diabetes: impact on infant health

Gestational diabetes mellitus (GDM) is a common complication of pregnancy that has been associated with an increased risk of obesity and diabetes in the offspring. Pregnancy is accompanied by tightly regulated changes in the endocrine, metabolic, immune, and microbial systems, and deviations from these changes can alter the mother's metabolism resulting in adverse pregnancy outcomes and a negative impact on the health of her infant. Maternal microbiomes are significant drivers of mother and child health outcomes, and many microbial metabolites are likely to influence the host health. This review discusses the current understanding of how the microbiota and microbial metabolites may contribute to the development of GDM and how GDM-associated changes in the maternal microbiome can affect infant's health. We also describe microbiota-based interventions that aim to improve metabolic health and outline future directions for precision medicine research in this emerging field.

Immunology of pregnancy and reproductive health in autoimmune rheumatic diseases. Update from the 11th International Conference on Reproduction, Pregnancy and Rheumatic Diseases

Autoimmune rheumatic diseases (ARD) can affect women and men during fertile age, therefore reproductive health is a priority issue in rheumatology. Many topics need to be considered during preconception counselling: fertility, the impact of disease-related factors on pregnancy outcomes, the influence of pregnancy on disease activity, the compatibility of medications with pregnancy and breastfeeding. Risk stratification and individualized treatment approach elaborated by a multidisciplinary team minimize the risk of adverse pregnancy outcomes (APO). Research has been focused on identifying biomarkers that can be predictive of APO. Specifically, preeclampsia and hypertensive disorders of pregnancy tend to develop more frequently in women with ARD. Placental insufficiency can lead to intrauterine growth restriction and small-for-gestational age newborns. Such APO have been shown to be associated with maternal disease activity in different ARD. Therefore, a key message to be addressed to the woman wishing for a pregnancy and to her family is that treatment with compatible drugs is the best way to ensure maternal and fetal wellbeing. An increasing number of medications have entered the management of ARD, but data about their use in pregnancy and lactation are scarce. More information is needed for most biologic drugs and their biosimilars, and for the so-called small molecules, while there is sufficient evidence to recommend the use of TNF inhibitors if needed for keeping maternal disease under control. Other issues related to the reproductive journey have emerged as "unmet needs", such as sexual dysfunction, contraception, medically assisted reproduction techniques, long-term outcome of children, and they will be addressed in this review paper. Collaborative research has been instrumental to reach current knowledge and the future will bring novel insights thanks to pregnancy registries and prospective studies that have been established in several Countries and to their joint efforts in merging data.

Rheumatoid arthritis and the risk of preterm birth

During pregnancy, many diseases are correlated with different adverse outcomes. In turn, pregnancy affects the body, leading to increased disease susceptibility. This interplay between diseased states and pregnancy outcomes is illustrated in the effect of the chronic autoimmune disorder, rheumatoid arthritis (RA), and the adverse outcome, preterm birth (PTB). RA is a systemic disorder characterized by inflammation of the joints and other body organs. Joint pain and swelling are the most prominent manifestations of RA during pregnancy. However, the exact role of RA on PTB among pregnant women has yet to be established. This review highlighted the immunologic mechanisms involved in PTB in pregnant patients with RA. The immune cell population in pregnant women with RA exhibited higher activity of macrophages, dendritic cells, neutrophils, helper T (Th) 1 cells, and Vδ1 cells, but lower activity of CD4 + CD25^high T regulatory (CD24 + CD25^high T_reg ), Th2, and Vδ2 cells. Increased pro-inflammatory cytokines IL-6, TNF-α, and IFN-γ and decreased anti-inflammatory cytokines IL-12 and IL-10 are also exhibited by pregnant patients with RA. This review also discussed factors that may predict the risk of PTB in RA. These include disease activity and severity of RA, laboratory parameters (cytokines and immune cell population), and sociodemographic factors such as ethnicity, smoking, alcohol intake, and the level of education. Current findings on the underlying immunological mechanisms of RA can help identify possible strategies to prevent PTB.

Pharmacokinetics of antibodies during Pregnancy: Impact of pregnancy on the pharmacokinetics of antibodies (Part 2)

In Part 1, we provided a general description of macromolecules, pharmacokinetics (PK) characteristics in non-pregnant subjects, and the physiological changes during pregnancy. Here we further elaborate on the impact of pregnancy on the PK of antibodies through illustrative case studies (immunoglobulins, infliximab, adalimumab and eculizumab). Using published data from nonclinical and clinical studies, we present measured or calculated PK parameters from pregnant subjects comparing with data from non-pregnant subjects, if available. Due to the paucity of PK data evaluating PK of antibodies during pregnancy, we also provide examples of PK studies for small molecules. Finally, we draw conclusions on the nature and direction of PK changes for both antibodies and small molecules as well as provide recommendations for areas that would benefit from further studies.

