Immune dysregulation, polyendocrinopathy, enteropathy, X-linked syndrome and recurrent intrauterine fetal death

The Landscape of Point Mutations in Human Protein Coding Genes Leading to Pregnancy Loss

Pregnancy loss is the most frequent complication of a pregnancy which is devastating for affected families and poses a significant challenge for the health care system. Genetic factors are known to play an important role in the etiology of pregnancy loss; however, despite advances in diagnostics, the causes remain unexplained in more than 30% of cases. In this review, we aggregated the results of the decade-long studies into the genetic risk factors of pregnancy loss (including miscarriage, termination for fetal abnormality, and recurrent pregnancy loss) in euploid pregnancies, focusing on the spectrum of point mutations associated with these conditions. We reviewed the evolution of molecular genetics methods used for the genetic research into causes of pregnancy loss, and collected information about 270 individual genetic variants in 196 unique genes reported as genetic cause of pregnancy loss. Among these, variants in 18 genes have been reported by multiple studies, and two or more variants were reported as causing pregnancy loss for 57 genes. Further analysis of the properties of all known pregnancy loss genes showed that they correspond to broadly expressed, highly evolutionary conserved genes involved in crucial cell differentiation and developmental processes and related signaling pathways. Given the features of known genes, we made an effort to construct a list of candidate genes, variants in which may be expected to contribute to pregnancy loss. We believe that our results may be useful for prediction of pregnancy loss risk in couples, as well as for further investigation and revealing genetic etiology of pregnancy loss.

Gestational Development of the Human Immune System

Building an immune system is a monumental task critical to the survival of the fetus and newborn. A functional fetal immune system must complement the maternal immune system in handling in utero infection; abstain from damaging non-self-reactions that would compromise the materno-fetal interface; mobilize in response to infection and equip mucosal tissues for pathogen exposure at birth. There is growing appreciation that immune cells also have noncanonical roles in development and specifically may contribute to tissue morphogenesis. In this review we detail how hematopoietic and lymphoid organs jointly establish cellular constituents of the immune system; how these constituents are organized in 2 mucosal sites-gut and lung-where early life immune function has long-term consequences for health; and how exemplar diseases of prematurity and inborn errors of immunity reveal dominant pathways in prenatal immunity.

Predicting first-trimester outcome of embryos with cardiac activity in women with recurrent spontaneous abortion

Objective

This study was performed to evaluate the capability of routine clinical indicators to predict the early outcome of embryos with cardiac activity in women with recurrent spontaneous abortion (RSA).

Methods

A retrospective cohort study of pregnant women with a history of RSA in a Chinese tertiary hospital was performed using unadjusted and multivariable logistic regression.

Results

Of 789 pregnant women with RSA, 625 (79.21%) had ongoing pregnancy, whereas 164 (20.79%) developed abortion before 20 full weeks of gestational age even after embryonic heart motion was detected. The final model had an area under the curve of 0.81 (95% confidence interval, 0.78–0.84) with a sensitivity of 74.39%, a specificity of 76.00%, and a false-positive rate of 52.32% at a fixed detection rate of 90%.

Conclusions

The combination of multiple routine clinical indicators was valuable in predicting the early outcome of embryos with cardiac activity in viable pregnancies with RSA. However, this model might result in a high false-positive rate with a fixed detection rate of 90%; other markers must be investigated to identify first-trimester RSA once positive embryonic heart motion is established.

A hemizygous mutation in the FOXP3 gene (IPEX syndrome) resulting in recurrent X-linked fetal hydrops: a case report

Background

Fetal hydrops is excessive extravasation of fluid into the third space in a fetus, which could be due to a wide differential of underlying pathology. IPEX (immune dysregulation, polyendocrinopathy, enteropathy, X-linked) syndrome primarily affects males. It is a monogenic primary immunodeficiency syndrome of X-linked recessive inheritance due to FOXP3 gene variants. It is characterised by the development of multiple autoimmune disorders in affected individuals.

Case presentation

We present a rare cause of male fetal hydrops in the context of IPEX syndrome and discuss FOXP3 gene variants as a differential for ‘unexplained’ fetal hydrops that may present after the first trimester.

Discussion and conclusions

In all similar cases, the pathological process begins during intrauterine life. Furthermore, there are no survivors described. Consequently, this variant should be considered as a severe one, associated with intrauterine life onset and fatal course, i.e., the most severe IPEX phenotype.

