In vivo immune signatures of healthy human pregnancy: Inherently inflammatory or anti-inflammatory?

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.

Parental Preconception Posttraumatic Stress Symptoms and Maternal Prenatal Inflammation Prospectively Predict Shorter Telomere Length in Children

OBJECTIVE

Parental trauma exposure and trauma-related distress can increase the risk of adverse health outcomes in offspring, but the pathways implicated in intergenerational transmission are not fully explicated. Accelerated biological aging may be one mechanism underlying less favorable health in trauma-exposed individuals and their offspring. This study examines the associations of preconception maternal and paternal posttraumatic stress disorder (PTSD) symptoms with child telomere length, and maternal prenatal C-reactive protein (CRP) as a biological mechanism.

METHODS

Mothers ( n = 127) and a subset of the fathers ( n = 84) reported on PTSD symptoms before conception. Mothers provided blood spots in the second and third trimesters that were assayed for CRP. At age 4 years, children provided buccal cells for measurement of telomere length. Models adjusted for parental age, socioeconomic status, maternal prepregnancy body mass index, child biological sex, and child age.

RESULTS

Mothers' PTSD symptoms were significantly associated with shorter child telomere length ( β = -0.22, SE = 0.10, p = .023). Fathers' PTSD symptoms were also inversely associated with child telomere length ( β = -0.21, SE = 0.11), although nonsignificant ( p = .065). There was no significant indirect effect of mothers' PTSD symptoms on child telomere length through CRP in pregnancy, but higher second-trimester CRP was significantly associated with shorter child telomere length ( β = -0.35, SE = 0.18, p = .048).

CONCLUSIONS

Maternal symptoms of PTSD before conception and second-trimester inflammation were associated with shorter telomere length in offspring in early childhood, independent of covariates. Findings indicate that intergenerational transmission of parental trauma may occur in part through accelerated biological aging processes and provide further evidence that prenatal proinflammatory processes program child telomere length.Open Science Framework Preregistration:https://osf.io/7c2d5/?view_only=cd0fb81f48db4b8f9c59fc8bb7b0ef97 .

Is it possible to identify COVID-19 infection-related biomarkers during pregnancy?: A prospective study in Turkish population

The coronavirus disease 2019 (COVID-19) has raised concerns about the potential complications it may cause in pregnant women. Therefore, biomarkers that can predict the course of COVID-19 in pregnant women may be of great benefit as they would provide valuable insights into the prognosis and, thus, the management of the disease. In this context, the objective of this study is to identify the biomarkers that can predict COVID-19 progression in pregnant women, focusing on composite hemogram parameters and systemic inflammatory and spike markers. The population of this single-center prospective case-control study consisted of all consecutive pregnant women with single healthy fetuses who tested positive for COVID-19 and who were admitted to Bakirköy Dr Sadi Konuk Training and Research Hospital in Istanbul, Turkey, a COVID-19 referral hospital, between April 2020 and March 2021, with an obstetric indication, during their second or third trimester. The control group consisted of consecutive pregnant women with a single healthy fetus who were admitted to the same hospital within the same date range, had demographic and obstetric characteristics matching the patient group, but tested negative for COVID-19. The patient and control groups were compared in terms of platelet-to-lymphocyte ratio (PLR), platelet-to-neutrophil ratio (PNR), and neutrophil-to-lymphocyte ratio (NLR), and systemic inflammatory and spike markers, including C-reactive protein (CRP), interleukin-6 (IL-6), interleukin-10 (IL-10), cluster of differentiation 26 (CD26), and B7 homolog 4 (B7H4). There were 45 (51.1%) and 43 (48.8%) pregnant women in the patient and control groups, respectively. There was no significant difference between the groups in demographic and obstetric characteristics (P > .05). The PNR, PLR, and CRP values were significantly higher in the patient group than in the control group (P < .05). On the other hand, there was no significant difference between the groups in IL-6, IL-10, CD26, and B7H4 levels (P > .05). The findings of our study showed that specific inflammatory markers, such as CRP, PLR, and PNR, can potentially predict the course of COVID-19 in pregnant women. However, more comprehensive, well-controlled studies are needed to corroborate our study's findings and investigate other potential inflammatory markers.

Association between maternal cardiometabolic markers and fetal growth in non-complicated pregnancies: a secondary analysis of the PRINCESA cohort

The objective of this study was to evaluate the association of maternal cardiometabolic markers trajectories (glucose, triglycerides (TG), total cholesterol, systolic blood pressure (SBP) and diastolic blood pressure (DBP)) with estimated fetal weight trajectories and birth weight in Mexican pregnant women without medical complications. Cardiometabolic marker trajectories were characterized using group-based trajectory models. Mixed-effect and linear regression models were estimated to assess the association of maternal trajectories with estimated fetal weight and birth weight. The final sample comprised 606 mother-child dyads. Two trajectory groups of maternal cardiometabolic risk indicators during pregnancy were identified (high and low). Fetuses from women with higher values of TG had higher weight gain during pregnancy ( β ^  = 24.00 g; 95%CI: 12.9, 35.3), were heavier at the sixth month ( β ^ =48.24 g; 95%CI: 7.2, 89.7) and had higher birth weight ( β ^ = 89.08 g; 95%CI: 20.8, 157.4) than fetuses in the low values trajectory. Fetuses from mothers with high SBP and DBP had less weight in the sixth month of pregnancy ( β ^ = - 42.4 g; 95%CI: - 82.7, - 2.1 and β ^ = - 50.35 g; 95%CI: - 94.2, - 6.4), and a higher DBP trajectory was associated with lower birth weight ( β ^ = - 101.48 g; 95%CI: - 176.5, - 26.4). In conclusion, a longitudinal exposition to high values of TG and BP was associated with potentially adverse effects on fetal growth. These findings support the potential modulation of children's phenotype by maternal cardiometabolic conditions in pregnancies without medical complications.

Prenatal mood and anxiety disorders and associated cytokine changes

BACKGROUND

We examined whether women with prenatal mood and anxiety disorders would exhibit differential pro- and anti-inflammatory marker trajectories during the prenatal and postpartum periods compared to women without these disorders.

METHODS

Approximately 179 pregnant women participated in a longitudinal study conducted in two urban areas. Blood samples for inflammatory markers were collected at six study visits. The Structured Clinical Interview for the DSM-IV (SCID) was administered to participants scoring above cutoffs on anxiety and depression. Pregnant women with SCID Axis I diagnoses of mood and/or anxiety disorders were compared to other participants on inflammatory markers. Multilevel modeling tested associations between SCID diagnoses and within-person interleukin (IL)6 and IL10 trajectories.

RESULTS

Prenatal SCID diagnoses were associated with linear, quadratic and cubic change in IL6 from prenatal to postpartum timepoints. Women with a prenatal SCID diagnosis had steeper decreases and increases in IL6 during prenatal and postpartum periods. SCID diagnoses were associated with lower IL10 in mid-pregnancy to postpartum (b = -0.078, SE = 0.019; p = .015).

LIMITATIONS

Future studies would benefit from a larger sample size and a larger number of participants with SCID diagnoses. Future research should also examine whether different prenatal Axis 1 diagnoses are associated with different patterns of immune response in pregnancy.

CONCLUSIONS

Pregnant women with prenatal mood and anxiety disorders had greater fluctuations in IL6 across prenatal and postpartum periods and lower IL10 through pregnancy and postpartum. They may have different proinflammatory states that remain after birth without a reciprocal anti-inflammatory response.