TNFα/TNFR1 signal induces excessive senescence of decidua stromal cells in recurrent pregnancy loss

Defects in decidual response are associated with adverse pregnancy outcomes which includes recurrent pregnancy loss (RPL). It is reported that cellular senescence happens during decidualization and pro-senescent decidual response in the luteal phase endometrium is related to RPL. However, the underlying mechanisms of how excessive decidual senescence takes place in RPL decidua cells remain largely unexplored. The senescent phenotype of RPL decidua and tumor necrosis factor receptor 1(TNFR1) expression were analyzed by using our previously published single-cell sequencing dataset of decidua cells from 6 RPL and 5 matched normal decidua, which were further verified by PCR and WB in decidual tissues. Effects of TNFα on the decidual stromal cells (DSCs) senescence and underlying molecular pathways were analyzed using the in vitro decidualization model of human endometrial stromal cells (HESCs). We showed that decidual stroma cells from RPL patients exhibited transcriptomic features of cellular senescence by analysis of single-cell datasets. The TNFα level and TNFR1 expression were increased in RPL decidua tissues. Furthermore, in vitro cell model demonstrated that increased TNFα induced excessive senescence during decidualization and TNFR1/p53/p16 pathway mediates TNFα-induced stromal senescence. In addition, we also found that the expression of IGFBP1 was regulated by TNFα-TNFR1 interaction during decidualization. Taken together, the present findings suggest that the increased secretion of TNFα induced stromal cell excessive senescence in RPL decidua, which is mediated via TNFR1, and thus provide a possible therapeutic target for the treatment of RPL.

Rheumatic Diseases in Reproductive Age-the Possibilities and the Risks

The most common systemic connective tissue diseases (CTD), such as rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), antiphospholipid syndrome (APS), systemic sclerosis (SSc), and Sjögren's syndrome (SjS), affect many women of reproductive age. These diseases may strongly impact the course of pregnancy and increase the risk factors of incompatibility. A literature search was done on MEDLINE, PubMed, and Google Scholar in 2011-2021. The analysis included meta-analysis, randomized control trials, prospective and retrospective studies, and systematic reviews. The literature search allowed us to form conclusions and underline recommendations regarding pregnancy's risk and treatment possibilities in the course of rheumatic disease. Optimal control of CTD activity should be reached at least 6 months before conception. High-risk pregnancies are often accompanied by maternal-placental syndrome, which manifests as preeclampsia, eclampsia, fetal growth restriction, and prematurity. The flare of rheumatic disease can coexist with obstetrical complications, and differential diagnosis can be difficult. Medications that do not influence the risk of fetus complications should be applied before and during pregnancy. Teratogenic drugs (e.g., methotrexate, leflunomide, cyclophosphamide) must be withdrawn before pregnancy. Conventional medications such as hydroxychloroquine, sulfasalazine, colchicine, and the TNFα inhibitor certolizumab can be used safely at any stage of pregnancy. Corticosteroids should be tapered, and other biologics should be avoided due to teratogenicity or carefully administered due to the impact on the fetal immune system. Distinguishing between disease flare and obstetrical complications can be difficult in clinical practice; however, some clinical symptoms and serological markers can be helpful in the differential diagnosis.

Immunology of Pregnancy and Systemic Consequences

Pregnancy is an immunological paradox, with renowned Nobel Prize winning transplantation biologist Sir Peter Brian Medawar being the first to introduce this concept back in 1953. This concept considers how the maternal immune system can tolerate the developing fetus, which is 50% antigenically foreign to the uterus. There have been significant advances in our understanding of the immune system in regulating fertility, pregnancy and in complications of these, and what was once considered a paradox can be seen as a highly evolved system. Indeed, the complexity of the maternal-fetal interface along with our ever-advancing knowledge of immune cells and mediators means that we have a better understanding of these interactions, with gaps still present.  This chapter will summarise the key aspects of the role of the immune system at each stage of pregnancy and highlight the recent advances in our knowledge.

Immunophenotyping of peripheral blood monocytes could help identify a baseline pro-inflammatory profile in women with recurrent reproductive failure

Recurrent pregnancy loss (RPL) and recurrent implantation failure (RIF) are two well-defined clinical entities, but the role of the monocytes in their pathophysiology needs to be clarified. This study aimed to evaluate the role of the three monocyte subsets (classical, intermediate, and non-classical) and relevant cytokines/chemokines in a cohort of RPL and RIF women to better characterize a baseline proinflammatory profile that could define inflammatory pathophysiology in these two different conditions. We evaluated 108 non-pregnant women: 53 RPL, 24 RIF, and 31 fertile healthy controls (HC). Multiparametric flow cytometry was used to quantify the frequency of surface chemokine receptors (CCR2, CCR5, and CX3CR1) on the monocyte subsets. Cytokines were assessed in plasma samples using a multiplex assay. The CX3CR1⁺ and CCR5⁺ intermediate monocytes were significantly higher in RPL and RIF compared to HC. A significant positive correlation was observed between CX3CR1⁺ intermediate monocytes and IL-17A (P = .03, r = 0.43). The Boruta algorithm followed by a multivariate logistic regression model was used to select the most relevant variables that could help define RPL and RIF: in RPL were CX3CR1 non-classical monocytes, TGF-β1, and CCR5 intermediate monocytes; in RIF: CCR5 intermediate monocytes and TGF-β3. The combination of these variables could predict RPL and RIF with 90 % and 82 %, respectively. Our study suggests that a combination of specific blood monocyte subsets and cytokines could aid in identifying RPL and RIF women with a pro-inflammatory profile. These findings could provide a more integrated understanding of these pathologies. Further investigation and validation in independent cohorts are warranted.