Helios enhances the preferential differentiation of human fetal CD4+ naïve T cells into regulatory T cells

T cell receptor (TCR) stimulation and cytokine cues drive the differentiation of CD4⁺ naïve T cells into effector T cell populations with distinct proinflammatory or regulatory functions. Unlike adult naïve T cells, human fetal naïve CD4⁺ T cells preferentially differentiate into FOXP3⁺ regulatory T (T_reg) cells upon TCR activation independent of exogenous cytokine signaling. This cell-intrinsic predisposition for T_reg differentiation is implicated in the generation of tolerance in utero; however, the underlying mechanisms remain largely unknown. Here, we identify epigenetic and transcriptional programs shared between fetal naïve T and committed T_reg cells that are inactive in adult naïve T cells and show that fetal-derived induced T_reg (iT_reg) cells retain this transcriptional program. We show that a subset of T_reg-specific enhancers is accessible in fetal naïve T cells, including two active superenhancers at Helios Helios is expressed in fetal naïve T cells but not in adult naïve T cells, and fetal iT_reg cells maintain Helios expression. CRISPR-Cas9 ablation of Helios in fetal naïve T cells impaired their differentiation into iT_reg cells upon TCR stimulation, reduced expression of immunosuppressive genes in fetal iT_reg cells such as IL10, and increased expression of proinflammatory genes including IFNG Consequently, Helios knockout fetal iT_reg cells had reduced IL-10 and increased IFN-γ cytokine production. Together, our results reveal important roles for Helios in enhancing preferential fetal T_reg differentiation and fine-tuning eventual T_reg function. The T_reg-biased programs identified within fetal naïve T cells could potentially be used to engineer enhanced iT_reg populations for adoptive cellular therapies.

Clinical, Immunological, and Genetic Features in Patients with Immune Dysregulation, Polyendocrinopathy, Enteropathy, X-linked (IPEX) and IPEX-like Syndrome

BACKGROUND

Immune dysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX) syndrome is a rare inborn error of immunity caused by mutations in the forkhead box P3 (FOXP3) gene.

OBJECTIVE

In this study, we conducted a systematic review of patients with IPEX and IPEX-like syndrome to delineate differences in these 2 major groups.

METHODS

The literature search was performed in PubMed, Web of Science, and Scopus databases, and demographic, clinical, immunologic, and molecular data were compared between the IPEX and IPEX-like groups.

RESULTS

A total of 459 patients were reported in 148 eligible articles. Major clinical differences between patients with IPEX and IPEX-like syndrome were observed in rates of pneumonia (11% vs 31%, P < .001), bronchiectasis (0.3% vs 14%, P < .001), diarrhea (56% vs 42%, P = .020), and organomegaly (10% vs 23%, P = .001), respectively. Eosinophilia (95% vs 100%), low regulatory T-cell count (68% vs 50%), and elevated IgE (87% vs 61%) were the most prominent laboratory findings in patients with IPEX and IPEX-like syndrome, respectively. In the IPEX group, a lower mortality rate was observed among patients receiving hematopoietic stem cell transplantation (HSCT) (24%) compared with other patients (43%), P = .008; however, in the IPEX-like group, it was not significant (P = .189).

CONCLUSIONS

Patients with IPEX syndrome generally suffer from enteropathy, autoimmunity, dermatitis, eosinophilia, and elevated serum IgE. Despite similarities in their clinical presentations, patients with IPEX-like syndrome are more likely to present common variable immunodeficiency-like phenotype such as respiratory tract infections, bronchiectasis, and organomegaly. HSCT is currently the only curative therapy for both IPEX and IPEX-like syndrome and may result in favorable outcome.