Hs-CRP and TNF-α Effects on Postnatal Umbilical Coiling: Impact Assessment of the Gestational Diabetes Mellitus

Background

No study has been conducted to specifically demonstrate the relationship between gestational diabetes mellitus (GDM) status, inflammatory factors, and postnatal umbilical coiling index (pUCI). Understanding this relationship could help select the best interventions to save the fetus. To evaluate the effects of maternal venous and umbilical cord blood levels of high sensitivity C-reactive protein (hs-CRP) and tumor necrosis factor-alpha (TNF-alpha) on pUCI in GDM and non-GDM groups.

Methods

This prospective observational study included 40 participants in each of the GDM and non-GDM groups, matched for maternal age, ethnicity, and parity. The GDM diagnosis was confirmed by 24 to 28 weeks of gestation (WOG) and a 2-step strategy. The covariates of interest were maternal hs-CRP and TNF-α, measured at 37 to 40 WOG, and their UC analogous was measured during delivery. The gross morphologies were assessed immediately after delivery. The UC coiling was quantitatively assessed by the pUCI. To compare the GDM and non-GDM groups, the t test and the Mann-Whitney test were used for normal and non-normal variables, respectively.

Results

There was not a significant difference in hs-CRP and TNF-a levels in maternal venous blood or UC blood between the GDM and non-GDM groups. The mean (SD) of pUCI in the GDM and non-GDM groups were 0.28 (0.15) and 0.24 (0.21) (P = 0.441), respectively. In the GDM group, none of the 4 covariates of interest had significant effects on the UCI. Among the non-GDM participants, merely the UC hs-CRP had a direct association with the pUCI, with a Pearson correlation of 0.54 (P = 0.001). Impacts of hs-CRP and TNF-α on the pUCI were assessed using Poisson regression models and no significant findings were detected (95% CI, 0.999-1.001, for all parameters).

Conclusion

In the GDM group, no apparent association was observed between inflammatory factors and pUCI, although a direct association was detected between UC hs-CRP and pUCI in the non-GDM.

The dynamic inflammatory profile of pregnancy can be monitored using a novel lipid-based mass spectrometry technique

The lipid environment changes throughout pregnancy both physiologically with emergent insulin resistance and pathologically e.g., gestational diabetes mellitus (GDM). Novel mass spectrometry (MS) techniques applied to minimally processed blood might lend themselves to monitoring changing lipid profiles to inform care decisions across pregnancy. In this study we use an intact-sandwich, MALDI-ToF MS method to identify phosphatidylcholine (PC) and lysophosphatidylcholine (LPC) species and calculate their ratio as an indicator of inflammation. Plasma and sera were prepared from venous blood of non-pregnant women (aged 18-40) and pregnant women at 16 weeks, 28 weeks (including GDM-positive women), and 37+ weeks (term) of gestation alongside umbilical cord blood (UCB). Women with a normal menstrual cycle and age-matched men provided finger-prick derived capillary sera at 6 time-points over a month. Serum rather than plasma was preferable for PC/LPC measurement. As pregnancy progresses, an anti-inflammatory phenotype dominates the maternal circulation, evidenced by increasing PC/LPC ratio. In contrast, the PC/LPC ratio of UCB was aligned to that of non-pregnant donors. BMI had no significant effect on the PC/LPC ratio, but GDM-complicated pregnancies had significantly lower PC/LPC at 16 weeks of gestation. To further translate the use of the PC/LPC ratio clinically, the utility of finger-prick blood was evaluated; no significant difference between capillary versus venous serum was found and we revealed the PC/LPC ratio oscillates with the menstrual cycle. Overall, we show that the PC/LPC ratio can be measured simply in human serum and has the potential to be used as a time-efficient and less invasive biomarker of (mal)adaptative inflammation.

Breast Carcinogenesis during Pregnancy: Molecular Mechanisms, Maternal and Fetal Adverse Outcomes

Breast cancer is a common type of cancer diagnosed during pregnancy, with increasing incidence over the last years, as more women choose to delay childbearing. Compared to breast cancer in general population, pregnancy-associated breast cancer (PABC) is significantly different in its terms of epidemiology, diagnostic and therapeutic management, while it exhibits particularly aggressive behavior, deriving from its unique molecular and biological profile. Although not fully elucidated, the pathophysiological basis of PABC can be traced back to a combination of hormonal and immune changes during pregnancy, breast involution and altered gene expression. There is considerable controversy in the existing literature about the influence of PABC on pregnancy outcomes, regarding both short- and long-term effects on maternal and fetal/neonatal health. The majority of PABC patients have advanced-stage disease at initial diagnosis and face a significantly poorer prognosis, with decreased survival rates. The most commonly reported adverse obstetrical–fetal events are preterm delivery and prematurity-associated neonatal morbidity, while other neonatal treatment-associated complications might also occur, even when safe therapeutic options are applied during pregnancy. The objective of the present comprehensive review was to summarize current knowledge and up-to-date evidence about the pathophysiological, molecular and biological basis of PABC, as well as its association with adverse maternal, obstetrical, fetal and neonatal outcomes.

COVID-19 tanısı konmuş gebe kadınlarda proinflamatuar IL-6 ve antiinflamatuar IL-10 sitokinlerinin etkileri

ÖZ Amaç: Çalışmamızda COVID-19 pozitif gebelerde serum interlökin-6 ve interlökin-10 düzeyleri ile hastalığın seyri arasındaki ilişkinin araştırılması amaçlandı. Yöntemler: Çalışmamızda 28 üçüncü trimester COVID-19 pozitif gebe ve 30 üçüncü trimester sağlıklı gebede serum IL-6 ve IL-10 düzeyleri ölçüldü. COVID-19 pozitif vakalar, taşıyıcı veya hasta olarak sınıflandırıldı. Çalışma grubundaki gebelerden 13'ü asemptomatik iken veya hafif hastalık nedeniyle takip edilirken; 7'si yoğun bakımda (YBÜ) olmak üzere toplam 15 hamile kadın hastaneye kaldırılarak tedavi altına alındı. COVID-19 pozitif gebe kadınların IL-6 ve IL-10 testleri ilk uygulama sırasında çalışıldı. Bulgular: COVID-19'lu 7 (%25) hastanın yoğun bakım ünitesine kabul edilmesi gerekti. COVID-19 negatif gebelerde IL-6 düzeyi, COVID-19 taşıyıcısı ve hasta gebelere göre anlamlı derecede düşük bulundu (p=0,01). COVID-19 negatif olan gebelerde IL-10 düzeyi, COVID-19 taşıyıcısı olan gebelere (p=0,002) ve hastalara (p=0,002) göre anlamlı derecede yüksek bulundu. Sonuç: Şüpheli veya doğrulanmış bir COVID-19 teşhisi ile başvuran hamile kadınlarda olumsuz sonuç riskini en aza indirmek için IL-6 ve IL-10 sitokin düzeylerinin yakından izlenmesi önerilir. Bu şekilde hamile kadınlarda orta-hafif COVID-19'u şiddetli COVID-19'dan ayırt etmek mümkün olabilir.

