Maternal SARS-CoV-2 infection in pregnancy disrupts gene expression in Hofbauer cells with limited impact on cytotrophoblasts.

BACKGROUND: Hofbauer cells (HBCs) and cytotrophoblasts (CTBs) are major cell populations in placenta. The indirect impact of maternal SARS-CoV-2 disease on these cells that are not directly infected has not been extensively studied. Herein, we profiled gene expression in HBCs and CTBs isolated from placentae of recovered pregnant subjects infected with SARS-CoV-2 during all trimesters of pregnancy, placentae from subjects with active infection, SARS-CoV-2 vaccinated subjects, and those who were unexposed to the virus. METHODS: Placentae were collected within 4 h post-delivery and membrane-free tissues were enzymatically digested for the isolation of HBCs and CTBs. RNA extracted from HBCs and CTBs were sequenced using 150bp paired-end reads. Differentially expressed genes (DEGs) were identified by DESeq2 package in R and enriched in GO Biological Processes, KEGG Pathway, Reactome Gene Sets, Hallmark Gene Sets, and Canonical Pathways. Protein-protein interactions among the DEGs were modelled using STRING and BioGrid. RESULTS: Pregnant subjects (n = 30) were recruited and categorized into six groups: infected with SARS-CoV-2 in i) the first (1T, n = 4), ii) second (2T, n = 5), iii) third (3T, n = 5) trimester, iv) tested positive at delivery (Delivery, n = 5), v) never infected (Control, n = 6), and vi) fully mRNA-vaccinated by delivery (Vaccinated, n = 5). Compared to the Control group, gene expression analysis showed that HBCs from infected subjects had significantly altered gene expression profiles, with the 2T group having the highest number of DEGs (1,696), followed by 3T and 1T groups (1,656 and 958 DEGs, respectively). These DEGs were enriched for pathways involved in immune regulation for host defense, including production of cytokines, chemokines, antimicrobial proteins, ribosomal assembly, neutrophil degranulation inflammation, morphogenesis, and cell migration/adhesion. Protein-protein interaction analysis mapped these DEGs with oxidative phosphorylation, translation, extracellular matrix organization, and type I interferon signaling. Only 95, 23, and 8 DEGs were identified in CTBs of 1T, 2T, and 3T groups, respectively. Similarly, 11 and 3 DEGs were identified in CTBs and HBCs of vaccinated subjects, respectively. Reassuringly, mRNA vaccination did not induce an inflammatory response in placental cells. CONCLUSIONS: Our studies demonstrate a significant impact of indirect SARS-CoV-2 infection on gene expression of inner mesenchymal HBCs, with limited effect on lining CTB cells isolated from pregnant subjects infected and recovered from SARS-CoV-2. The pathways associated with these DEGs identify potential targets for therapeutic intervention.

Vertical Transmission of SARS-CoV-2-Specific Antibodies and Cytokine Profiles in Pregnancy.

Despite intensive characterization of immune responses after COVID-19 infection and vaccination, research examining protective correlates of vertical transmission in pregnancy are limited. Herein, we profiled humoral and cellular characteristics in pregnant women infected or vaccinated at different trimesters and in their corresponding newborns. We noted a significant correlation between spike S1-specific IgG antibody and its RBD-ACE2 blocking activity (receptor-binding domain-human angiotensin-converting enzyme 2) in maternal and cord plasma (P < .001, R > 0.90). Blocking activity of spike S1-specific IgG was significantly higher in pregnant women infected during the third trimester than the first and second trimesters. Elevated levels of 28 cytokines/chemokines, mainly proinflammatory, were noted in maternal plasma with infection at delivery, while cord plasma with maternal infection 2 weeks before delivery exhibited the emergence of anti-inflammatory cytokines. Our data support vertical transmission of protective SARS-CoV-2-specific antibodies. This vertical antibody transmission and the presence of anti-inflammatory cytokines in cord blood may offset adverse outcomes of inflammation in exposed newborns.

Prevention of the Vertical Transmission of HIV; A Recap of the Journey so Far.

In 1989, one in four (25%) infants born to women living with HIV were infected; by the age of 2 years, there was 25% mortality among them due to HIV. These and other pieces of data prompted the development of interventions to offset vertical transmission, including the landmark Pediatric AIDS Clinical Trial Group Study (PACTG 076) in 1994. This study reported a 67.5% reduction in perinatal HIV transmission with prophylactic antenatal, intrapartum, and postnatal zidovudine. Numerous studies since then have provided compelling evidence to further optimize interventions, such that annual transmission rates of 0% are now reported by many health departments in the US and elimination has been validated in several countries around the world. Despite this success, the elimination of HIV's vertical transmission on the global scale remains a work in progress, limited by socioeconomic factors such as the prohibitive cost of antiretrovirals. Here, we review some of the key trials underpinning the development of guidelines in the US as well as globally, and discuss the evidence through a historic lens.

A Systematic Review to Evaluate a Possible Association Between Congenital Toxoplasmosis and Preterm Labor.

