Inhibition of progenitor dendritic cell maturation by plasma from patients with peripartum cardiomyopathy: role in pregnancy-associated heart disease

Dendritic Cells and the Establishment of Fetomaternal Tolerance for Successful Human Pregnancy

Pregnancy is a remarkable event where the semi-allogeneic fetus develops in the mother's uterus, despite genetic and immunological differences. The antigen handling and processing at the maternal-fetal interface during pregnancy appear to be crucial for the adaptation of the maternal immune system and for tolerance to the developing fetus and placenta. Maternal antigen-presenting cells (APCs), such as macrophages (Mφs) and dendritic cells (DCs), are present at the maternal-fetal interface throughout pregnancy and are believed to play a crucial role in this process. Despite numerous studies focusing on the significance of Mφs, there is limited knowledge regarding the contribution of DCs in fetomaternal tolerance during pregnancy, making it a relatively new and growing field of research. This review focuses on how the behavior of DCs at the maternal-fetal interface adapts to pregnancy's unique demands. Moreover, it discusses how DCs interact with other cells in the decidual leukocyte network to regulate uterine and placental homeostasis and the local maternal immune responses to the fetus. The review particularly examines the different cell lineages of DCs with specific surface markers, which have not been critically reviewed in previous publications. Additionally, it emphasizes the impact that even minor disruptions in DC functions can have on pregnancy-related complications and proposes further research into the potential therapeutic benefits of targeting DCs to manage these complications.

Metabolic Reprogramming of Immune Cells at the Maternal-Fetal Interface and the Development of Techniques for Immunometabolism

Immunity and metabolism are interdependent and coordinated, which are the core mechanisms for the body to maintain homeostasis. In tumor immunology research, immunometabolism has been a research hotspot and has achieved groundbreaking changes in recent years. However, in the field of maternal-fetal medicine, research on immunometabolism is still lagging. Reports directly investigating the roles of immunometabolism in the endometrial microenvironment and regulation of maternal-fetal immune tolerance are relatively few. This review highlights the leading techniques used to study immunometabolism and their development, the immune cells at the maternal-fetal interface and their metabolic features required for the implementation of their functions, explores the interaction between immunometabolism and pregnancy regulation based on little evidence and clues, and attempts to propose some new research directions and perspectives.

Systematic review and meta-analysis of prolactin and iron deficiency in peripartum cardiomyopathy

OBJECTIVES

We conducted a systematic review and meta-analysis of studies that compared levels of molecular biomarkers in women with peripartum cardiomyopathy (PPCM) to those in healthy pregnant and postpartum women to: (1) assess the evidence for prolactin (PRL) metabolism in PPCM, (2) ascertain the evidence for biomarkers of iron deficiency in PPCM, (3) identify other biomarkers associated with PPCM.

METHODS

We searched Medline, Embase, Cumulated Index to Nursing and Allied Health Literature (CINAHL) and the Global Health Library from inception without language restriction for studies that compared biomarkers levels in PPCM cases to healthy controls. Pooled standardised mean difference (SMD) was generated using a random effects model for the difference in levels of biomarkers.

RESULTS

Two studies assessed the association of PRL with PPCM, and reported that PPCM cases have higher levels of total PRL. No studies investigated iron metabolism in PPCM. Other biomarkers associated with PPCM included serum levels of natriuretic peptides (SMD=3.77, 95% CI 0.71 to 6.82), albumin (SMD=-0.67, 95% CI -1.01 to -0.32), C-reactive protein (SMD=1.67, 95% CI 0.22 to 3.12), selenium (SMD=-0.73, 95% CI -1.58 to 0.12), cardiac troponins (SMD=1.06, 95% CI 0.33 to 1.80), creatinine (SMD=0.51, 95% CI 0.33 to 0.69), white bloodcells (SMD=0.44, 95 % CI 0.07 to 0.82), haemoglobin (SMD=-0.45, 95% CI -0.64 to-0.26).

CONCLUSIONS

More robust molecular studies are needed to explore the association between prolactin and PPCM in human subjects and to determine the extent to which iron deficiency (with or without anaemia) contributes to the risk of PPCM.

Dendritic cells in pregnancy and pregnancy-associated diseases

Dendritic cells (DCs) play a critical immuno-modulating role in pregnancy, which requires the maternal immune system to tolerate semiallogeneic fetus and at the same time to maintain adequate defense against pathogens. DCs interact closely with other immune components such as T cells, natural killer cells and macrophages, as well as the endocrine system to keep a pregnancy-friendly environment. Aberrant DC activities have been related to various pregnancy-associated diseases such as recurrent spontaneous abortion, preterm birth, pre-eclampsia, peripartum cardiomyopathy and infectious pregnancy complications. These findings make DCs an attractive candidate for prevention or therapy on the pregnancy-associated diseases. Here, we review recent findings that provide new insights into the roles of DCs in pregnancy and the related diseases. We also discuss the medical potentials to manipulate DCs in clinics. Whereas this is an emerging area with much work remaining, we anticipate that a better understanding of the role of DCs in maternal-fetal immunotolerance and a therapeutic manipulation of DCs will help women suffering from the pregnancy-associated diseases.

Peripartum Cardiomyopathy: an Update

Purpose of Review

Peripartum cardiomyopathy (PPCM) is an idiopathic disorder defined as heart failure occurring in women during the last month of pregnancy and up to 5 months postpartum. In this review, we outline recent reports about the disease pathogenesis and management and highlight the use of diagnosis and prognosis biomarkers.