Intrauterine IPEX

IPEX is one of the few Inborn Errors of Immunity that may manifest in the fetal period, and its intrauterine forms certainly represent the earliest human autoimmune diseases. Here, we review the clinical, histopathologic, and genetic findings from 21 individuals in 11 unrelated families, with nine different mutations, described as cases of intrauterine IPEX. Recurrent male fetal death (multigenerational in five families) due to hydrops in the midsemester of pregnancy was the commonest presentation (13/21). Noteworthy, in the affected families, there were only fetal- or perinatal-onset cases, with no affected individuals presenting milder forms with later-life manifestation. Most alive births were preterm (5/6). Skin desquamation and intrauterine growth restriction were observed in part of the cases. Fetal ultrasonography showed hyperechoic bowel or dilated bowel loops in the five cases with available imaging data. Histopathology showed multi-visceral infiltrates with T lymphocytes and other cells, including eosinophils, the pancreas being affected in most of the cases (11/21) and as early as at 18 weeks of gestational age. Regarding the nine FOXP3 mutations found in these cases, six determine protein truncation and three predictably impair protein function. Having found distinct presentations for the same FOXP3 mutation in different families, we resorted to the mouse system and showed that the scurfy mutation also shows divergent severity of phenotype and age of death in C57BL/6 and BALB/c backgrounds. We also reviewed age-of-onset data from other monogenic Tregopathies leading to IPEX-like phenotypes. In monogenic IPEX-like syndromes, the intrauterine onset was only observed in two kindreds with IL2RB mutations, with two stillbirths and two premature neonates who did not survive. In conclusion, intrauterine IPEX cases seem to constitute a particular IPEX subgroup, certainly with the most severe clinical presentation, although no strict mutation-phenotype correlations could be drawn for these cases.

Recurrent Non Immune Fetal Hydrops Associated With IPEX Syndrome

Immune dysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX) is a clinical syndrome associated with mutations in FOXP3 and consequent abnormalities of T regulatory cells. Affected males typically die in infancy or early childhood from a variety of autoimmune conditions. Reports of recurrent pregnancy loss of male fetuses in these families have been accompanied by descriptions of nonimmune fetal hydrops, with or without additional fetal anomalies. Here, we report an additional family affected by IPEX with a novel mutation leading to recurrent second trimester fetal hydrops and intrauterine fetal demise with associated fetal anomalies. This report underscores how careful genetic and pathologic analysis of even midtrimester fetuses can provide important information impacting an entire family. It also further substantiates the use of broad, symptom-targeted genetic screening panels in cases of recurrent pregnancy loss even in the absence of a remarkable pedigree.

Tregopathies: Monogenic diseases resulting in regulatory T-cell deficiency

Monogenic diseases of the immune system, also known as inborn errors of immunity, are caused by single-gene mutations resulting in immune deficiency and dysregulation. More than 350 diseases have been described to date, and the number is rapidly expanding, with increasing availability of next-generation sequencing facilitating the diagnosis. The spectrum of immune dysregulation is wide, encompassing deficiencies in humoral, cellular, innate, and adaptive immunity; phagocytosis; and the complement system, which lead to autoinflammation and autoimmunity. Multiorgan autoimmunity is a dominant symptom when genetic mutations lead to defects in molecules essential for the development, survival, and/or function of regulatory T (Treg) cells. Studies of "Tregopathies" are providing critical mechanistic information on Treg cell biology, the role of Treg cell-associated molecules, and regulation of peripheral tolerance in human subjects. The pathogenic immune networks underlying these diseases need to be dissected to apply and develop immunomodulatory treatments and design curative treatments using cell and gene therapy. Here we review the pathogenetic mechanisms, clinical presentation, diagnosis, and current and future treatments of major known Tregopathies caused by mutations in FOXP3, CD25, cytotoxic T lymphocyte-associated antigen 4 (CTLA4), LPS-responsive and beige-like anchor protein (LRBA), and BTB domain and CNC homolog 2 (BACH2) and gain-of-function mutations in signal transducer and activator of transcription 3 (STAT3). We also discuss deficiencies in genes encoding STAT5b and IL-10 or IL-10 receptor as potential Tregopathies.

Porous scaffolds from droplet microfluidics for prevention of intrauterine adhesion

