Siglec-1 Macrophages and the Contribution of IFN to the Development of Autoimmune Congenital Heart Block

Modern Management of Pregnancy in Systemic Lupus Erythematosus: From Prenatal Counseling to Postpartum Support

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease that predominantly affects women of childbearing age. Pregnancy in SLE patients poses unique challenges due to the potential impact on maternal and fetal outcomes. We provide an overview of the management of SLE during pregnancy, including preconception risk stratification and counseling, treatment, and disease activity monitoring. These assessments are critical to minimize maternal and fetal adverse events in pregnant patients with SLE. Disease flares, preeclampsia, antiphospholipid syndrome complications, and maternal mortality are the major risks for a woman with SLE during gestation. Timely treatment of SLE relapse, differentiation of preeclampsia from lupus nephritis, and tailored management for antiphospholipid syndrome are essential for a successful pregnancy. Fetal outcomes include neonatal lupus (NL), preterm birth, cesarean delivery, fetal growth restriction (FGR), and small-for-gestational-age (SGA) infants. We focused on NL, linked to maternal anti-Ro/SS-A and anti-La/SS-B antibodies, which can lead to various manifestations, particularly cardiac abnormalities, in newborns. While there is a common consensus regarding the preventive effect of hydroxychloroquine, the role of echocardiographic monitoring and fluorinated steroid treatment is still debated. Finally, close postpartum monitoring and counseling for subsequent pregnancies are crucial aspects of care.

Molecular Mechanisms of Fetal and Neonatal Lupus: A Narrative Review of an Autoimmune Disease Transferal across the Placenta

This study, conducted by searching keywords such as "maternal lupus", "neonatal lupus", and "congenital heart block" in databases including PubMed and Scopus, provides a detailed narrative review on fetal and neonatal lupus. Autoantibodies like anti-Ro/SSA and anti-La/SSB may cross the placenta and cause complications in neonates, such as congenital heart block (CHB). Management options involve hydroxychloroquine, which is able to counteract some of the adverse events, although the drug needs to be used carefully because of its impact on the QTc interval. Advanced pacing strategies for neonates with CHB, especially in severe forms like hydrops, are also assessed. This review emphasizes the need for interdisciplinary care by rheumatologists, obstetricians, and pediatricians in order to achieve the best maternal and neonatal health in lupus pregnancies. This multidisciplinary approach seeks to improve the outcomes and management of the disease, decreasing the burden on mothers and their infants.

Monitoring of Women with Anti-Ro/SSA and Anti-La/SSB Antibodies in Germany-Status Quo and Intensified Monitoring Concepts

Background: The fetuses of pregnant women affected by anti-Ro/anti-La antibodies are at risk of developing complete atrioventricular heart block (CAVB) and other potentially life-threatening cardiac affections. CAVB can develop in less than 24 h. Treatment with anti-inflammatory drugs and immunoglobulins (IVIG) can restore the normal rhythm if applied in the transition period. Routine weekly echocardiography, as often recommended, will rarely detect emergent AVB. The surveillance of these pregnancies is controversial. Home-monitoring using a hand-held Doppler is a promising new approach. Methods: To obtain an overview of the current practice in Germany, we developed a web-based survey sent by the DEGUM (German Society of Ultrasound in Medicine) to ultrasound specialists. With the intention to evaluate practicability of home-monitoring, we instructed at-risk pregnant women to use a hand-held Doppler in the vulnerable period between 18 and 26 weeks at our university center. Results: There are trends but no clear consensus on surveillance, prophylaxis, and treatment of anti-Ro/La positive pregnant between specialists in Germany. Currently most experts do not offer home-monitoring but have a positive attitude towards its prospective use. Intensified fetal monitoring using a hand-held Doppler is feasible for pregnant women at risk and does not lead to frequent and unnecessary contact with the center. Conclusion: Evidence-based guidelines are needed to optimize the care of anti-Ro/La-positive pregnant women. Individual risk stratification could help pregnancy care of women at risk and is welcmed by most experts. Hand-held doppler monitoring is accepted by patients and prenatal medicine specialists as an option for intensified monitoring and can be included in an algorithm for surveillance.

Defining and targeting macrophage heterogeneity in the mammary gland and breast cancer

INTRODUCTION

Macrophages are innate immune cells that are associated with extensive phenotypic and functional plasticity and contribute to normal development, tissue homeostasis, and diseases such as cancer. In this review, we discuss the heterogeneity of tissue resident macrophages in the normal mammary gland and tumor-associated macrophages in breast cancer. Tissue resident macrophages are required for mammary gland development, where they have been implicated in promoting extracellular matrix remodeling, apoptotic clearance, and cellular crosstalk. In the context of cancer, tumor-associated macrophages are key drivers of growth and metastasis via their ability to promote matrix remodeling, angiogenesis, lymphangiogenesis, and immunosuppression.

METHOD

We identified and summarized studies in Pubmed that describe the phenotypic and functional heterogeneity of macrophages and the implications of targeting individual subsets, specifically in the context of mammary gland development and breast cancer. We also identified and summarized recent studies using single-cell RNA sequencing to identify and describe macrophage subsets in human breast cancer samples.