BACKGROUND: Congenital toxoplasmosis (CT) is a widespread infection in several countries, and it is defined as an infection of a fetus, newborn, or infant under 1 year of age. Moreover, it represents a thread to pregnant women globally. The objective of our study is to evaluate a potential association between prematurity and CT and whether intrauterine transmission impacts gestational length during pregnancy. METHODS: PubMed, Cochrane Library and Google Scholar databases were searched from 1950 to 2019. Case-control studies, retrospective, and prospective cohort studies were eligible. Seven studies were included from a total of 314. The Newcastle-Ottawa scale was used to establish the quality of the articles included. RESULTS: Based on our review, an association between CT and preterm labor was not established, which may reflect heterogeneity in screening, treatments administered, and differing reported incidences of CT across continents over 69 years. A multicenter prospective cohort study powered to investigate a potential association is indicated. CONCLUSION: Further studies are needed including multicenter prospective cohort studies powered to investigate key clinical associations such as vertical transmission and preterm birth.

Host-Viral Interactions at the Maternal-Fetal Interface. What We Know and What We Need to Know.

In humans, the hemochorial placenta is a unique temporary organ that forms during pregnancy to support fetal development, gaseous exchange, delivery of nutrition, removal of waste products, and provides immune protection, while maintaining tolerance to the HLA-haploidentical fetus. In this review, we characterize decidual and placental immunity during maternal viral (co)-infection with HIV-1, human cytomegalovirus (HCMV), and Zika virus. We discuss placental immunology, clinical presentation, and epidemiology, before characterizing host susceptibility and cellular tropism, and how the three viruses gain access into specific placental target cells. We describe current knowledge on host-viral interactions with decidual and stromal human placental macrophages or Hofbauer cells, trophoblasts including extra villous trophoblasts, T cells, and decidual natural killer (dNK) cells. These clinically significant viral infections elicit both innate and adaptive immune responses to control replication. However, the three viruses either during mono- or co-infection (HIV-1 and HCMV) escape detection to initiate placental inflammation associated with viral transmission to the developing fetus. Aside from congenital or perinatal infection, other adverse pregnancy outcomes include preterm labor and spontaneous abortion. In addition, maternal HIV-1 and HCMV co-infection are associated with impaired fetal and infant immunity in postnatal life and poor clinical outcomes during childhood in exposed infants, even in the absence of vertical transmission of HIV-1. Given the rapidly expanding numbers of HIV-1-exposed uninfected infants and children globally, further research is urgently needed on neonatal immune programming during maternal mono-and co-infection. This review therefore includes sections on current knowledge gaps that may prompt future research directions. These gaps reflect an emerging but poorly characterized field. Their significance and potential investigation is underscored by the fact that although viral infections result in adverse consequences in both mother and developing fetus/newborn, antiviral and immunomodulatory therapies can improve clinical outcomes in the dyad.

Preventing the voltage drop: keeping practice-based research network (PBRN) practices engaged in studies.

INTRODUCTION: Practice-based research continues to evolve and has become a major methodology for many pragmatic studies. While early practice-based network projects were usually short term, current studies often introduce or compare practice innovations that require long-term evaluation. That change requires that practice sites remain engaged in research work for up to 5 years, a time that can allow for a significant "voltage drop," or decline in active participation. METHODS: Over the past 15 years we have developed and adapted several strategies to facilitate and encourage the continued active engagement of practices in practice-based research network studies of up to 5 years' duration. The concepts, details, evaluation, and results (when available) of the strategies are described. RESULTS: Eight strategies that enhance practice sites' attention to enrollment, data collection and continued use of the implemented practice change are described. CONCLUSION: The loss of momentum, or "voltage drop," that happens in longer-term practice-based research network studies can be addressed using multiple strategies.

Protocol for the asthma tools study: a pragmatic practice-based research network trial.

BACKGROUND: Asthma is common among children, adolescents, and adults. However, management of asthma often fails to follow evidence-based guidelines. Control assessments have been developed, validated against expert opinion, and disseminated. However, in primary care, assessment of control is only one step in asthma management. To facilitate integration of the evidence-based guidelines into practice, tools should also guide the next steps in care. The Asthma APGAR tools do just that, incorporating a control assessment as well as assessment of the most common reasons for inadequate and poor control. The Asthma APGAR tool is also linked to a care algorithm based on the 2007 National Heart, Lung, and Blood Institute asthma guidelines. The objective of this study is to assess the impact of implementation of the Asthma APGAR on patient asthma outcomes in primary care practices. METHODS: A total of 1400 patients aged 5-60 years with physician-diagnosed asthma are enrolled in 20 practice-based research network (PBRN) practices randomized to intervention or usual care. The primary outcomes are changes in patient self-reported asthma control, asthma-related quality of life, and rates of exacerbations documented in medical records over the 18-24 months of enrollment. Process measures related to implementation of the Asthma APGAR system into daily care will also be assessed using review of medical records. Qualitative assessments will be used to explore barriers to and facilitators for integrating the Asthma APGAR tools into daily practice in primary care. DISCUSSION: Data from this pivotal pragmatic study are intended to demonstrate the importance of linking assessment of asthma and management tools to improve asthma-related patient outcomes. The study is an effectiveness trial done in real-world PBRN practices using patient-oriented outcome measures, making it generalizable to the largest possible group of asthma care providers and primary care clinics.