Local immune recognition of trophoblast in early human pregnancy: controversies and questions

The role of the maternal immune system in reproductive success in humans remains controversial. Here we focus on the events that occur in the maternal decidua during the first few weeks of human pregnancy, because this is the site at which maternal leukocytes initially interact with and can recognize fetal trophoblast cells, potentially involving allorecognition by both T cells and natural killer (NK) cells. NK cells are the dominant leukocyte population in first-trimester decidua, and genetic studies point to a role of allorecognition by uterine NK cells in establishing a boundary between the mother and the fetus. By contrast, definitive evidence that allorecognition by decidual T cells occurs during the first trimester is lacking. Thus, our view is that during the crucial period when the placenta is established, damaging T cell-mediated adaptive immune responses towards placental trophoblast are minimized, whereas NK cell allorecognition contributes to successful implantation and healthy pregnancy.

HLA sharing and maternal HLA expression in couples with recurrent pregnancy loss in Taiwan

OBJECTIVE

The aim of this study is to investigate the frequency and distribution of human HLA sharing and maternal HLA allele expression in couples with recurrent pregnancy loss in Taiwan.

MATERIALS AND METHODS

We retrospectively reviewed couples experienced two or more pregnancy loss before 20th weeks of gestation from March 2014 to November 2020 having HLA determination. Fertile individuals with one or more live-birth offspring receiving HLA allele determination during the same period were included as the control group. The distribution and frequency of HLA sharing were analyzed and presented by descriptive statistics. Fisher Exact Test were used to analyze specific maternal and paternal HLA allele comparing individuals with RPL to fertile group. P-value < 0.05 was thought to be statistically significant.

RESULTS

72 couples were enrolled from March 2014 to November 2020. Regarding the distribution of HLA sharing, HLA sharing between females and their male partners less and equal to 2 pairs were found in 40.3% of the couples. HLA sharing greater and equal to 3 pairs are found in 59.8% couples. HLA sharing was most frequently found in alleles HLA-A02, A11, DQ07, C07 and B60 in descending order. There was a significant lower expression of HLA-B13 in women with RPL compared to women who had successful pregnancy (p = 0.0234). Compared infertile men with fertile men cohort, the frequency of HLA-DR04 (p = 0.0438, OR 2.444, 95% CI 1.0251-5.8287), HLA-DR12 (p = 0.001, OR 30.85, 95% CI 4.0296-236.19) and HLA-15 (p = 0.0357, OR 9.354, 95% CI 1.1610-75.37) were found to be significantly higher in men with RPL. On the contrary, HLA-DR07 (p = 0.0085, OR 0.124, 95% CI 0.0264-0.587) and HLA-DR10 (p = 0.0395, OR 0.048, 95% CI 0.0027-0.8641) were found to be significantly lower in men with RPL.

CONCLUSION

We found a tendency to recurrent pregnancy loss in couples with more than 2 pairs of HLA sharing. The similarity of HLA sharing, the expression of maternal HLA-B13 allele and paternal HLA-DR alleles in Taiwanese couples might play a role in recurrent pregnancy loss.

What is the impact of sex hormones on the pathogenesis of rheumatoid arthritis?

Rheumatoid arthritis (RA) is the most common inflammatory rheumatic disease and has a female predominance of around 3:1. The relationship between sex hormones and RA has been of great interest to researchers ever since Philip Hench's observations in the 1930's regarding spontaneous disease amelioration in pregnancy. Extensive basic scientific work has demonstrated the immunomodulatory actions of sex hormones but this therapeutic potential has not to date resulted in successful clinical trials in RA. Epidemiological data regarding both endogenous and exogenous hormonal factors are inconsistent, but declining estrogen and/or progesterone levels in the menopause and post-partum appear to increase the risk and severity of RA. This review assimilates basic scientific, epidemiological and clinical trial data to provide an overview of the current understanding of the relationship between sex hormones and RA, focusing on estrogen, progesterone and androgens.

Coronavirus and Pregnancy: The Challenges of the 21st Century: A Review

Despite many advances in medicine we are still faced with emerging pathogens. Pregnant women have been disproportionately affected by previous coronavirus outbreaks. The COVID-19 pandemic has not affected pregnant women as greatly as SARS-CoV and MERS, but has posed other challenges such as the need for quarantine and isolation, limited access to antenatal care, use of personal protective equipment (PPE), vaccine hesitancy and inequities in vaccine access and therapeutics between rich countries and the global south. This review will describe the impact of the significant coronaviruses on pregnancy, with special focus on the challenges being encountered by the SARS-CoV-2 global pandemic.