RESULTS

Advances in single-cell RNA sequencing technologies have yielded nuances in macrophage heterogeneity, with numerous macrophage subsets identified in both the normal mammary gland and breast cancer tissue. Macrophage subsets contribute to mammary gland development and breast cancer progression in differing ways, and emerging studies highlight a role for spatial localization in modulating their phenotype and function.

CONCLUSION

Understanding macrophage heterogeneity and the unique functions of each subset in both normal mammary gland development and breast cancer progression may lead to more promising targets for the treatment of breast cancer.

Suppressed transcript diversity and immune response in COVID-19 ICU patients: a longitudinal study

Understanding the dynamic changes in gene expression during Acute Respiratory Distress Syndrome (ARDS) progression in post-acute infection patients is crucial for unraveling the underlying mechanisms. Study investigates the longitudinal changes in gene/transcript expression patterns in hospital-admitted severe COVID-19 patients with ARDS post-acute SARS-CoV-2 infection. Blood samples were collected at three time points and patients were stratified into severe and mild ARDS, based on their oxygenation saturation (SpO2/FiO2) kinetics over 7 d. Decline in transcript diversity was observed over time, particularly in patients with higher severity, indicating dysregulated transcriptional landscape. Comparing gene/transcript-level analyses highlighted a rather limited overlap. With disease progression, a transition towards an inflammatory state was evident. Strong association was found between antibody response and disease severity, characterized by decreased antibody response and activated B cell population in severe cases. Bayesian network analysis identified various factors associated with disease progression and severity, viz. humoral response, TLR signaling, inflammatory response, interferon response, and effector T cell abundance. The findings highlight dynamic gene/transcript expression changes during ARDS progression, impact on tissue oxygenation and elucidate disease pathogenesis.

Atherosclerosis and Inflammation: Insights from the Theory of General Pathological Processes

Recent advances have greatly improved our understanding of the molecular mechanisms behind atherosclerosis pathogenesis. However, there is still a need to systematize this data from a general pathology perspective, particularly with regard to atherogenesis patterns in the context of both canonical and non-classical inflammation types. In this review, we analyze various typical phenomena and outcomes of cellular pro-inflammatory stress in atherosclerosis, as well as the role of endothelial dysfunction in local and systemic manifestations of low-grade inflammation. We also present the features of immune mechanisms in the development of productive inflammation in stable and unstable plaques, along with their similarities and differences compared to canonical inflammation. There are numerous factors that act as inducers of the inflammatory process in atherosclerosis, including vascular endothelium aging, metabolic dysfunctions, autoimmune, and in some cases, infectious damage factors. Life-critical complications of atherosclerosis, such as cardiogenic shock and severe strokes, are associated with the development of acute systemic hyperinflammation. Additionally, critical atherosclerotic ischemia of the lower extremities induces paracoagulation and the development of chronic systemic inflammation. Conversely, sepsis, other critical conditions, and severe systemic chronic diseases contribute to atherogenesis. In summary, atherosclerosis can be characterized as an independent form of inflammation, sharing similarities but also having fundamental differences from low-grade inflammation and various variants of canonical inflammation (classic vasculitis).

Contribution of S100A4-expressing fibroblasts to anti-SSA/Ro-associated atrioventricular nodal calcification and soluble S100A4 as a biomarker of clinical severity

Background

Fibrosis and dystrophic calcification disrupting conduction tissue architecture are histopathological lesions characterizing cardiac manifestations of neonatal lupus (cardiac-NL) associated with maternal anti-SSA/Ro antibodies.

Objectives

Increased appreciation of heterogeneity in fibroblasts encourages re-examination of existing models with the consideration of multiple fibroblast subtypes (and their unique functional differences) in mind. This study addressed fibroblast heterogeneity by examining expression of α-Smooth Muscle Actin (myofibroblasts) and of S100 Calcium-Binding Protein A4 (S100A4).

Methods

Using a previously established model of rheumatic scarring/fibrosis in vitro, supported by the evaluation of cord blood from cardiac-NL neonates and their healthy (anti-SSA/Ro-exposed) counterparts, and autopsy tissue from fetuses dying with cardiac-NL, the current study was initiated to more clearly define and distinguish the S100A4-positive fibroblast in the fetal cardiac environment.

Results

S100A4 immunostaining was observed in 4 cardiac-NL hearts with positional identity in the conduction system at regions of dystrophic calcification but not fibrotic zones, the latter containing only myofibroblasts. In vitro, fibroblasts cultured with supernatants of macrophages transfected with hY3 (noncoding ssRNA) differentiated into myofibroblasts or S100A4+ fibroblasts. Myofibroblasts expressed collagen while S100A4+ fibroblasts expressed pro-angiogenic cytokines and proteases that degrade collagen. Cord blood levels of S100A4 in anti-SSA/Ro-exposed neonates tracked disease severity and, in discordant twins, distinguished affected from unaffected.

Conclusions

These findings position the S100A4+ fibroblast alongside the canonical myofibroblast in the pathogenesis of cardiac-NL. Neonatal S100A4 levels support a novel biomarker of poor prognosis.