Maternal body mass index is associated with an altered immunological profile at 28 weeks of gestation

Healthy pregnancy is accompanied by various immunological and metabolic adaptations. Maternal obesity has been implicated in adverse pregnancy outcomes such as miscarriage, preeclampsia, and gestational diabetes mellitus (GDM), while posing a risk to the neonate. There is a lack of knowledge surrounding obesity and the maternal immune system. The objective of this study was to consider if immunological changes in pregnancy are influenced by maternal obesity. Peripheral blood was collected from fasted GDM-negative pregnant women at 26-28 weeks of gestation. Analysis was done using immunoassay, flow cytometry, bioenergetics analysis, and cell culture. The plasma profile was significantly altered with increasing BMI, specifically leptin (r = 0.7635), MCP-1 (r = 0.3024), and IL-6 (r = 0.4985). Circulating leukocyte populations were also affected with changes in the relative abundance of intermediate monocytes (r = -0.2394), CD4:CD8 T-cell ratios (r = 0.2789), and NKT cells (r = -0.2842). Monocytes analysed in more detail revealed elevated CCR2 expression and decreased mitochondrial content with increased BMI. However, LPS-stimulated cytokine production and bioenergetic profile of PBMCs were not affected by maternal BMI. The Th profile skews towards Th17 with increasing BMI; Th2 (r = -0.3202) and Th9 (r = -0.3205) cells were diminished in maternal obesity, and CytoStim™-stimulation exacerbates IL-6 (r = 0.4166), IL-17A (r = 0.2753), IL-17F (r = 0.2973), and IL-22 (r = 0.2257) production with BMI, while decreasing IL-4 (r = -0.2806). Maternal obesity during pregnancy creates an inflammatory microenvironment. Successful pregnancy requires Th2-biased responses yet increasing maternal BMI favours a Th17 response that could be detrimental to pregnancy. Further research should investigate key populations of cells identified here to further understand the immunological challenges that beset pregnant women with obesity.

Longitudinal changes in serum immune markers during normal pregnancy in a North-Indian population

PROBLEM

The objective of this study was to examine levels of cytokines across normal term pregnancy in an Indian population. Additionally we have also explored for possible associations between inflammatory markers and fetal growth parameters.

METHOD OF STUDY

A multiplex panel of 24 analytes was used to examine levels of inflammatory markers in maternal serum at three time points during pregnancy and in cord blood from women with no reported comorbidities who delivered a singleton live baby at term (N = 23), enrolled in the GARBH-Ini pregnancy cohort. Linear mixed models were applied to construct longitudinal cytokine trajectories with gestational age. Pearson correlation was used to calculate intra-visit correlation between cytokines. Principal component analysis (PCA) was performed to examine cytokine combinations prevalent across pregnancy, and their association with fetal growth parameters was determined by multivariable regression.

RESULTS

Significant increase in sFLT-1, Flt3L, PLGF, IL-4, and IL-18 and a decrease in VCAM-1 concentrations was seen across pregnancy. The cytokine concentrations in cord blood differed substantially as compared to maternal levels across gestation. Some cytokines were closely correlated with each other in distinct patterns across pregnancy. Gestational age specific combination of cytokines were seen to be associated with different fetal growth parameters.

CONCLUSIONS

This study for the first time provides reference concentrations for the longitudinal expression of immune markers across pregnancy in an Indian population providing a much needed baseline to compare with pregnancies leading to adverse outcomes. Growth factors showed maximum longitudinal variation with gestational age and strong correlations were identified between various cytokines at all time points across pregnancy.

Maternal diet and obesity shape offspring central and peripheral inflammatory outcomes in juvenile non-human primates

The obesity epidemic affects 40% of adults in the US, with approximately one-third of pregnant women classified as obese. Previous research suggests that children born to obese mothers are at increased risk for a number of health conditions. The mechanisms behind this increased risk are poorly understood. Increased exposure to in-utero inflammation induced by maternal obesity is proposed as an underlying mechanism for neurodevelopmental alterations in offspring. Utilizing a non-human primate model of maternal obesity, we hypothesized that maternal consumption of an obesogenic diet will predict offspring peripheral (e.g., cytokines and chemokines) and central (microglia number) inflammatory outcomes via the diet's effects on maternal adiposity and maternal inflammatory state during the third trimester. We used structural equation modeling to simultaneously examine the complex associations among maternal diet, metabolic state, adiposity, inflammation, and offspring central and peripheral inflammation. Four latent variables were created to capture maternal chemokines and pro-inflammatory cytokines, and offspring cytokine and chemokines. Model results showed that offspring microglia counts in the basolateral amygdala were associated with maternal diet (β = -0.622, p < 0.01), adiposity (β = 0.593, p < 0.01), and length of gestation (β = 0.164, p < 0.05) but not with maternal chemokines (β = 0.135, p = 0.528) or maternal pro-inflammatory cytokines (β = 0.083, p = 0.683). Additionally, we found that juvenile offspring peripheral cytokines (β = -0.389, p < 0.01) and chemokines (β = -0.298, p < 0.05) were associated with a maternal adiposity-induced decrease in maternal circulating chemokines during the third trimester (β = -0.426, p < 0.01). In summary, these data suggest that maternal diet and adiposity appear to directly predict offspring amygdala microglial counts while maternal adiposity influences offspring peripheral inflammatory outcomes via maternal inflammatory state.

Perinatal mental illness and maternal autoimmune disease: A review of current evidence and avenues for future research

This review summarizes evidence on the association between perinatal mental illness and maternal autoimmune disease and identifies avenues for future research. Perinatal mental illness has several characteristics in common with autoimmune disease, including increased incidence in the early postpartum period, recurrence across pregnancies, evidence of elevated immune-mediated cytokines, and familial risk, as well as the general predominance of mental illness in females versus males. Several studies have demonstrated elevated risk of maternal autoimmune disease in women with perinatal mental illness, and of perinatal mental illness in those with autoimmune dysfunction, suggesting a bi-directional relationship. Further research is needed to elucidate the importance of the specific diagnosis, severity, and timing of perinatal mental illness and specific diagnosis of autoimmune disease, as well as the relative importance of perinatal versus non-perinatal mental illness. Such research could have implications for prevention, treatment, and follow-up of perinatal mental illness.

Placental Ultrasonographic Findings Due to COVID-19 Infection During Pregnancy: A Case Report

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection during pregnancy can lead to several adverse events. Here, we report a case of a 40-year-old Caucasian female, gravida 1, para 0, with a spontaneous singleton pregnancy, who presented to the emergency room during her 17th week of gestation with fever (38.8ºC), fatigue, shortness of breath, and palpitations. She tested positive for coronavirus disease 2019 (COVID-19). Ultrasonography examination revealed signs of placental involvement compatible with malperfusion, chorangiosis, deciduitis, and subchorionitis. Findings remained stable until the 20th week and gradually resolved around the 32nd week of pregnancy. A normal male neonate was delivered via elective caesarian section during the 39th week, weighing 2830 gm. The present report points toward a correlation between clinical symptomatology of COVID-19 during pregnancy and ultrasonographical features. Early detection of placental damage through the use of specific ultrasound findings could indicate which pregnancies are at increased risk for complications; however, further studies including a larger population are required to confirm these findings.

Immunometabolic adaptation and immune plasticity in pregnancy and the bi-directional effects of obesity

Mandatory maternal metabolic and immunological changes are essential to pregnancy success. Parallel changes in metabolism and immune function make immunometabolism an attractive mechanism to enable dynamic immune adaptation during pregnancy. Immunometabolism is a burgeoning field with the underlying principle being that cellular metabolism underpins immune cell function. With whole body changes to the metabolism of carbohydrates, protein and lipids well recognised to occur in pregnancy and our growing understanding of immunometabolism as a determinant of immunoinflammatory effector responses, it would seem reasonable to expect immune plasticity during pregnancy to be linked to changes in the availability and handling of multiple nutrient energy sources by immune cells. While studies of immunometabolism in pregnancy are only just beginning, the recognised bi-directional interaction between metabolism and immune function in the metabolic disorder obesity might provide some of the earliest insights into the role of immunometabolism in immune plasticity in pregnancy. Characterised by chronic low-grade inflammation including in pregnant women, obesity is associated with numerous adverse outcomes during pregnancy and beyond for both mother and child. Concurrent changes in metabolism and immunoinflammation are consistently described but any causative link is not well established. Here we provide an overview of the metabolic and immunological changes that occur in pregnancy and how these might contribute to healthy versus adverse pregnancy outcomes with special consideration of possible interactions with obesity.