Urticaria in Pregnancy and Lactation

Chronic urticaria (CU) is a mast cell-driven chronic inflammatory disease with a female predominance. Since CU affects mostly females in reproductive age, pregnancy is an important aspect to consider in the context of this disease. Sex hormones affect mast cell (MC) biology, and the hormonal changes that come with pregnancy can modulate the course of chronic inflammatory conditions, and they often do. Also, pregnancy-associated changes in the immune system, including local adaptation of innate and adaptive immune responses and skewing of adaptive immunity toward a Th2/Treg profile have been linked to changes in the course of inflammatory diseases. As of now, little is known about the effects of pregnancy on CU and the outcomes of pregnancy in CU patients. Also, there are no real-life studies to show the safety of urticaria medications during pregnancy. The recent PREG-CU study provided the first insights on this and showed that CU improves during pregnancy in half of the patients, whereas it worsens in one-third; and two of five CU patients experience flare-ups of their CU during pregnancy. The international EAACI/GA2LEN/EuroGuiDerm/APAAACI guideline for urticaria recommends adopting the same management strategy in pregnant and lactating CU patients; starting treatment with standard doses of second-generation (non-sedative) H1 antihistamines, to increase the dose up to 4-folds in case of no response, and to add omalizumab in antihistamine-refractory patients; but also emphasizes the lack of evidence-based information on the safety and efficacy of urticaria treatments during pregnancy. The PREG-CU study assessed treatments and their outcomes during pregnancy. Here, we review the reported effects of sex hormones and pregnancy-specific immunological changes on urticaria, we discuss the impact of pregnancy on urticaria, and we provide information and guidance on the management of urticaria during pregnancy and lactation.

A Comprehensive Investigation into the Distribution of Circulating B Cell Subsets in the Third Trimester of Pregnancy

Maternal B cells play a crucial role in the development and maintenance of pregnancy, due to their humoral activities and regulatory functions. In the study, we investigated the alterations in the distributions of naïve and memory B cell subsets, as well as regulatory B (Breg) cells, in the third trimester of pregnancy. Peripheral blood from 14 healthy pregnant women in the third trimester and 7 healthy non-pregnant women was collected and examined for the frequencies of B cell subsets, including IgD⁺CD27⁻ naïve, IgD⁺CD27⁺ un-switched memory, IgD⁻CD27⁺ switched memory, CD38^intCD24^int mature–naïve, CD38⁻CD24^hi primarily memory and CD38^hiCD24^hi transitional B cells by flow cytometry. Breg cell subsets were also characterized based on the expression of CD5, CD1d and IL-10. In pregnant women, the proportions of un-switched memory and transitional B cells were significantly decreased. Additionally, the frequencies of both CD5⁺CD1d⁺ Breg and IL-10-producing B10 cells were decreased in pregnancy. Changes in the distribution of transitional B cells as well as Breg cells may be crucial contributors for the development of altered maternal immune responses and tolerance needed for the maintenance of normal pregnancy in the third trimester.

Chronic Inflammatory Placental Disorders Associated With Recurrent Adverse Pregnancy Outcome

Chronic inflammatory placental disorders are a group of rare but devastating gestational syndromes associated with adverse pregnancy outcome. This review focuses on three related conditions: villitis of unknown etiology (VUE), chronic histiocytic intervillositis (CHI) and massive perivillous fibrin deposition (MPFD). The hallmark of these disorders is infiltration of the placental architecture by maternal immune cells and disruption of the intervillous space, where gas exchange between the mother and fetus occurs. Currently, they can only be detected through histopathological examination of the placenta after a pregnancy has ended. All three are associated with a significant risk of recurrence in subsequent pregnancies. Villitis of unknown etiology is characterised by a destructive infiltrate of maternal CD8+ T lymphocytes invading into the chorionic villi, combined with activation of fetal villous macrophages. The diagnosis can only be made when an infectious aetiology has been excluded. VUE becomes more common as pregnancy progresses and is frequently seen with normal pregnancy outcome. However, severe early-onset villitis is usually associated with fetal growth restriction and recurrent pregnancy loss. Chronic histiocytic intervillositis is characterised by excessive accumulation of maternal CD68+ histiocytes in the intervillous space. It is associated with a wide spectrum of adverse pregnancy outcomes including high rates of first-trimester miscarriage, severe fetal growth restriction and late intrauterine fetal death. Intervillous histiocytes can also accumulate due to infection, including SARS-CoV-2, although this infection-induced intervillositis does not appear to recur. As with VUE, the diagnosis of CHI requires exclusion of an infectious cause. Women with recurrent CHI and their families are predisposed to autoimmune diseases, suggesting CHI may have an alloimmune pathology. This observation has driven attempts to prevent CHI with a wide range of maternal immunosuppression. Massive perivillous fibrin deposition is diagnosed when >25% of the intervillous space is occupied by fibrin, and is associated with fetal growth restriction and late intrauterine fetal death. Although not an inflammatory disorder per se, MPFD is frequently seen in association with both VUE and CHI. This review summarises current understanding of the prevalence, diagnostic features, clinical consequences, immune pathology and potential prophylaxis against recurrence in these three chronic inflammatory placental syndromes.