Impact of Siglecs on autoimmune diseases

Autoimmune diseases affect tens of millions of people just in the United States alone. Most of the available treatment options are aimed at reducing symptoms but do not lead to cures. Individuals affected with autoimmune diseases suffer from the imbalance between tolerogenic and immunogenic functions of their immune system. Often pathogenesis is mediated by autoreactive B and T cells that escape central tolerance and react against self-antigens attacking healthy tissues in the body. In recent years Siglecs, sialic-acid-binding immunoglobulin (Ig)-like lectins, have gained attention as immune checkpoints for therapeutic interventions to dampen excessive immune responses and to restore immune tolerance in autoimmune diseases. Many Siglecs function as inhibitory receptors suppressing activation signals in various immune cells through binding to sialic acid ligands as signatures of self. In this review, we highlight potential of Siglecs in suppressing immune responses causing autoimmune diseases. In particular, we cover the roles of CD22 and Siglec-G/Siglec-10 in regulating autoreactive B cell responses. We discuss several functions of Siglec-10 in the immune modulation of other immune cells, and the potential of therapeutic strategies for restoring immune tolerance by targeting Siglecs and expanding regulatory T cells. Finally, we briefly review efforts evaluating Siglec-based biomarkers to monitor autoimmune diseases.

The role of sialic acid-binding immunoglobulin-like-lectin-1 (siglec-1) in immunology and infectious disease

Siglec-1, also known as Sialoadhesin (Sn) and CD169 is highly conserved among vertebrates and with 17 immunoglobulin-like domains is Siglec-1 the largest member of the Siglec family. Expression of Siglec-1 is found primarily on dendritic cells (DCs), macrophages and interferon induced monocyte. The structure of Siglec-1 is unique among siglecs and its function as a receptor is also different compared to other receptors in this class as it contains the most extracellular domains out of all the siglecs. However, the ability of Siglec-1 to internalize antigens and to pass them on to lymphocytes by allowing dendritic cells and macrophages to act as antigen presenting cells, is the main reason that has granted Siglec-1's key role in multiple human disease states including atherosclerosis, coronary artery disease, autoimmune diseases, cell-cell signaling, immunology, and more importantly bacterial and viral infections. Enveloped viruses for example have been shown to manipulate Siglec-1 to increase their virulence by binding to sialic acids present on the virus glycoproteins allowing them to spread or evade immune response. Siglec-1 mediates dissemination of HIV-1 in activated tissues enhancing viral spread via infection of DC/T-cell synapses. Overall, the ability of Siglec-1 to bind a variety of target cells within the immune system such as erythrocytes, B-cells, CD8+ granulocytes and NK cells, highlights that Siglec-1 is a unique player in these essential processes.

Alternative splicing signatures of congenital heart disease and induced pluripotent stem cell-derived cardiomyocytes from congenital heart disease patients

Congenital heart disease (CHD) is the most serious congenital defect in newborns with higher mortality. Alternative splicing (AS) plays an essential role in numerous heart diseases. However, our understanding of the link between mRNA splicing and CHD in humans is limited. Here, we try to investigate the genome-wide AS events in CHD using bioinformatics methods. We collected available RNA-seq datasets of CHD-induced pluripotent stem cell-cardiomyocytes (iPSC-CMs) (including single ventricle disease [SVD] and tetralogy of Fallot [TOF]) and non-CHD from the Gene Expression Omnibus database. Then, we unprecedentedly performed AS profiles in CHD-iPSC-CMs and non-CHD-iPSC-CMs. The rMAPS was used to generate RNA-maps for the analysis of RNA-binding proteins' (RBPs) binding sites. We used StringTie to identify and quantify the transcripts from aligned RNA-Seq reads. A quantification matrix was generated with respect to different groups by extracting the transcripts per million values from StringTie outputs. Then, this matrix was used for correlation analysis between the expression level of RBP and AS level. Finally, we validated our AS results using RNA-seq data from CHD and non-CHD patient tissue samples. We identified CHD-related AS events using CHD-iPSC-CMs and CHD samples from patients. The results showed that functional enrichment of abnormal AS in SVD and TOF was transcription factor-related. Using rMAPS, RNA-binding proteins which regulated these AS were also determined, and RBP-AS regulatory network was constructed. Overall, we identified abnormal AS in CHD-iPSC-CMs and CHD samples from patients. We predicted AS regulators in SVD and TOF, respectively. At last, we concluded that AS played a key role in the pathogenesis of CHD.

Macrophage Dysfunction in Autoimmune Rheumatic Diseases and Atherosclerosis

One of the problems of modern medical science is cardiovascular pathology caused by atherosclerotic vascular lesions in patients with autoimmune rheumatic diseases (ARDs). The similarity between the mechanisms of the immunopathogenesis of ARD and chronic low-grade inflammation in atherosclerosis draws attention. According to modern concepts, chronic inflammation associated with uncontrolled activation of both innate and acquired immunity plays a fundamental role in all stages of ARDs and atherosclerotic processes. Macrophage monocytes play an important role among the numerous immune cells and mediators involved in the immunopathogenesis of both ARDs and atherosclerosis. An imbalance between M1-like and M2-like macrophages is considered one of the causes of ARDs. The study of a key pathogenetic factor in the development of autoimmune and atherosclerotic inflammation-activated monocyte/macrophages will deepen the knowledge of chronic inflammation pathogenesis.