Immune cell type and DNA methylation vary with reproductive status in women: possible pathways for costs of reproduction

Background

Consistent with evolutionarily theorized costs of reproduction (CoR), reproductive history in women is associated with life expectancy and susceptibility to certain cancers, autoimmune disorders and metabolic disease. Immunological changes originating during reproduction may help explain some of these relationships.

Methodology

To explore the potential role of the immune system in female CoR, we characterized leukocyte composition and regulatory processes using DNA methylation (DNAm) in a cross-sectional cohort of young (20–22 years old) women differing in reproductive status.

Results

Compared to nulliparity, pregnancy was characterized by differential methylation at 828 sites, 96% of which were hypomethylated and enriched for genes associated with T-cell activation, innate immunity, pre-eclampsia and neoplasia. Breastfeeding was associated with differential methylation at 1107 sites (71% hypermethylated), enriched for genes involved in metabolism, immune self-recognition and neurogenesis. There were no significant differences in DNAm between nulliparous and parous women. However, compared to nullipara, pregnant women had lower proportions of B, CD4T, CD8T and natural killer (NK) cells, and higher proportions of granulocytes and monocytes. Monocyte counts were lower and NK counts higher among breastfeeding women, and remained so among parous women.

Implications

Our findings point to widespread differences in DNAm during pregnancy and lactation. These effects appear largely transient, but may accumulate with gravidity become detectable as women age. Nulliparous and parous women differed in leukocyte composition, consistent with more persistent effects of reproduction on cell type. These findings support transient (leukocyte DNAm) and persistent (cell composition) changes associated with reproduction in women, illuminating potential pathways contributing to CoR.

Lay Summary: Evolutionary theory and epidemiology support costs of reproduction (CoR) to women’s health that may involve changes in immune function. We report differences in immune cell composition and gene regulation during pregnancy and breastfeeding. While many of these differences appear transient, immune cell composition may remain, suggesting mechanisms for female CoR.

Ambient air pollution and inflammatory effects in a Canadian pregnancy cohort

Supplemental Digital Content is available in the text.

Background:

Epidemiologic studies have consistently reported associations between air pollution and pregnancy outcomes including preeclampsia and gestational diabetes. However, the biologic mechanisms underlying these relationships remain unclear as few studies have collected relevant biomarker data. We examined relationships between ambient PM_2.5 and NO₂ with markers of inflammation during pregnancy in a prospective cohort of Canadian women.

Methods:

We analyzed data from 1170 women enrolled in the Maternal-Infant Research on Environmental Chemicals study. Daily residential PM_2.5 and NO₂ exposures during pregnancy were estimated using satellite-based and land-use regression models and used to create 14-day and 30-day exposure windows before blood-draw. Inflammatory markers C-reactive protein, interleukin-6, interleukin-8, and tumor necrosis factor-α were measured in third trimester plasma samples. Multivariable linear regression was used to estimate associations for an interquartile range (IQR) increase in PM_2.5 and NO₂ and markers of inflammation, while adjusting for individual-level confounders.

Results:

Fourteen-day (IQR: 6.85 µg/m³) and 30-day (IQR: 6.15 µg/m³) average PM_2.5 exposures before blood-draw were positively associated with C-reactive protein after adjustment for covariates (24.6% [95% CI = 9.4, 41.9] and 17.4% [95% CI = 1.0, 35.0] increases, respectively). This association was found to be robust in several sensitivity analyses. Neither PM_2.5 nor NO₂ exposures were associated with interleukin-6, interleukin-8, or tumor necrosis factor-α.

Conclusion:

Exposure to ambient PM_2.5 is positively associated with maternal inflammatory pathways in late pregnancy. This may contribute to positive associations between ambient PM_2.5 and risk of adverse pregnancy outcomes.

Inflammatory and immune marker trajectories from pregnancy to one-year post-birth

BACKGROUND

Pregnancy is an immunomodulatory state, with reported systematic changes in inflammatory and immune activity by pregnancy stage. Published data are inconsistent as to how inflammatory and immune markers change and recover across pregnancy and the postpartum period, or the sociodemographic, health and pregnancy-related factors that could affect biomarker trajectories. The purpose of this study is to describe inflammatory and immune marker trajectories from pregnancy to a year post-birth, and to test associations with sociodemographic, health and pregnancy-related variables.

METHODS

A sample of 179 pregnant women were assessed three times during pregnancy (between 8 and 36 weeks gestation) and three times during the postpartum period (between 1 and 12 months). Maternal sociodemographic characteristics, health, and pregnancy factors were obtained at study entry. Blood samples from each assessment were assayed for interleukin(IL)-6, tumor necrosis factor(TNF)α, IL-8, IL-10, and interferon(IFN)γ. Multilevel modelling was used to characterize biomarker trajectories and associations with sociodemographic and health variables.

RESULTS

Distinct trajectories over time emerged for each biomarker. Male pregnancies were associated with higher TNFα, IL-10, and IFNγ; higher pre-pregnancy BMI was associated with higher IL-6 and IFNγ. Nulliparity was associated with greater increases in IL-6 and TNFα.

CONCLUSIONS

Patterns observed for inflammatory and immune markers from pregnancy to a year postpartum support the hypothesis that the maternal immune system changes systematically across pregnancy and through an extended postpartum period. Parity, pre-pregnancy BMI and child sex are associated with inflammatory marker patterns over time. These results contribute to our understanding of how immune system activity changes from pregnancy to the post-birth period, and the factors that could affect those changes.

Neurological consequences of neurovascular unit and brain vasculature damages: potential risks for pregnancy infections and COVID-19-babies

Intragravidic and perinatal infections, acting through either direct viral effect or immune-mediated responses, are recognized causes of liability for neurodevelopmental disorders in the progeny. The large amounts of epidemiological data and the wealth of information deriving from animal models of gestational infections have contributed to delineate, in the last years, possible underpinning mechanisms for this phenomenon, including defects in neuronal migration, impaired spine and synaptic development, and altered activation of microglia. Recently, dysfunctions of the neurovascular unit and anomalies of the brain vasculature have unexpectedly emerged as potential causes at the origin of behavioral abnormalities and psychiatric disorders consequent to prenatal and perinatal infections. This review aims to discuss the up-to-date literature evidence pointing to the neurovascular unit and brain vasculature damages as the etiological mechanisms in neurodevelopmental syndromes. We focus on the inflammatory events consequent to intragravidic viral infections as well as on the direct viral effects as the potential primary triggers. These authors hope that a timely review of the literature will help to envision promising research directions, also relevant for the present and future COVID-19 longitudinal studies.

Maternal obesity and developmental programming of neuropsychiatric disorders: An inflammatory hypothesis

Maternal obesity is associated with the development of a variety of neuropsychiatric disorders; however, the mechanisms behind this association are not fully understood. Comparison between maternal immune activation and maternal obesity reveals similarities in associated impairments and maternal cytokine profile. Here, we present a summary of recent evidence describing how inflammatory processes contribute towards the development of neuropsychiatric disorders in the offspring of obese mothers. This includes discussion on how maternal cytokine levels, fatty acids and placental inflammation may interact with foetal neurodevelopment through changes to microglial behaviour and epigenetic modification. We also propose an exosome-mediated mechanism for the disruption of brain development under maternal obesity and discuss potential intervention strategies.