Recent Findings

Novel data strengthen the implication of endothelial function in PPCM pathogenesis. The first international registry showed that patient presentations were similar globally, with heterogeneity in patient management and outcome.

Summary

Despite large improvement in patient management and treatment, there is still a sub-group of women who die from PPCM or who will not recover their cardiac function. Remarkable advances in the comprehension of disease incidence, pathogenesis, and prognosis could be determined with multi-center and international registries.

Clinical Trials

ClinicalTrials.gov Identifier: NCT02590601

Earlier detection can help avoid many serious complications of peripartum cardiomyopathy

Peripartum cardiomyopathy (PPCM) has a remarkable potential for recovery. It may be within our capability to help almost all women with PPCM not only to survive, but also to completely recover heart function. Time-of-diagnosis left ventricular ejection fraction (LVEF) ≥0.35 is associated with better survival rates and higher full recovery rates. Increased mortality, chronic cardiomyopathy, thromboembolic complications and serious ventricular tachyarrhythmias are associated with diagnostic LVEF <0.30. Delays in diagnosis may result in lower LVEF at diagnosis and subsequent lower recovery rates. Greater awareness of the possibility of heart failure developing in previously healthy young women, with no history of heart disease, will contribute to earlier diagnosis, with potentially better preserved heart function. Women of African descent may be at higher risk for poorer outcomes. Recent investigations suggest newer biomarkers may help with earlier detection of PPCM.

Inflammatory markers and cytokines in peripartum cardiomyopathy: a delicate balance

Acute peripartum cardiomyopathy, a unique form of heart failure with onset in the last phase of pregnancy or shortly postpartum, has demonstrated evidence of an inflammatory process characterized by cytokine imbalance. Cytokines serve as inducers of repair mechanisms and promoters of both inflammatory and anti-inflammatory immune responses. Elevated plasma C-reactive protein, a marker of an inflammatory process, is co-expressed in the heart with the pro-inflammatory cytokine, TNF-alpha. Both pro-inflammatory and anti-inflammatory cytokines are involved in an intricate balance in response to injury to the heart. This article discusses potential and identified imbalances in levels of cytokines in peripartum cardiomyopathy that have led to clinical trials aimed at the modulation of select number of cytokines, some of which have been shown to have significant clinical benefit. Continuing investigation in this area is important since restoration of critical cytokine balance may be an area that holds promise for therapy. At the same time, one must be cautious in the timing of any intervention that alters cytokine balance.

Personal commentary: monitoring subsequent pregnancy in recovered peripartum cardiomyopathy mothers

Peripartum cardiomyopathy (PPCM) is defined as the first appearance of systolic heart failure in a previously healthy woman during the last month of pregnancy or up to 6 months postpartum. Both planned and unplanned pregnancies may occur in recovered and non-recovered PPCM mothers, requiring careful counseling and management strategies. Previous studies indicate that relapse of heart failure in post-PPCM pregnancies is always a possibility, even in recovered PPCM mothers. The risk of relapse is high when the left ventricular ejection fraction is less than 0.50, and should be considered a relative contraindication to subsequent pregnancy. There are not yet established protocols for monitoring subsequent pregnancies in those who once had PPCM, and few medical articles with guidelines. This personal commentary contains parameters that have been found useful to contribute to safer monitoring with improved outcomes.

Peripartum cardiomyopathy: recent insights in its pathophysiology

Peripartum/Postpartum cardiomyopathy (PPCM) is a serious, potentially life-threatening heart disease of uncertain etiology in previously healthy women. Previous clinical and experimental data have identified inflammation, autoimmune processes, apoptosis, and impaired cardiac (systemic) microvasculature as typical features in the pathophysiology of PPCM. However, recent data have shown that unbalanced peri/postpartum oxidative stress is linked to proteolytic cleavage of the nursing hormone prolactin into a potent antiangiogenic, proapoptotic, and pro-inflammatory factor. These observations strongly suggest that prolactin cleavage can operate as a specific pathomechanism for the development of PPCM. Consistent with these findings, inhibition of prolactin secretion by bromocriptine, a dopamine D2 receptor agonist, prevented the development of PPCM in an animal model of PPCM, and first clinical experience are promising in this respect. Thus, inhibition of prolactin release may represent a novel specific therapeutic approach to either prevent or treat patients with acute PPCM. In this review, we are highlighting the current knowledge on risk factors, potential pathomechanisms, and treatment options for PPCM.

Fetal cord blood mononuclear cells that are collected at term from HIV-1 infected women harbor transcriptionally active integrated proviral DNA

OBJECTIVE

The purpose of this study was to determine levels of intrauterine infection and transcriptional activity in cord blood mononuclear cells that were collected at term from fetuses who were born to women who were infected with human immunodeficiency virus (HIV) and who received highly active antiretroviral therapy (HAART).

STUDY DESIGN

RNA and DNA were isolated from maternal placental tissues and fetal cord blood specimens that were obtained at term from pregnant women who were infected with HIV and who received HAART. Levels of integrated HIV provirus and messenger RNA transcripts were determined by real-time polymerase chain reaction.

RESULTS

Detectable levels of transcriptionally active integrated provirus were present in approximately 27% of cord blood samples (n = 22) that were collected from fetuses who born to HIV-positive mothers who received HAART. Levels of HIV-p24 antigen in cultures that were detected in randomly selected cord blood samples confirmed the presence of inducible infectious virus.

CONCLUSION

These findings suggest that some fetuses from HIV-infected mothers who receive HAART and who may be HIV-negative infants after delivery can harbor circulating leukocytes that are infected productively by intrauterine transmission of HIV.