An Overview of Neonatal Lupus with Anti-Ro Characteristics

Neonatal lupus erythematosus (NLE) is a syndrome of clinical symptoms observed in neonates born to mothers with antibodies to soluble antigens of the cell nucleus. The main factors contributing to the pathogenesis of this disease are anti-Sjögren Syndrome A (anti-SS-A) antibodies, known as anti-Ro, and anti-Sjögren Syndrome B (anti-SS-B) antibodies, known as anti-La. Recent publications have also shown the significant role of anti-ribonucleoprotein antibodies (anti-RNP). Seropositive mothers may have a diagnosed rheumatic disease or they can be asymptomatic without diagnosis at the time of childbirth. These antibodies, after crossing the placenta, may trigger a cascade of inflammatory reactions. The symptoms of NLE can be divided into reversible symptoms, which concern skin, hematological, and hepatological changes, but 2% of children develop irreversible symptoms, which include disturbances of the cardiac stimulatory and conduction system. Preconceptive care and pharmacological prophylaxis of NLE in the case of mothers from the risk group are important, as well as the monitoring of the clinical condition of the mother and fetus throughout pregnancy and the neonatal period. The aim of this manuscript is to summarize the previous literature and current state of knowledge about neonatal lupus and to discuss the role of anti-Ro in the inflammatory process.

Autoimmunity in 2019

Based on the PubMed data, we have been performing a yearly evaluation of the publications related to autoimmune diseases and immunology to ascertain the relative weight of the former in the scientific literature. It is particularly intriguing to observe that despite the numerous new avenues of immune-related mechanisms, such as cancer immunotherapy, the proportion of immunology manuscripts related to autoimmunity continues to increase and has been approaching 20% in 2019. As in the previous 13 years, we performed an arbitrary selection of the peer-reviewed articles published by the major dedicated Journals and discussed the common themes which continue to outnumber peculiarites in autoimmune diseases. The investigated areas included systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), psoriatic arthritis (PsA), autoantibodies (autoAbs), and common therapeutic avenues and novel pathogenic mechanisms for autoimmune conditions. Some examples include new pathogenetic evidence which is well represented by IL21 or P2X7 receptor (P2X7R) in SLE or the application of single-cell RNA sequencing (scRNA-seq), mass cytometry, bulk RNA sequencing (RNA-seq), and flow cytometry for the analysis of different cellular populations in RA. Cumulatively and of interest to the clinicians, a large number of findings continue to underline the importance of a strict relationship between basic and clinical science to define new pathogenetic and therapeutic developments. The therapeutic pipeline in autoimmunity continues to grow and maintain a constant flow of new molecules, as well illustrated in RA and PsA, and this is most certainly derived from the new basic evidence and the high-throughput tools applied to autoimmune diseases.

Type I IFN system activation in newborns exposed to Ro/SSA and La/SSB autoantibodies in utero

OBJECTIVE

In utero exposure of the fetus to Ro/La autoantibodies may lead to congenital heart block (CHB). In the mother, these autoantibodies are associated with activation of the type I interferon (IFN)-system. As maternal autoantibodies are transferred to the fetus during pregnancy, we investigated whether the type I IFN-system is activated also in newborns of anti-Ro/La positive mothers, and whether fetal IFN activation is affected by maternal immunomodulatory treatment.

METHODS

Blood drawn at birth from anti-Ro/La positive mothers, their newborns and healthy control pairs was separated into plasma and peripheral blood mononuclear cells (PBMC). PBMC were analysed directly or cultured. mRNA expression was analysed by microarrays, cell surface markers by flow cytometry, and IFNα levels by immunoassays.

RESULTS

We observed increased expression of IFN-regulated genes and elevated plasma IFNα levels not only in anti-Ro/La positive women, but also in their newborns. CD14⁺ monocytes of both anti-Ro/La positive mothers and their neonates showed increased expression of Sialic acid-binding Ig-like lectin-1, indicating cellular activation. Notably, the IFN score of neonates born to mothers receiving immunomodulatory treatment was similar to that of controls, despite persistent IFN activation in the mothers. In both maternal and neonatal PBMC, IFNα production was induced when cells were cultured with anti-Ro/La positive plasma.

CONCLUSIONS

Ro/La autoantibody-exposed neonates at risk of CHB have signs of an activated immune system with an IFN signature. This study further demonstrates that neonatal cells can produce IFNα when exposed to autoantibody-containing plasma, and that maternal immunomodulatory treatment may diminish the expression of IFN-regulated genes in the fetus.

Function of Macrophages in Disease: Current Understanding on Molecular Mechanisms

Tissue-resident macrophages (TRMs) are heterogeneous populations originating either from monocytes or embryonic progenitors, and distribute in lymphoid and non-lymphoid tissues. TRMs play diverse roles in many physiological processes, including metabolic function, clearance of cellular debris, and tissue remodeling and defense. Macrophages can be polarized to different functional phenotypes depending on their origin and tissue microenvironment. Specific macrophage subpopulations are associated with disease progression. In studies of fate-mapping and single-cell RNA sequencing methodologies, several critical molecules have been identified to induce the change of macrophage function. These molecules are potential markers for diagnosis and selective targets for novel macrophage-mediated treatment. In this review, we discuss some of the recent findings regarding less-known molecules and new functions of well-known molecules. Understanding the mechanisms of these molecules in macrophages has the potential to yield new macrophage-mediated treatments or diagnostic approaches to disease.