Innate Lymphoid Cells and Adaptive Immune Cells Cross-Talk: A Secret Talk Revealed in Immune Homeostasis and Different Inflammatory Conditions

The inflammatory immune response has evolved to protect the host from different pathogens, allergens, and endogenous death or damage-associated molecular patterns. Both innate and adaptive immune components are crucial in inducing an inflammatory immune response depending on the stimulus type and its duration of exposure or the activation of the primary innate immune response. As the source of inflammation is removed, the aggravated immune response comes to its homeostatic level. However, the failure of the inflammatory immune response to subside to its normal level generates chronic inflammatory conditions, including autoimmune diseases and cancer. Innate lymphoid cells (ILCs) are newly discovered innate immune cells, which are present in abundance at mucosal surfaces, including lungs, gastrointestinal tract, and reproductive tract. Also, they are present in peripheral blood circulation, skin, and lymph nodes. They play a crucial role in generating the pro-inflammatory immune response during diverse conditions. On the other hand, adaptive immune cells, including different types of T and B cells are major players in the pathogenesis of autoimmune diseases (type 1 diabetes mellitus, rheumatoid arthritis, psoriasis, and systemic lupus erythematosus, etc.) and cancers. Thus the article is designed to discuss the immunological role of different ILCs and their interaction with adaptive immune cells in maintaining the immune homeostasis, and during inflammatory autoimmune diseases along with other inflammatory conditions (excluding pathogen-induced inflammation), including cancer, graft-versus-host diseases, and human pregnancy.

Comprehensive analysis of COVID-19 during pregnancy

The COVID-19 pandemic resulting from the emergence of the coronavirus SARS-CoV-2 remains a major global health concern. Pregnant individuals are more likely to develop severe COVID-19 and a number of pregnancy complications have been observed in COVID-19 patients. To date, little is known about the impact of COVID-19 on pregnancy. In this review, we examine key aspects of pregnancy that may be impacted by COVID-19 and summarize the current literature on SARS-CoV-2 infection of the placenta and in utero vertical transmission. Furthermore, we highlight recent studies exploring the role of the maternal antibody response to SARS-CoV-2 during pregnancy and the passive transfer of maternal antibodies from mothers with COVID-19 to fetus.

Innate Lymphoid Cells in Human Pregnancy

Innate lymphoid cells (ILCs) are a new set of cells considered to be a part of the innate immune system. ILCs are classified into five subsets (according to their transcription factors and cytokine profile) as natural killer cells (NK cells), group 1 ILCs, group 2 ILCs, group 3 ILCs, and lymphoid tissue inducers (LTi). Functionally, these cells resemble the T helper population but lack the expression of recombinant genes, which is essential for the formation of T cell receptors. In this work, the authors address the distinction between peripheral and decidual NK cells, highlighting their diversity in ILC biology and its relevance to human pregnancy. ILCs are effector cells that are important in promoting immunity, inflammation, and tissue repair. Recent studies have directed their attention to ILC actions in pregnancy. Dysregulation or expansion of pro-inflammatory ILC populations as well as abnormal tolerogenic responses may directly interfere with pregnancy, ultimately resulting in pregnancy loss or adverse outcomes. In this review, we characterize these cells, considering recent findings and addressing knowledge gaps in perinatal medicine in the context of ILC biology. Moreover, we discuss the relevance of these cells not only to the process of immune tolerance, but also in disease.

Serum leukotriene B4 and hydroxyeicosatetraenoic acid in the prediction of pre-eclampsia

INTRODUCTION

Pre-eclampsia (PE) affects 2-8% of pregnancies worldwide. Despite identification of numerous possible biomarkers, accurate prediction and early diagnosis of PE remain challenging. We examined the potential of leukotriene B4 (LTB4) and 15-hydroxyeicosatetraenoic acid (15(S)-HETE) as biomarkers of PE by comparing serum levels at three gestational age (GA) groups between normotensive pregnancies and asymptomatic women who subsequently developed preterm or term-PE.

METHODS

This is a case-control study drawn from a prospective study of adverse pregnancy outcomes with serum samples collected at 19-24 weeks (n = 48), 30-34 weeks (n = 101) and 35-37 weeks (n = 54) GA. LTB4 and 15(S)-HETE levels were determined by ELISA. Serum level multiples of the median (MoM) were compared between normal and PE-pregnancies. Association between LTB4 and 15(S)-HETE and GA at delivery was investigated with Cox proportional-hazards models.

RESULTS

Serum LTB4 levels were lower in women of East-Asian ethnicity, higher in women with PE history, and increased with GA in normotensive pregnancies, but not in PE. LTB4 was elevated at 19-24 weeks in women who developed preterm-PE. There was a negative association between LTB4 MoM and interval between sampling and delivery with PE at 19-24 weeks only. Serum 15(S)-HETE levels were not influenced by GA at testing and were elevated in women of South-Asian ethnicity. Median 15(S)-HETE levels were unchanged in preterm and term-PE at any GA.

DISCUSSION

LTB4 was higher at 19-24 weeks in pregnancies that developed preterm-PE versus unaffected pregnancies, suggesting it is a potentially useful predictive marker of preterm PE in the second trimester.

A systematic review and meta-analysis of the correlation between maternal and neonatal iron status and haematologic indices

BACKGROUND

Iron deficiency (ID) is the leading single-nutrient deficiency in the world. Anaemia is a common outcome of ID that affects half of pregnancies worldwide with serious consequences for child development. Whether haematologic indices and biomarkers of iron status in pregnant women correlate with those of their neonates is unclear. This systematic review evaluated studies comparing haematologic and iron status indices in pregnant women and their newborns/neonates.

METHODS

We searched MEDLINE, EMBASE, CINAHL, and Web of Science from database inception until March 2020 for primary studies comparing haematologic and iron status indices between women and their newborns up to 48 h after birth. We summarized the results descriptively and calculated pooled correlation coefficients in mothers and newborns/neonates using the Schmidt-Hunter method. The protocol was registered at PROSPERO International Prospective Register of Systematic Reviews (Registration number: CRD42018093094).

FINDINGS

Sixty-five studies were included. Pooled correlation coefficients for biomarkers of iron status in mothers and newborns/neonates were 0.13 (ferritin), 0.42 (hepcidin), 0.30 (serum/plasma iron), 0.09 (transferrin), 0.20 (transferrin saturation), and 0.16 (total iron binding capacity). Pooled correlation coefficients for haematological indices in mothers and newborns/neonates were 0.15 (haemoglobin), 0.15 (haematocrit), 0.25 (mean cell/corpuscular haemoglobin), 0.22 (mean cell/corpuscular volume).

INTERPRETATION

Maternal biomarkers of iron and haematologic status correlate poorly with those in newborns/neonates. These results underscore a need for alternative approaches to estimate foetal/neonatal iron status and haematological indices.

FUNDING

MBO and SLB hold Canada Research Chairs, and grants from the Women and Children's Health Research Institute and Canadian Institutes of Health Research.

Innate Immune Responses to Acute Viral Infection During Pregnancy

Immunological adaptations in pregnancy allow maternal tolerance of the semi-allogeneic fetus but also increase maternal susceptibility to infection. At implantation, the endometrial stroma, glands, arteries and immune cells undergo anatomical and functional transformation to create the decidua, the specialized secretory endometrium of pregnancy. The maternal decidua and the invading fetal trophoblast constitute a dynamic junction that facilitates a complex immunological dialogue between the two. The decidual and peripheral immune systems together assume a pivotal role in regulating the critical balance between tolerance and defense against infection. Throughout pregnancy, this equilibrium is repeatedly subjected to microbial challenge. Acute viral infection in pregnancy is associated with a wide spectrum of adverse consequences for both mother and fetus. Vertical transmission from mother to fetus can cause developmental anomalies, growth restriction, preterm birth and stillbirth, while the mother is predisposed to heightened morbidity and maternal death. A rapid, effective response to invasive pathogens is therefore essential in order to avoid overwhelming maternal infection and consequent fetal compromise. This sentinel response is mediated by the innate immune system: a heritable, highly evolutionarily conserved system comprising physical barriers, antimicrobial peptides (AMP) and a variety of immune cells—principally neutrophils, macrophages, dendritic cells, and natural killer cells—which express pattern-receptors that detect invariant molecular signatures unique to pathogenic micro-organisms. Recognition of these signatures during acute infection triggers signaling cascades that enhance antimicrobial properties such as phagocytosis, secretion of pro-inflammatory cytokines and activation of the complement system. As well as coordinating the initial immune response, macrophages and dendritic cells present microbial antigens to lymphocytes, initiating and influencing the development of specific, long-lasting adaptive immunity. Despite extensive progress in unraveling the immunological adaptations of pregnancy, pregnant women remain particularly susceptible to certain acute viral infections and continue to experience mortality rates equivalent to those observed in pandemics several decades ago. Here, we focus specifically on the pregnancy-induced vulnerabilities in innate immunity that contribute to the disproportionately high maternal mortality observed in the following acute viral infections: Lassa fever, Ebola virus disease (EVD), dengue fever, hepatitis E, influenza, and novel coronavirus infections.