Functional and structural modifications of influenza antibodies during pregnancy

Pregnancy represents a unique tolerogenic immune state which may alter susceptibility to infection and vaccine response. Here, we characterized humoral immunity to seasonal influenza vaccine strains in pregnant and non-pregnant women. Although serological responses to influenza remained largely intact during late pregnancy, distinct modifications were observed. Pregnant women had reduced hemagglutinin subtype-1 (H1)- IgG, IgG1, IgG2, and IgG3, hemagglutination inhibition, and group 1 and 2 stem IgG titers. Intriguingly, H1-specific avidity and FcγR1 binding increased, and influenza antibodies had distinct Fc and Fab glycans characterized by increased di-galactosylation and di-sialylation. H1-specific Fc-functionality (i.e. monocyte phagocytosis and complement deposition) was moderately reduced in pregnancy. Multivariate antibody analysis revealed two distinct populations (pregnant vs. non-pregnant) segregated by H1 FcγR1 binding, H1-IgG levels, and Fab and Fc glycosylation. Our results demonstrated a structural and functional modulation of influenza humoral immunity during pregnancy that was antigen-specific and consistent with reduced inflammation and efficient placental transport

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Pregnancy resulted in structural and functional modulation of influenza antibodies.

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Antibodies had differential binding capacity, Fc/Fab glycosylation, and function.

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Antibody glycans directed toward low inflammation and efficient placental transfer.

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Multivariate analysis of immune markers segregated pregnant and non-pregnant women.

Pregnancy and Management in Women with Rheumatoid Arthritis, Systemic Lupus Erythematosus, and Obstetric Antiphospholipid Syndrome

Management of women with rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), and obstetric antiphospholipid syndrome (APS) during pregnancy presents unique clinical challenges. Women with both RA and SLE can have disease flares during pregnancy, leading to pregnancy complications, such as preeclampsia, small-for-gestational-age infants, and preterm delivery. Disease should be under control prior to conception. Women with obstetric APS need to be anticoagulated during pregnancy. Many but not all antirheumatic medications can be used during pregnancy and lactation.

Sex Differences in Biological Systems and the Conundrum of Menopause: Potential Commonalities in Post-Menopausal Disease Mechanisms

Sex-specific differences in biology and physiology likely start at the time of conception and progress and mature during the pre-puberty time frame and then during the transitions accompanying puberty. These sex differences are impacted by both genetics and epigenetic alterations during the maturation process, likely for the purpose of preparing for successful reproduction. For females, later in life (~45–50) they undergo another transition leading to a loss of ovarian hormone production at menopause. The reasons for menopause are not clear, but for a subset of females, menopause is accompanied by an increased risk of a number of diseases or conditions that impact a variety of tissues. Most research has mainly focused on the target cells in each of the affected tissues rather than pursue the alternative option that there may be commonalities in the development of these post-menopausal conditions in addition to influences on specific target cells. This review will address some of the potential commonalities presented by an integration of the literature regarding tissue-specific aspects of these post-menopausal conditions and data presented by space flight/microgravity (a condition not anticipated by evolution) that could implicate a loss of a regulatory function of the microvasculature in the risk attached to the affected tissues. Thus, the loss of the integration of the paracrine relationships between endothelial cells of the microvasculature of the tissues affected in the post-menopausal environment could contribute to the risk for post-menopausal diseases/conditions. The validation of this concept could lead to new approaches for interventions to treat post-menopausal conditions, as well as provide new understanding regarding sex-specific biological regulation.

Beyond Systemic Lupus Erythematosus and Anti-Phospholipid Syndrome: The Relevance of Complement From Pathogenesis to Pregnancy Outcome in Other Systemic Rheumatologic Diseases

Evidence about the relevance of the complement system, a highly conserved constituent of the innate immunity response that orchestrates the elimination of pathogens and the inflammatory processes, has been recently accumulated in many different rheumatologic conditions. In rheumatoid arthritis, complement, mainly the classical pathway, contributes to tissue damage especially in seropositive subjects, with complement activation occurring in the joint. Data about complement pathways in psoriatic arthritis are dated and poorly consistent; among patients with Sjögren syndrome, hypocomplementemia exerts a prognostic role, identifying patients at risk of extra-glandular manifestations. Hints about complement involvement in systemic sclerosis have been recently raised, following the evidence of complement deposition in affected skin and in renal samples from patients with scleroderma renal crisis. In vasculitides, complement plays a dual role: on one hand, stimulation of neutrophils with anti-neutrophil cytoplasmic antibodies (ANCA) results in the activation of the alternative pathway, on the other, C5a induces translocation of ANCA antigens, favouring the detrimental role of antibodies. Complement deposition in the kidneys identifies patients with more aggressive renal disease; patients with active disease display low serum levels of C3 and C4. Even though in dermatomyositis sC5b-9 deposits are invariably present in affected muscles, data on C3 and C4 fluctuation during disease course are scarce. C3 and C1q serum levels have been explored as potential markers of disease activity in Takayasu arteritis, whereas data in Behçet disease are limited to in vitro observations. Pregnancies in women with rheumatologic conditions are still burdened by a higher rate of pregnancy complications, thus the early identification of women at risk would be invaluable. A fine-tuning of complement activation is required from a physiological progression of pregnancy, from pre-implantation stages, through placentation to labour. Complement deregulation has been implicated in several pregnancy complications, such as recurrent abortion, eclampsia and premature birth; low complement levels have been shown to reliably identify women at risk of complications. Given its physiologic role in orchestrating pregnancy progression and its involvement as pathogenic effector in several rheumatologic conditions, complement system is an attractive candidate biomarker to stratify the obstetric risk among women with rheumatologic conditions.