First trimester combined screening test for aneuploidies in anti-Ro carriers pregnant women

INTRODUCTION

Anti-Ro/SSA and anti-La/SSB antibodies are associated with neonatal lupus and congenital heart block. Controversial results regarding perinatal outcomes are found and less is known about aneuploidy screening. The hypothesis is that the presence of anti-Ro and/or anti-La antibodies influences the levels of PAPP-A and ß-HCG, thus interfering in the calculation of risk of aneuploidies.

MATERIAL AND METHODS

Fifty-five anti-Ro/SSA positive pregnant women were included. The demographic characteristics and laboratory variables were studied. Data concerning chromosomopaties screening were also recorded.

RESULTS

PAPP-A and β-HCG levels were calculated (as well as NT and CRL) and compared with a healthy cohort of 12971 pregnant women. PAPP-A levels in mg/mL were lower significatively. In anti-La/SS-B cohort, significant differences were found in PAPP-A in mg/mL and in MoM. Combined risks for Down syndrome (DS) in both groups were higher but the differences were due to age.

CONCLUSIONS

Serum levels of PAPP-A were significative lower but not confirmed when adjusted to MoM. This will have to be confirmed in studies with a larger number of patients and to check whether there is an impact in the calculation of DS risk or not. They could represent a group of pregnant women with significantly a higher risk of adverse perinatal outcome. Key Points • Pregnant patients with anti-Ro/SS-A ant/or anti-La/SS-B antibodies have low PAPP-A levels compared with pregnant women without antibodies. • PAPP-A levels are used in obstetrics for aneuploidies screening in the first trimester, so in these patients, there could be more false positive screening. • In these findings are verified in trials with a larger number of patients, a correction variable would have to be applied for the aneuploidies screening calculation. • Also, low PAPP-A levels are correlated with poor placentation, that is to say, more risk of miscarriages, small fetus for gestational age, and preeclampsia. This is another topic to take into consideration in this population.

Cell atlas of the foetal human heart and implications for autoimmune-mediated congenital heart block

Aims

Investigating human heart development and applying this to deviations resulting in disease is incomplete without molecular characterization of the cell types required for normal functioning. We investigated foetal human heart single-cell transcriptomes from mid-gestational healthy and anti-SSA/Ro associated congenital heart block (CHB) samples.

Methods and results

Three healthy foetal human hearts (19th to 22nd week of gestation) and one foetal heart affected by autoimmune-associated CHB (21st week of gestation) were subjected to enzymatic dissociation using the Langendorff preparation to obtain single-cell suspensions followed by 10× Genomics- and Illumina-based single-cell RNA-sequencing (scRNA-seq). In addition to the myocytes, fibroblasts, immune cells, and other minor cell types, previously uncharacterized diverse sub-populations of endothelial cells were identified in the human heart. Differential gene expression analysis revealed increased and heterogeneous interferon responses in varied cell types of the CHB heart compared with the healthy controls. In addition, we also identified matrisome transcripts enriched in CHB stromal cells that potentially contribute to extracellular matrix deposition and subsequent fibrosis.

Conclusion

These data provide an information-rich resource to further our understanding of human heart development, which, as illustrated by comparison to a heart exposed to a maternal autoimmune environment, can be leveraged to provide insight into the pathogenesis of disease.

Home fetal heart rate monitoring in anti Ro/SSA positive pregnancies: Literature review and case report

Anti-Ro/SSA antibodies are associated with a risk of 1-2 % to develop complete atrioventricular block (AVB) in fetuses of positive mothers. Complete AVB is irreversible, but studies suggest that anti-inflammatory treatment during the transition period from a normal fetal heart rate (FHR) to an AVB might stop this progression and restore sinus rhythm. The most efficient method for diagnostic evaluation of this arrhythmia is the pulsed-Doppler fetal echocardiography. However, weekly or bi-weekly recommended fetal echocardiographic surveillance can rarely identify an AVB in time for treatment success, also because the transition from a normal rhythm to a third degree AVB is very fast. Daily FHR monitoring in a medical facility could increase the chances of identifying the AVB onset but is difficult to realize. For this reason, an alternative method of FHR monitoring, performed directly by mothers in their home context, has been recently proposed. We present a case report utilizing this approach and review the current evidence about this condition.

Hydroxychloroquine to Prevent Recurrent Congenital Heart Block in Fetuses of Anti-SSA/Ro-Positive Mothers

BACKGROUND

Experimental and clinical evidence support the role of macrophage Toll-like receptor signaling in maternal anti-SSA/Ro-mediated congenital heart block (CHB).

OBJECTIVES

Hydroxychloroquine (HCQ), an orally administered Toll-like receptor antagonist widely used in lupus including during pregnancy, was evaluated for efficacy in reducing the historical 18% recurrence rate of CHB.