Challenges for the Newborn Immune Response to Respiratory Virus Infection and Vaccination

The initial months of life reflect an extremely challenging time for newborns as a naïve immune system is bombarded with a large array of pathogens, commensals, and other foreign entities. In many instances, the immune response of young infants is dampened or altered, resulting in increased susceptibility and disease following infection. This is the result of both qualitative and quantitative changes in the response of multiple cell types across the immune system. Here we provide a review of the challenges associated with the newborn response to respiratory viral pathogens as well as the hurdles and advances for vaccine-mediated protection.

Intrauterine administration of autologous hCG- activated peripheral blood mononuclear cells improves pregnancy outcomes in patients with recurrent implantation failure; A double-blind, randomized control trial study

We aimed to investigate the effect of intrauterine administration of autologous hCG-activated PBMCs in RIF women with low Th-17/Treg cell ratio. 248 women with a history of implantation failure volunteered to receive PBMC-therapy. After immunologic consultation and doing flow cytometry analysis, 100 women with at least three IVF/ET failure who had low Th-17/Treg ratio in comparison with healthy control were enrolled in this study. These 100 patients were randomly divided into two groups as PBMC receiving (n = 50) and controls (n = 50). Then PBMCs were obtained from patients and treated with hCG for 48 h. Afterward, PBMCs were administered into the uterine cavity of the patient in the study group, two days before ET. The concentration of inflammatory cytokines was examined in the supernatant of cultured PBMCs after 2, 24, and 48 h of incubation using the ELISA method. The frequency of Th-17, Treg, and the Th-17/Treg ratio was significantly lower in RIF women than the healthy controls (P < 0.0001). The secretion of inflammatory cytokines was significantly higher after 48 h compared to 2 and 24 h (P < 0.0001). The pregnancy and live birth rate were significantly increased in women undergoing the PBMC-therapy compared to control (PBS-injecting) group (P = 0.032 and P = 0.047, respectively). The miscarriage rate was considerably lower in PBMC-therapy group (P = 0.029). Our findings suggest that intrauterine administration of autologous in vitro hCG-activated PBMCs improves pregnancy outcomes in patients with at least three IVF/ET failures.

Relationships between objective sleep parameters and inflammatory biomarkers in pregnancy

We examined the relationships between sleep and inflammatory biomarkers during late pregnancy. Seventy-four women underwent an overnight sleep assessment by polysomnography. Blood samples were collected before bedtime and again within 1 h upon awakening to measure C-reactive protein (CRP), interleukin (IL)-6, and IL-6 soluble receptor. Sleep parameters included variables characterizing sleep architecture and sleep continuity. The participants were 32.2 (SD = 4.1) years old, and the average gestational age was 32.8 (3.5) weeks. Controlling for covariates, evening CRP was negatively associated with N3 sleep (β = -0.30, P = 0.010). N3 sleep was also negatively associated with morning CRP (β = -0.26, P = 0.036), with a higher percentage of N3 sleep associated with a lower level of morning CRP. Contrarily, there was a tendency for a positive association between stage N2 sleep and morning CRP (β = 0.23, P = 0.065). Stage N1 sleep was associated with morning IL-6 (β = 0.28, P = 0.021), with a higher percentage of N1 sleep associated with a higher morning IL-6. No significant associations were found between morning inflammatory biomarkers and sleep continuity parameters. In conclusion, increased light sleep was associated with increased inflammatory biomarkers, whereas more deep sleep was associated with decreased inflammatory biomarkers. These findings further support the interactions between sleep and the immune system during late pregnancy.

Major Variation in the Incidence of Appendicitis Before, During and After Pregnancy: A Population-Based Cohort Study

BACKGROUND

Previous studies indicate a low incidence of appendicitis in third-trimester pregnancy, suggesting a protecting effect of pregnancy. This large population-based cohort study analyzes the association of appendicitis with pregnancy in more detail. The aim of the study was to investigate the incidence of appendicitis and negative appendectomy before, during and after pregnancy.

METHODS

Cross-linking between two Swedish health registries provided data on appendectomy for all women in Sweden giving birth between 1973 and 2013. We analyzed the incidence rates (IR) of perforated and non-perforated appendicitis and negative appendectomy before, during and after pregnancy, and secular trends during the study period. Standardized incidence ratios (SIR) were estimated using age-, sex- and period-specific IR from the background population in Sweden.

RESULTS

Some 3,888,452 pregnancies resulted in birth during the study period. An appendectomy was registered for 27,575 women in the interval starting one year before and ending two years after pregnancy. The incidence of appendicitis varied substantially during and after pregnancy. SIR for perforated appendicitis was 0.47 (95% CI 0.38-0.59) in the third trimester, 3.89 (2.92-5.18) peripartum, 2.20 (1.89-2.55) in the puerperium and 1.27 (1.19-1.36) in the year postpartum. The pattern was similar for non-perforated appendicitis. Negative appendectomy decreased postpartum. Incidence rate of non-perforated appendicitis and negative appendectomy decreased for both pregnant and non-pregnant women during the study period.

CONCLUSIONS

The findings in this study suggest a protecting effect of pregnancy on the development of appendicitis, which is followed by a rebound effect after birth.

Human Chorionic Gonadotropin modulates CXCL10 Expression through Histone Methylation in human decidua

The process of implantation, trophoblast invasion and placentation demand continuous adaptation and modifications between the trophoblast (embryonic) and the decidua (maternal). Within the decidua, the maternal immune system undergoes continued changes, as the pregnancy progress, in terms of the cell population, phenotype and production of immune factors, cytokines and chemokines. Human chorionic gonadotropin (hCG) is one of the earliest hormones produced by the blastocyst and has potent immune modulatory effects, especially in relation to T cells. We hypothesized that trophoblast-derived hCG modulates the immune population present at the maternal fetal interface by modifying the cytokine profile produced by the stromal/decidual cells. Using in vitro models from decidual samples we demonstrate that hCG inhibits CXCL10 expression by inducing H3K27me3 histone methylation, which binds to Region 4 of the CXCL10 promoter, thereby suppressing its expression. hCG-induced histone methylation is mediated through EZH2, a functional member of the PRC2 complex. Regulation of CXCL10 expression has a major impact on the capacity of endometrial stromal cells to recruit CD8 cells. We demonstrate the existence of a cross talk between the placenta (hCG) and the decidua (CXCL10) in the control of immune cell recruitment. Alterations in this immune regulatory function, such as during infection, will have detrimental effects on the success of the pregnancy.