ROS-mediated liposomal dexamethasone: a new FA-targeted nanoformulation to combat rheumatoid arthritis via inhibiting iRhom2/TNF-α/BAFF pathways

Rheumatoid arthritis (RA) is an autoimmune inflammatory disorder that has seriously affected human health worldwide and its current management requires more successful therapeutic approaches. The combination of nanomedicines and pathophysiology into one system may provide an alternative strategy for precise RA treatment. In this work, a practical ROS-mediated liposome, abbreviated as Dex@FA-ROS-Lips that comprised synthetic dimeric thioether lipids (di-S-PC) and a surface functionalized with folic acid (FA), was proposed for dexamethasone (Dex) delivery. Incorporation with thioether lipids and a FA segment significantly improved the triggered release and improved the triggered release of cytotoxic Dex as well as the active targeting of RA, altering its overall pharmacokinetics and safety profiles in vivo. As proof, the designed Dex@FA-ROS-Lips demonstrated effective internalization by LPS-activated Raw264.7 macrophages with FA receptor overexpression and released Dex at the inflammatory site due to the ROS-triggered disassembly. Intravenous injection of this Dex@FA-ROS-Lips into adjuvant-induced arthritis (AIA) mice led to its incremental accumulation in inflamed joint tissues and significantly alleviated the cartilage destruction and joint swelling via suppression of proinflammatory cytokines (iRhom2, TNF-α and BAFF), as compared to the effect of commercial free Dex. Importantly, the Dex@FA-ROS-Lips nanoformulation showed better hemocompatibility with less adverse effects on the body weight and immune organ index of AIA mice. The anti-inflammatory mechanism of Dex@FA-ROS-Lips was further studied and it was found that it is possibly associated with the down-regulation of iRhom2 and the activation of the TNF-α/BAFF signaling pathway. Therefore, the integration of nanomedicines and the RA microenvironment using multifunctional Dex@FA-ROS-Lips shall be a novel RA treatment modality with full clinical potential, and based on the enhanced therapeutic effect, the signaling pathway of iRhom2/TNF-α/BAFF reasonably explained the mechanism of Dex@FA-ROS-Lips in anti-RA, which suggested a molecular target for RA therapy and other inflammatory diseases.

Pregnancy outcomes in relation to disease activity and anti-rheumatic treatment strategies in women with rheumatoid arthritis

OBJECTIVES

To explore the association of maternal rheumatoid arthritis (RA) to pregnancy outcomes, especially preterm birth (PTB) and small for gestational age (SGA), in relation to disease activity and anti-rheumatic treatment before and during pregnancy.

METHODS

By linking prospective clinical rheumatology registers (CRR) in Sweden (SRQ) and Denmark (DANBIO) with medical birth registers, we identified 1,739 RA-pregnancies and 17 390 control-pregnancies (matched 1:10 on maternal age, birth year, parity) with delivery 2006-2018. Disease activity (DAS28, CRP, HAQ-score) and anti-rheumatic treatment nine months before and during pregnancy were identified through CRR and prescribed drug registers. Using logistic regression, we estimated adjusted odds ratios (aOR) with 95% confidence intervals (CI) for PTB and SGA overall and stratified by disease activity and anti-rheumatic treatment before and during pregnancy, adjusting for maternal characteristics.

RESULTS

We found increased aOR of PTB (1.92, 1.56-2.35) and SGA (1.93, 1.45-2.57) in RA-pregnancies vs control-pregnancies. For RA-pregnancies with DAS28-CRP ≥ 4.1 vs < 3.2 during pregnancy, aOR was 3.38 (1.52-7.55) for PTB and 3.90 (1.46-10.4) for SGA. Use of oral corticosteroids (yes/no) during pregnancy resulted in an aOR of 2.11 (0.94-4.74) for PTB. Corresponding figure for biologics was 1.38 (0.66-2.89). Combination therapy, including biologics before pregnancy, was a marker of increased risk of both PTB and SGA.

CONCLUSION

During pregnancy, disease activity rather than treatment seems to be the most important risk factor for PTB and SGA in RA. Women with RA should be carefully monitored during pregnancy, especially if they have moderate to high disease activity or/and are treated with extensive anti-rheumatic treatment.