METHODS

This multicenter, open-label, single-arm, 2-stage clinical trial was designed using Simon's optimal approach. Anti-SSA/Ro-positive mothers with a previous pregnancy complicated by CHB were recruited (n = 19 Stage 1; n = 35 Stage 2). Patients received 400 mg daily of HCQ prior to completion of gestational week 10, which was maintained through pregnancy. The primary outcome was 2° or 3° CHB any time during pregnancy, and secondary outcomes included isolated endocardial fibroelastosis, 1° CHB at birth and skin rash.

RESULTS

By intention-to-treat (ITT) analysis, 4 of 54 evaluable pregnancies resulted in a primary outcome (7.4%; 90% confidence interval: 3.4% to 15.9%). Because 9 mothers took potentially confounding medications (fluorinated glucocorticoids and/or intravenous immunoglobulin) after enrollment but prior to a primary outcome, to evaluate HCQ alone, 9 additional mothers were recruited and followed the identical protocol. In the per-protocol analysis restricted to pregnancies exposed to HCQ alone, 4 of 54 (7.4%) fetuses developed a primary outcome as in the ITT. Secondary outcomes included mild endocardial fibroelastosis (n = 1) and cutaneous neonatal lupus (n = 4).

CONCLUSIONS

These prospective data support that HCQ significantly reduces the recurrence of CHB below the historical rate by >50%, suggesting that this drug should be prescribed for secondary prevention of fetal cardiac disease in anti-SSA/Ro-exposed pregnancies. (Preventive Approach to Congenital Heart Block With Hydroxychloroquine [PATCH]; NCT01379573).

Interferons and innate immune activation in autoimmune congenital heart block

Autoimmune congenital heart block (CHB) may develop in foetuses of women carrying anti-Ro/SSA and La/SSB autoantibodies and is characterized by disruption of signal conduction at the atrioventricular (AV) node, resulting in partial or complete AV block. If not fatal in utero, complete CHB typically requires lifelong cardiac pacing. No treatment has so far been unequivocally demonstrated to prevent or treat autoimmune CHB, and the relatively low incidence (1%-5%) and recurrence (12%-16%) rates of second/third-degree AV block add to the complexity of managing pregnancies in women with anti-Ro/La antibodies. Altogether, a better understanding of events leading to development of autoimmune CHB is needed to improve surveillance and treatment strategies. In the past decade, studies have started to look beyond the role of maternal autoantibodies in disease pathogenesis to assess other contributing factors such as foetal genetics and, more recently, immune responses in foetuses and neonates of anti-Ro/La antibody-positive women. In this review, we provide an update on the epidemiology, clinical presentation and current treatment approaches of autoimmune CHB, summarize the previously proposed pathogenic mechanisms implicating maternal autoantibodies, and discuss the recent findings of type I interferon (IFN) and innate immune activation in foetuses with autoimmune CHB and in neonates of anti-Ro/La antibody-positive mothers, and how these may contribute to autoimmune CHB pathogenesis.

Natural killer cells and type II interferon in Ro/SSA and La/SSB autoantibody-exposed newborns at risk of congenital heart block

OBJECTIVE

Congenital heart block (CHB) with immune cell infiltration develops in the fetus after exposure to maternal Ro/La autoantibodies. CHB-related serology has been extensively studied, but reports on immune-cell profiles of anti-Ro/La-exposed neonates are lacking. In the current study, we characterised circulating immune-cell populations in anti-Ro/La+mothers and newborns, and explored potential downstream effects of skewed neonatal cell populations.

METHODS

In total, blood from mothers (n=43) and neonates (n=66) was sampled at birth from anti-Ro/La+ (n=36) and control (n=30) pregnancies with or without rheumatic disease and CHB. Flow cytometry, microarrays and ELISA were used for characterising cells and plasma.

RESULTS

Similar to non-pregnant systemic lupus erythematosus and Sjögren-patients, anti-Ro/La+mothers had altered B-cell subset frequencies, relative T-cell lymphopenia and lower natural killer (NK)-cell frequencies. Surprisingly, their anti-Ro/La exposed neonates presented higher frequencies of CD56^dimCD16^hi NK cells (p<0.01), but no other cell frequency differences compared with controls. Type I and II interferon (IFN) gene-signatures were revealed in neonates of anti-Ro/La+ pregnancy, and exposure of fetal cardiomyocytes to type I IFN induced upregulation of several NK-cell chemoattractants and activating ligands. Intracellular flow cytometry revealed IFNγ production by NK cells, CD8⁺ and CD4⁺ T cells in anti-Ro/La exposed neonates. IFNγ was also detectable in their plasma.

CONCLUSION

Our study demonstrates an increased frequency of NK cells in anti-Ro/La exposed neonates, footprints of type I and II IFN and an upregulation of ligands activating NK cells in fetal cardiac cells after type I IFN exposure. These novel observations demonstrate innate immune activation in neonates of anti-Ro/La+pregnancy, which could contribute to the risk of CHB.