Medawar's Paradox and Immune Mechanisms of Fetomaternal Tolerance

Brazilian-born British biologist Dr. Peter Medawar played an integral role in developing the concepts of immunologic rejection and tolerance, which led to him receiving the Nobel Prize "for the discovery of acquired immunologic tolerance" and eventually made organ transplantation a reality. However, at the time of his early work in tolerance, a paradox to his theories was brought to his attention; how was pregnancy possible? Pregnancy resembles organ transplantation in that the fetus, possessing paternal antigens, is a semi-allogeneic graft that can survive without immunosuppression for 9 months. To answer this question, Medawar proposed three hypotheses of how a mother supports her fetus in utero, now known as "Medawar's Paradox." The mechanisms that govern fetomaternal tolerance are still incompletely understood but may provide critical insight into how to achieve immune tolerance in organ transplantation. Here, we review current understanding of the immune factors responsible for fetomaternal tolerance during pregnancy and discuss the potential implications for advances in transplantation science.

Sexual Dimorphism in Innate Immunity

Sexual dimorphisms account for differences in clinical manifestations or incidence of infectious or autoimmune diseases and malignancy between females and males. Females develop enhanced innate and adaptive immune responses than males and are less susceptible to many infections of bacterial, viral, parasitic, and fungal origin and malignancies but in contrast, they are more prone to develop autoimmune diseases. The higher susceptibility to infections in males is observed from birth to adulthood, suggesting that sex chromosomes and not sex hormones have a major role in sexual dimorphism in innate immunity. Sex-based regulation of immune responses ultimately contributes to age-related disease development and life expectancy. Differences between males and females have been described in the expression of pattern recognition receptors of the innate immune response and in the functional responses of phagocytes and antigen presenting cells. Different factors have been shown to account for the sex-based disparity in immune responses, including genetic factors and hormonal mediators, which contribute independently to dimorphism in the innate immune response. For instance, several genes encoding for innate immune molecules are located on the X chromosome. In addition, estrogen and/or testosterone have been reported to modulate the differentiation, maturation, lifespan, and effector functions of innate immune cells, including neutrophils, macrophages, natural killer cells, and dendritic cells. In this review, we will focus on differences between males and females in innate immunity, which represents the first line of defense against pathogens and plays a fundamental role in the activation, regulation, and orientation of the adaptive immune response.

Sepsis: Precision-Based Medicine for Pregnancy and the Puerperium

Sepsis contributes significantly to global morbidity and mortality, particularly in vulnerable populations. Pregnant and recently pregnant women are particularly prone to rapid progression to sepsis and septic shock, with 11% of maternal deaths worldwide being attributed to sepsis. The impact on the neonate is considerable, with 1 million neonatal deaths annually attributed to maternal infection or sepsis. Pregnancy specific physiological and immunological adaptations are likely to contribute to a greater impact of infection, but current approaches to the management of sepsis are based on those developed for the non-pregnant population. Pregnancy-specific strategies are required to optimise recognition and management of these patients. We review current knowledge of the physiology and immunology of pregnancy and propose areas of research, which may advance the development of pregnancy-specific diagnostic and therapeutic approaches to optimise the care of pregnant women and their babies.

Pregnancy-Related Immune Changes and Demyelinating Diseases of the Central Nervous System

Demyelinating diseases of the central nervous system comprise a heterogeneous group of autoimmune disorders characterized by myelin loss with relative sparing of axons occurring on a background of inflammation. Some of the most common demyelinating diseases are multiple sclerosis, acute disseminated encephalomyelitis, and neuromyelitis optica spectrum disorders. Besides showing clinical, radiological, and histopathological features that complicate their diagnosis, demyelinating diseases often involve different immunological processes that produce distinct inflammatory patterns. Evidence of demyelination diseases derives mostly from animal studies of experimental autoimmune encephalomyelitis (EAE), a model that relies on direct antibody–antigen interactions induced by encephalitogenic T cells. Pregnancy is characterized by non-self-recognition, immunomodulatory changes and an altered Th1/Th2 balance, generally considered a Th2-type immunological state that protects the mother from infections. During pregnancy, the immune response of patients with autoimmune disease complicated with pregnancy is different. Immune tolerance in pregnancy may affect the course of some diseases, which may reach remission or be exacerbated. In this review, we summarize current knowledge on the immune status during pregnancy and discuss the relationship between pregnancy-related immune changes and demyelinating diseases of the central nervous system.

Proinflammatory profile of neonatal monocytes induced by microbial ligands is downmodulated by histamine

Although the neonatal period is characterized by relative immunological immaturity, an inflammatory response due to Toll-like receptor (TLR) activation is observed. Histamine may be one of the factors playing a role in restraining inflammation during the early stages of life. Therefore, we evaluated the responsiveness of human cord blood cells to TLR4 agonists and the immunomodulatory function of histamine in the inflammatory response. Compared with adults, mononuclear cells (MNCs) from newborns (NBs) exhibit impaired production of IFN-γ-inducible chemokines, such as CXCL10 and CXCL9, upon lipopolysaccharide (LPS) stimulation. Notably, LPS induced a 5-fold increase in CCL2 secretion in NBs. Evaluation of the effect of histamine on LPS-induced CCL2 secretion showed an inhibitory effect in the majority of adults, whereas this effect was detectable in all NBs. Histamine receptor (HR) blockage revealed partial involvement of H1R, H2R and H4R in LPS-induced CCL2 inhibition in MNCs from both NBs and adults. As monocytes are the main type of mononuclear cell that produces CCL2, we evaluated genes related to TLR signaling upon LPS stimulation. Monocytes from NBs showed up-regulation of genes associated with JAK/STAT/NF-κB and IFN signaling. Some differentially expressed genes encoding proinflammatory factors were preferentially detected in LPS-activated monocytes from NBs, and markedly down-regulated by histamine. The immunomodulatory role of histamine on CCL2 and CXCL8 was detected at the transcript and protein levels. Our findings show that NBs have enhanced CCL2 responsiveness to LPS, and that histamine acts in immune homeostasis during the neonatal period to counterbalance the robustness of TLR stimulation.

The Pregnancy Pickle: Evolved Immune Compensation Due to Pregnancy Underlies Sex Differences in Human Diseases

We hypothesize that, ancestrally, sex-specific immune modulation evolved to facilitate survival of the pregnant person in the presence of an invasive placenta and an immunologically challenging pregnancy - an idea we term the 'pregnancy compensation hypothesis' (PCH). Further, we propose that sex differences in immune function are mediated, at least in part, by the evolution of gene content and dosage on the sex chromosomes, and are regulated by reproductive hormones. Finally, we propose that changes in reproductive ecology in industrialized environments exacerbate these evolved sex differences, resulting in the increasing risk of autoimmune disease observed in females, and a counteracting reduction in diseases such as cancer that can be combated by heightened immune surveillance. The PCH generates a series of expectations that can be tested empirically and that may help to identify the mechanisms underlying sex differences in modern human diseases.

Progesterone decreases gut permeability through upregulating occludin expression in primary human gut tissues and Caco-2 cells

Progesterone plays a protective role in preventing inflammation and preterm delivery during pregnancy. However, the mechanism involved is unknown. Microbial product translocation from a permeable mucosa is demonstrated as a driver of inflammation. To study the mechanism of the protective role of progesterone during pregnancy, we investigated the effect of physiologic concentrations of progesterone on tight junction protein occludin expression and human gut permeability in vitro and systemic microbial translocation in pregnant women in vivo. Plasma bacterial lipopolysaccharide (LPS), a representative marker of in vivo systemic microbial translocation was measured. We found that plasma LPS levels were significantly decreased during 24 to 28 weeks of gestation compared to 8 to 12 weeks of gestation. Moreover, plasma LPS levels were negatively correlated with plasma progesterone levels but positively correlated with plasma tumor necrosis factor-alpha (TNF-α) levels at 8 to 12 weeks of gestation but not at 24 to 28 weeks of gestation. Progesterone treatment increased intestinal trans-epithelial electrical resistance (TEER) in primary human colon tissues and Caco-2 cells in vitro through upregulating tight junction protein occludin expression. Furthermore, progesterone exhibited an inhibitory effect on nuclear factor kappa B (NF-κB) activation following LPS stimulation in Caco-2 cells. These results reveal a novel mechanism that progesterone may play an important role in decreasing mucosal permeability, systemic microbial translocation, and inflammation during pregnancy.