The Genetic, Environmental, and Immunopathological Complexity of Autoantibody-Negative Rheumatoid Arthritis

Differences in clinical presentation, response to treatment, and long-term outcomes between autoantibody-positive and -negative rheumatoid arthritis (RA) highlight the need for a better comprehension of the immunopathogenic events underlying the two disease subtypes. Whilst the drivers and perpetuators of autoimmunity in autoantibody-positive RA have started to be disclosed, autoantibody-negative RA remains puzzling, also due its wide phenotypic heterogeneity and its possible misdiagnosis. Genetic susceptibility appears to mostly rely on class I HLA genes and a number of yet unidentified non-HLA loci. On the background of such variable genetic predisposition, multiple exogeneous, endogenous, and stochastic factors, some of which are not shared with autoantibody-positive RA, contribute to the onset of the inflammatory cascade. In a proportion of the patients, the immunopathology of synovitis, at least in the initial stages, appears largely myeloid driven, with abundant production of proinflammatory cytokines and only minor involvement of cells of the adaptive immune system. Better understanding of the complexity of autoantibody-negative RA is still needed in order to open new avenues for targeted intervention and improve clinical outcomes.

Maternal Monocytes Respond to Cell-Free Fetal DNA and Initiate Key Processes of Human Parturition

Throughout gestation, the maternal immune system is tightly modulated to allow growth of a semiallogeneic fetus. During the third trimester, the maternal immune system shifts to a proinflammatory phenotype in preparation for labor. What induces this shift remains unclear. Cell-free fetal DNA (cffDNA) is shed by the placenta and enters maternal circulation throughout pregnancy. Levels of cffDNA are increased as gestation progresses and peak before labor, coinciding with a shift to proinflammatory maternal immunity. Furthermore, cffDNA is abnormally elevated in plasma from women with complications of pregnancy, including preterm labor. Given the changes in maternal immunity at the end of pregnancy and the role of sterile inflammation in the pathophysiology of spontaneous preterm birth, we hypothesized that cffDNA can act as a damage-associated molecular pattern inducing an inflammatory cytokine response that promotes hallmarks of parturition. To test this hypothesis, we stimulated human maternal leukocytes with cffDNA from primary term cytotrophoblasts or maternal plasma and observed significant IL-1β and CXCL10 secretion, which coincides with phosphorylation of IFN regulatory factor 3 and caspase-1 cleavage. We then show that human maternal monocytes are crucial for the immune response to cffDNA and can activate bystander T cells to secrete proinflammatory IFN-γ and granzyme B. Lastly, we find that the monocyte response to cffDNA leads to vascular endothelium activation, induction of myometrial contractility, and PGE₂ release in vitro. Our results suggest that the immune response to cffDNA can promote key features of the parturition cascade, which has physiologic consequences relevant to the timing of labor.

Rift Valley Fever Virus Propagates in Human Villous Trophoblast Cell Lines and Induces Cytokine mRNA Responses Known to Provoke Miscarriage

The mosquito-borne Rift Valley fever (RVF) is a prioritised disease that has been listed by the World Health Organization for urgent research and development of counteraction. Rift Valley fever virus (RVFV) can cause a cytopathogenic effect in the infected cell and induce hyperimmune responses that contribute to pathogenesis. In livestock, the consequences of RVFV infection vary from mild symptoms to abortion. In humans, 1–3% of patients with RVFV infection develop severe disease, manifested as, for example, haemorrhagic fever, encephalitis or blindness. RVFV infection has also been associated with miscarriage in humans. During pregnancy, there should be a balance between pro-inflammatory and anti-inflammatory mediators to create a protective environment for the placenta and foetus. Many viruses are capable of penetrating that protective environment and infecting the foetal–maternal unit, possibly via the trophoblasts in the placenta, with potentially severe consequences. Whether it is the viral infection per se, the immune response, or both that contribute to the pathogenesis of miscarriage remains unknown. To investigate how RVFV could contribute to pathogenesis during pregnancy, we infected two human trophoblast cell lines, A3 and Jar, representing normal and transformed human villous trophoblasts, respectively. They were infected with two RVFV variants (wild-type RVFV and RVFV with a deleted NSs protein), and the infection kinetics and 15 different cytokines were analysed. The trophoblast cell lines were infected by both RVFV variants and infection caused upregulation of messenger RNA (mRNA) expression for interferon (IFN) types I–III and inflammatory cytokines, combined with cell line-specific mRNA expression of transforming growth factor (TGF)-β1 and interleukin (IL)-10. When comparing the two RVFV variants, we found that infection with RVFV lacking NSs function caused a hyper-IFN response and inflammatory response, while the wild-type RVFV suppressed the IFN I and inflammatory response. The induction of certain cytokines by RVFV infection could potentially lead to teratogenic effects that disrupt foetal and placental developmental pathways, leading to birth defects and other pregnancy complications, such as miscarriage.