Monocyte and CD4+ T-cell antiviral and innate responses associated with HIV-1 inflammation and cognitive impairment

OBJECTIVE

Mechanisms underlying immune activation and HIV-associated neurocognitive disorders (HAND) in untreated chronic infection remain unclear. The objective of this study was to identify phenotypic and transcriptional changes in blood monocytes and CD4 T cells in HIV-1-infected and uninfected individuals and elucidate processes associated with neurocognitive impairment.

DESIGN

A group of chronically HIV-1-infected Thai individuals (n = 19) were selected for comparison with healthy donor controls (n = 10). Infected participants were further classified as cognitively normal (n = 10) or with HAND (n = 9). Peripheral monocytes and CD4 T cells were phenotyped by flow cytometry and simultaneously isolated for multiplex qPCR-targeted gene expression profiling directly ex vivo. The frequency of HIV-1 RNA-positive cells was estimated by limiting dilution cell sorting.

RESULTS

Expression of genes and proteins involved in cellular activation and proinflammatory immune responses was increased in monocytes and CD4 T cells from HIV-1-infected relative to uninfected individuals. Gene expression profiles of both CD4 T cells and monocytes correlated with soluble markers of inflammation in the periphery (P < 0.05). By contrast, only modest differences in gene programs were observed between cognitively normal and HAND cases. These included increased monocyte surface CD169 protein expression relative to cognitively normal (P = 0.10), decreased surface CD163 expression relative to uninfected (P = 0.02) and cognitively normal (P = 0.06), and downregulation of EMR2 (P = 0.04) and STAT1 (P = 0.02) relative to cognitively normal.

CONCLUSION

Our data support a model of highly activated monocytes and CD4 T cells associated with inflammation in chronic HIV-1 infection, but impaired monocyte anti-inflammatory responses in HAND compared with cognitively normal.

A Broader Perspective on Anti-Ro Antibodies and Their Fetal Consequences-A Case Report and Literature Review

The presence of maternal Anti-Ro/Anti-La antibodies causes a passively acquired autoimmunity that may be associated with serious fetal complications. The classic example is the autoimmune-mediated congenital heart block (CHB) which is due in most cases to the transplacental passage of Anti-Ro/Anti-La antibodies. The exact mechanisms through which these pathologic events arise are linked to disturbances in calcium channels function, impairment of calcium homeostasis and ultimately apoptosis, inflammation and fibrosis. CHB still represents a challenging diagnosis and a source of debate regarding the best management. As the third-degree block is usually irreversible, the best strategy is risk awareness and prevention. Although CHB is a rare occurrence, it affects one in 20,000 live births, with a high overall mortality rate (up to 20%, with 70% of in utero deaths). There is also concern over the lifelong consequences, as most babies need a pacemaker. This review aims to offer, apart from the data needed for a better understanding of the issue at hand, a broader perspective of the specialists directly involved in managing this pathology: the rheumatologist, the maternal-fetal specialist and the cardiologist. To better illustrate the theoretical facts presented, we also include a representative clinical case.

Sialic Acid-Siglec Axis as Molecular Checkpoints Targeting of Immune System: Smart Players in Pathology and Conventional Therapy

The sialic acid-based molecular mimicry in pathogens and malignant cells is a regulatory mechanism that leads to cross-reactivity with host antigens resulting in suppression and tolerance in the immune system. The interplay between sialoglycans and immunoregulatory Siglec receptors promotes foreign antigens hiding and immunosurveillance impairment. Therefore, molecular targeting of immune checkpoints, including sialic acid-Siglec axis, is a promising new field of inflammatory disorders and cancer therapy. However, the conventional drugs used in regular management can interfere with glycome machinery and exert a divergent effect on immune controlling systems. Here, we focus on the known effects of standard therapies on the sialoglycan-Siglec checkpoint and their importance in diagnosis, prediction, and clinical outcomes.

A review of fetal and neonatal consequences of maternal systemic lupus erythematosus

Systemic lupus erythematosus (SLE) primarily affects women of childbearing age and is commonly seen in pregnancy. The physiologic and immunologic changes of pregnancy may alter the course of SLE and impact maternal, fetal, and neonatal health. Multidisciplinary counseling before and during pregnancy from rheumatology, maternal fetal medicine, obstetrics, and pediatric cardiology is critical. Transplacental passage of autoantibodies, present in about 40% of women with SLE, can result in neonatal lupus (NL). NL can consist of usually permanent cardiac manifestations, including conduction system and myocardial disease, as well as transient cutaneous, hematologic, and hepatic manifestations. Additionally, women with SLE are more likely to develop adverse pregnancy outcomes such as preeclampsia, fetal growth restriction, and preterm birth, perhaps due to an underlying effect on placentation. This review describes the impact of SLE on maternal and fetal health by trimester, beginning with prepregnancy optimization of maternal health. This is followed by a discussion of NL and the current understanding of the epidemiology and pathophysiology of anti-Ro/La mediated cardiac disease, as well as screening, treatment, and methods for prevention. Finally discussed is the known increase in preeclampsia and fetal growth issues in women with SLE that can lead to iatrogenic preterm delivery.