Why Should We Advocate Maternal Immunization?

Maternal vaccination provides a method for protecting the pregnant woman, fetus and neonate during a period when there is increased susceptibility to infectious diseases. A dynamic state of immune tolerance during pregnancy and the need to develop adaptive memory to a new foreign antigen-rich environment lead to windows of vulnerability to infection for the mother and neonate, respectively. Passive transfer of humoral immunity through the placenta and breast milk from the mother can bridge the gap in immunity for the neonate. Studies on boosting this natural process of antibody transfer have led to the recommendation for administering inactivated influenza, diphtheria, tetanus toxoid and acellular pertussis vaccines during pregnancy. Several new maternal vaccine candidates are on the horizon.

Fine particulate matter alters the microecology of the murine respiratory tract

Fine particulate matter is a global challenge to human health. We investigated the effects and potential mechanisms of fine particulate matter on respiratory tract microecology in a lung injury mouse model. BALB/c mice were randomized into exposed and control groups. We found that the levels of soluble tumor necrosis factor receptor I was increased following the PM2.5 exposure. 16S rRNA sequencing of respiratory tract lavage fluid confirmed that the composition of the respiratory tract microecology was altered by the exposure. Lactobacillus was the most abundant of bacterial species present. Collectively, these results establish a link between exposure to fine particulate matter and alterations to the respiratory tract microecology. Elucidation of the underlying mechanisms may lead to treatment strategies in lung injury.

Uveitis causes according to immune status of patients

Purpose

The advances in medicine have led to an increased number of people living with some form of immunodeficiency. Most ocular infections in immunocompromised patients may lead to irreversible blindness. We identify the causes of uveitis in immunocompetent and immunocompromised patients.

Methods

A retrospective cohort study of 1354 consecutive patients. All patients underwent a standard work‐up for uveitis.

Results

An immunocompromised state was identified in 171/1354 patients (13%), of whom 40 had Human immunodeficiency virus (HIV) infection, 52 received immunosuppressive medications, 28 had concurrent malignant disorder and 20 had other causes for their immunosuppression. In addition, 93/1354 patients (7%) had diabetes mellitus (DM). The prevalence of intraocular infections was much higher in immunocompromised patients than in immunocompetent patients and DM (p < 0.001). Causes of uveitis differed between the diverse immunocompromised groups. The non‐HIV immunocompromised patients showed primarily intraocular herpes simplex and varicella zoster virus infections, whilst HIV‐positive patients exhibited frequently cytomegalovirus (CMV) retinitis and syphilis. Patients with generalized malignancies were characterized by a lower prevalence of infections and higher prevalence of sarcoidosis. Patients with DM typically showed sarcoidosis and bacterial intraocular infections. The percentage of undetermined uveitis diagnoses was markedly lower in immunosuppressed patients (p < 0.001).

Conclusion

In immunocompromised patients with uveitis, infections were diagnosed in 46% of cases in contrast to 12% in the immunocompetent patients. The causes of uveitis differed among the various types of immunosuppression. Immunocompromised patients with uveitis require a rapid assessment for the most expected infections.

The association between selected mid-trimester amniotic fluid candidate proteins and spontaneous preterm delivery

Objective: The aim of this study was to explore inflammatory response and identify early potential biomarkers in mid-trimester amniotic fluid associated with subsequent spontaneous preterm delivery (PTD).Methods: A cohort study was performed at Sahlgrenska University Hospital/Östra, Gothenburg, Sweden, between 2008 and 2010. Amniotic fluid was collected from consecutive women undergoing mid-trimester transabdominal genetic amniocentesis at 14-19 gestational weeks. Clinical data and delivery outcome variables were obtained from medical records. The analysis included 19 women with spontaneous PTD and 118 women who delivered at term. A panel of 26 candidate proteins was analyzed using Luminex xMAP technology. Candidate protein concentrations were analyzed with ANCOVA and adjusted for plate effects.Results: The median gestational age at delivery was 35 + 3 weeks in women with spontaneous PTD and 40 + 0 weeks in women who delivered at term. Nominally significantly lower amniotic fluid levels of adiponectin (PTD: median 130,695 pg/mL (IQR 71,852-199,414) vs term: median 185,329 pg/mL (IQR (135,815-290,532)), granulocyte-macrophage colony stimulating factor (PTD: median 137 pg/mL (IQR 74-156) vs term: median 176 pg/mL (IQR 111-262)), and macrophage migration inhibitory factor (PTD: median 3025 pg/mL (IQR 1885-3891) vs term: median 3400 pg/mL (IQR 2181-5231)) were observed in the spontaneous PTD group, compared with the term delivery group, after adjusting for plate effects. No significant differences remained after Bonferroni correction for multiple comparisons.Conclusions: Our results are important in the process of determining the etiology behind spontaneous PTD but due to the non-significance after Bonferroni correction, the results should be interpreted with caution. Further analyses of larger sample size will be required to determine whether these results are cogent and to examine whether microbial invasion of the amniotic cavity or intra-amniotic inflammation occurs in asymptomatic women in the mid-trimester with subsequent spontaneous PTD.

Patterns of Systemic and Cervicovaginal Fluid Inflammatory Cytokines throughout Pregnancy

OBJECTIVE

 This study describes the normal variations in serum and cervicovaginal fluid (CVF) cytokine levels throughout pregnancy.

STUDY DESIGN

 This multicenter, prospective study examined trimester-specific maternal serum and CVF cytokines (interleukin [IL]-1α, IL-1β, IL-6, IL-8, IL-10, tumor necrosis factor-α, and C-reactive protein [CRP]). A two-factor linear mixed modeling approach compared cytokine distribution, while pairwise comparisons evaluated differences over time.

RESULTS

 Trimester-specific serum cytokine data were available for 288, 243, and 221 patients, whereas CVF cytokine data were available for 273, 229, and 198 patients. CVF had significantly higher concentrations of IL-1α, IL-1β, IL-6, IL-8, and matrix metalloproteinase-8 (p < 0.001), irrespective of the trimester. At all time points, IL-10 and CRP concentrations were higher in serum than CVF (p < 0.001). Serum IL-10 increased significantly throughout pregnancy (p < 0.001).

CONCLUSION

 Differences in cytokine distribution across different biological fluids are evident throughout pregnancy. These findings provide a framework for examining patterns of changes in cytokines throughout pregnancy.

Pregnancy-associated breast cancer: the risky status quo and new concepts of predictive medicine

The paper is motivated by severe concerns regarding currently applied care of the pregnancy-associated breast cancer (PABC) characterised by particularly poor outcomes of the disease. Psychological and ethical aspects play a crucial role in PABC: the highest priority not to damage the foetus significantly complicates any treatment generally, and it is quite usual that patients disclaim undergoing any breast cancer treatment during pregnancy. Although, due to global demographic trends, PABC is far from appearing rarely now, severe societal and economic consequences of the disease are still neglected by currently applied reactive medical approach. These actualities require creating new strategies which should be better adapted to the needs of the society at large by advancing the PABC care based on predictive diagnostic approaches specifically in premenopausal women, innovative screening programmes focused on young female populations, targeted prevention in high-risk groups, and optimised treatment concepts. The article summarises the facts and provides recommendations to advance the field-related research and medical services specifically dedicated to the PABC care.