A case report of a severe neonatal systemic vasculitis on the first day of life

BACKGROUND

Neonatal systemic vasculitis syndromes have been reported in infants born to mothers with systemic lupus erythematosus, Sjögren's syndrome, Behҫet's disease, cutaneous polyarteritis nodosa and anti-neutrophil cytoplasmic antibody-associated vasculitides. Here we report a novel association of a case of new-onset maternal seronegative inflammatory arthritis associated with a transient systemic vasculitis in a neonate.

CASE PRESENTATION

In the first 24 h of life, a preterm Caucasian baby boy was noted to have blue discoloration to all four extremities. Despite antibiotics, fresh frozen plasma and anticoagulation, the discoloration remained, particularly in the left index finger. This was associated with fever and a maximum C-reactive protein (CRP) of 148 mg/L. Intravenous immunoglobulin (IVIG) was given with short-term improvement. Initial echocardiogram showed enlarged coronary arteries with normalization on repeat 1 week later. Clinical signs and symptoms responded to high dose oral steroid administration. MRI angiography (MRA) of the body and heart showed tortuosity of arteries in the upper and lower extremities with gadolinium uptake, suggestive of vasculitis. Autoantibody profile negative. Genetic panel for hereditary autoinflammatory diseases was negative as was whole exome sequencing performed on the trio. The baby was weaned off steroids by 5 months of age. A small distal autoamputation of the left index finger occurred. He was born to a 28-year-old woman who developed new onset severe symmetrical polyarthritis at 8 weeks gestation. This was presumed a reactive arthritis secondary to a dental infection. Infectious work up and autoantibodies were negative. She was treated with high dose prednisone for the remainder of her pregnancy. The mother was weaned off prednisone, treated with hydroxychloroquine for 8 months post-partum and remains in remission. A repeat MRA done at 1 year old showed mild residual tortuosities of the arteries in the forearms. The remainder of the medium and large vessels were within normal limits with no gadolinium enhancement to suggest active disease. The child is now 4 years old with normal growth and development.

CONCLUSION

This is a unique case of new-onset seronegative presumed reactive arthritis in a mother with the rare development of a successfully treated medium vessel vasculitis in an infant.

The systemic inflammatory landscape of COVID-19 in pregnancy: Extensive serum proteomic profiling of mother-infant dyads with in utero SARS-CoV-2

While pregnancy increases the risk for severe COVID-19, the clinical and immunological implications of COVID-19 on maternal-fetal health remain unknown. Here, we present the clinical and immunological landscapes of 93 COVID-19 mothers and 45 of their SARS-CoV-2-exposed infants through comprehensive serum proteomics profiling for >1,400 cytokines of their peripheral and cord blood specimens. Prenatal SARS-CoV-2 infection triggers NF-κB-dependent proinflammatory immune activation. Pregnant women with severe COVID-19 show increased inflammation and unique IFN-λ antiviral signaling, with elevated levels of IFNL1 and IFNLR1. Furthermore, SARS-CoV-2 infection re-shapes maternal immunity at delivery, altering the expression of pregnancy complication-associated cytokines, inducing MMP7, MDK, and ESM1 and reducing BGN and CD209. Finally, COVID-19-exposed infants exhibit induction of T cell-associated cytokines (IL33, NFATC3, and CCL21), while some undergo IL-1β/IL-18/CASP1 axis-driven neonatal respiratory distress despite birth at term. Our findings demonstrate COVID-19-induced immune rewiring in both mothers and neonates, warranting long-term clinical follow-up to mitigate potential health risks.

The Misattributed and Silent Causes of Poor COVID-19 Outcomes Among Pregnant Women

Abundant evidence strongly suggests that the condition of pregnancy makes women and their fetuses highly vulnerable to severe Corona-virus 2019 (COVID-19) complications. Here, two novel hypoxia-related conditions are proposed to play a pivotal role in better understanding the relationship between COVID-19, pregnancy and poor health outcomes. The first condition, "misattributed dyspnea (shortness of breath)" refers to respiratory symptoms common to both advanced pregnancy and COVID-19, which are mistakenly perceived as related to the former rather than to the latter; as a result, pregnant women with this condition receive no medical attention until the disease is in an advanced stage. The second condition, "silent hypoxia", refers to abnormally low blood oxygen saturation levels in COVID-19 patients, which occur in the absence of typical respiratory distress symptoms, such as dyspnea, thereby also leading to delayed diagnosis and treatment. The delay in diagnosis and referral to treatment, due to either "misattributed dypsnea" or "silent hypoxia", may lead to rapid deterioration and poor health outcome to both the mothers and their fetuses. This is particularly valid among women during advanced stages of pregnancy as the altered respiratory features make the consequences of the disease more challenging to cope with. Studies have demonstrated the importance of monitoring blood oxygen saturation by pulse oximetry as a reliable predictor of disease severity and outcome among COVID-19 patients. We propose the use of home pulse oximetry during pregnancy as a diagnostic measure that, together with proper medical guidance, may allow early diagnosis of hypoxia and better health outcomes.