Common innate pathways to autoimmune disease

Until recently, autoimmune disease research has primarily been focused on elucidating the role of the adaptive immune system. In the past decade or so, the role of the innate immune system in the pathogenesis of autoimmunity has increasingly been realized. Recent findings have elucidated paradigm-shifting concepts, for example, the implications of "trained immunity" and a dysbiotic microbiome in the susceptibility of predisposed individuals to clinical autoimmunity. In addition, the application of modern technologies such as the quantum dot (Qdot) system and 'Omics' (e.g., genomics, proteomics, and metabolomics) data-processing tools has proven fruitful in revisiting mechanisms underlying autoimmune pathogenesis and in identifying novel therapeutic targets. This review highlights recent findings discussed at the American Autoimmune Related Disease Association (AARDA) 2019 colloquium. The findings covering autoimmune diseases and autoinflammatory diseases illustrate how new developments in common innate immune pathways can contribute to the better understanding and management of these immune-mediated disorders.

Autoimmune Congenital Heart Block: A Review of Biomarkers and Management of Pregnancy

Autoimmune Congenital Heart Block (CHB) is an immune-mediated disease due to transplacental passage of circulating anti-Ro/SSA and anti-La/SSB autoantibodies. It occurs in 2% of anti-Ro/SSA-exposed pregnancies, and recurrence rate is nine times higher in subsequent pregnancies. Aim of this review is to identify biomarkers of CHB and treatment strategies. The Ro-system is constituted by two polypeptides targeted by the anti-Ro52 and anti-Ro60 autoantibodies. The central portion of Ro52 (p200), more than the full amino-acid sequence of Ro-52, is recognized to be the fine specificity of anti-Ro associated to the highest risk of cardiac damage. If anti-p200 antibody should be tested, as biomarker of CHB, over standard commercial ELISAs is still debated. Recent studies indicate that type I-Interferon (IFN) can activate fibroblasts in fetal heart. In the mother the anti-Ro/La antibodies activate the type I IFN-signature, and maternal IFN-regulated genes correlate with a similar neonatal IFN-gene expression. Evaluation of maternal IFN-signature could be used as novel biomarker of CHB. The measurement of "mechanical" PR interval with weekly fetal echocardiogram (ECHO) from 16 to at least 24 weeks of gestation is strongly recommended for CHB prenatal diagnosis. However, ECHO screening presents some limitations due to difficult identification of first-degree block and possible occurrence of a complete block from a normal rhythm in few days. Maternal administration of Hydroxychloroquine from the tenth week of gestation, modulating toll-like receptor and autoantibody-dependent type I IFN activation on the fetus, has an important role in preventing CHB in pregnant women with high risk for recurrent CHB.

Autoimmune-mediated congenital heart block

Autoimmune-mediated congenital heart block (CHB) is a severe manifestation of neonatal lupus in which conduction tissues of the fetal heart are damaged. This occurs due to passive transference of maternal anti-SSA/Ro and anti-SSB/La autoantibodies and subsequent inflammation and fibrosis of the atrioventricular (AV) node. Notably, the disease manifests after the fetal heart has structurally developed, ruling out other anatomical abnormalities that could otherwise contribute to the block of conduction. Complete AV block is irreversible and the most common manifestation of CHB, although other cardiac complications such as endocardial fibroelastosis (EFE), dilated cardiomyopathy, and valvular insufficiency have been observed. In this review, we detail the classification, prevalence, pathogenesis, and clinical management recommendations for autoimmune CHB.

Keeping upbeat to prevent the heartbreak of anti-Ro/SSA pregnancy

Linked Comment: Ultrasound Obstet Gynecol 2019; 54: 87-95.

Congenital heart block: Pace earlier (Childhood) than later (Adulthood)

Congenital complete heart block (CCHB) occurs in 2-5% of pregnancies with positive anti-Ro/SSA and/or anti-La/SSB antibodies, and has a recurrence rate of 12-25% in a subsequent pregnancy. After trans-placental passage, these autoantibodies attack and destroy the atrioventricular (AV) node in susceptible fetuses with the highest-risk period observed between 16 and 28 weeks' gestational age. Many mothers are asymptomatic carriers, while <1/3 have a preexisting diagnosis of a rheumatic disease. The mortality of CCHB is predominant in utero and in the first months of life, reaching 15-30%. The diagnosis of CCHB can be confirmed by fetal echocardiography before birth and by electrocardiography after birth. Whether early in-utero detection and treatment might prevent or reverse this condition remains controversial. In addition to autoantibody-associated CCHB, there is also an isolated (absent structural heart disease) nonimmune early- or late-onset heart block detected later in childhood that may be associated with specific genetic markers or other pathogenic mechanisms. In isolated immune or non-immune CCHB, cardiac pacemakers are implanted in symptomatic patients, however, data on the natural history of CCHB in the adult life indicate that all patients, even if asymptomatic, should receive a pacemaker when first diagnosed. However, important issues have emerged in these patients wherein life-long conventional right ventricular apical pacing may produce left ventricular dysfunction (pacing-induced cardiomyopathy) necessitating a priori alternate site pacing or subsequent upgrading to biventricular pacing. All these issues are herein reviewed and two algorithms are proposed for diagnosis and management of CCHB in the fetus and in the older individual.