Severe intrauterine adhesions (IUAs) have a great negative impact on women's psychological and reproductive health. It remains a significant challenge to prevent postoperative IUAs because of the complications of various clinical preventive measures and incompatibility of uterine cavity morphology. Herein, we present a new drug-loadedporous scaffold based on a microfluidic droplet template, which combines the characteristics of the artificial biocompatible material GelMA and the natural polysaccharide material Na-alginate. By changing the containers that collect the microfluidic droplets, the porous scaffold conforming to the shape of the uterine cavity could be obtained. The porous structure, mechanical property, and flexibility impart the scaffold with compressibility and send it to the uterus through the vagina. In addition, the external-internal connected open structures could load and control the release of drugs to repair the damaged region continuously in vivo. To verify the antiadhesion and repair of drug-loaded porous scaffolds, we tested the system in the rat model of IUAs, and it was demonstrated that the system had the ability to improve neovascularization, cellularize the damaged tissue, and repair the endometrium. These features provide the drug-loaded porous scaffolds with new options for the improvement of postoperative IUAs. STATEMENT OF SIGNIFICANCE: Intrauterine adhesions are caused by various causes of damage to the endometrial basal layer, thus leading to part or entire adhesions in the cervical or uterine cavity. Clinically, various preventive measures reach the barrier effect through the physical barrier, which are difficult to further promote the repair of the damaged endometrium, and most of them have apparent side effects. This study aims to prepare compressible and biodegradable three-dimensional porous drug-loading biological scaffolds. GelMA and Na-alginate have desirable biocompatibility. The interconnect porous scaffolds, which were prepared through the combination of biomaterials and single emulsion microfluidics, not only have compressibility but also provide space for drug delivery and release. This system can further promote the repair of the endometrium while preventing adhesion.

Immune Dysregulation, Polyendocrinopathy, Enteropathy, X-Linked Syndrome Associated With a Novel Mutation of FOXP3 Gene

The immune dysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX) syndrome is a rare, x-linked, recessive disorder characterized by dysfunction of the T regulatory (Treg) lymphocytes leading to autoimmune diseases. Herein we report a male patient with IPEX syndrome who presented with severe diarrhea, eczema, and malabsorption leading to failure to thrive and necessitating total parenteral nutrition, as well as with liver dysfunction. Laboratory investigation showed elevated liver enzymes that declined following treatment with glucocorticosteroids and immunosuppressive drugs, marked eosinophilia, increased total IgE, and decreased Treg cells. DNA analysis revealed that the patient himself was hemizygous and his mother heterozygous for the exon 10, c.1015C>T (p.Pro339Ser) mutation of the FOXP3 gene, which has not been previously reported. The current case indicates that mutations resulting in substitution of a certain amino-acid (i.e., proline 339) by different amino-acids are manifested with different IPEX phenotypes.

Clinical Heterogeneity of Immune Dysregulation, Polyendocrinopathy, Enteropathy, X-Linked Syndrome: A French Multicenter Retrospective Study

Objective

Immune dysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX) syndrome is an autoimmune disease caused by mutations in the forkhead box protein 3 gene (FOXP3), which encodes a key regulator of immune tolerance. The aim of this study was to describe the clinical heterogeneity of the disease in a national French cohort.

Methods

Multicenter retrospective study of patients diagnosed with IPEX syndrome caused by mutations in FOXP3.

Results

Thirty children from 26 families were included. Age at disease onset (median [first to third quartile]) was 1.5 mo [0–84] and at death 3.5 years [0–10.5] (n = 15) indicating a high heterogeneity. Initial presentation was diarrhoea (68%), type 1 diabetes (T1D; 25%), skin lesions (7%) and nephropathy (3%). During the course of the disease the following main symptoms were observed: diarrhoea (100%), skin lesions (85%), T1DM (50%), severe food allergies (39%), haematological disorders (28%), nephropathies (25%), hepatitis (14%) as well as the presence of a variety of autoantibodies. Immunosuppressive mono- or combination therapy led to improvement in eight children. Three boys displayed a stable disease course without any immunosuppressive medication. Overall 10-year survival rate was 43% (42% in transplanted patients and 52% in patients on immunosuppressive therapy). Five out of 22 identified FOXP3 mutations have not been described yet: c.−23 + 1G > A, c.−23 + 5G > A, c.264delC, c.1015C > T and c.1091A > G. The first two produced atypical, attenuated phenotypes. Missense and frameshift mutations affecting the forkhead domain were associated with poor survival (Gehan–Wilcoxon p = 0.002).

Conclusion

The broad phenotypic heterogeneity of IPEX raises questions about modifying factors and justifies early FOXP3 sequencing in suspected cases.

Persistent Enteropathy in a Toddler with a Novel FOXP3 Mutation and Normal FOXP3 Protein Expression

Immune dysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX) syndrome is caused by mutations in the FOXP3 gene. Patients usually present with a clinical triad of intractable diarrhea, diabetes, and eczema. In this patient, FOXP3 protein expression was normal, but FOXP3 Sanger sequencing confirmed the clinical suspicion of IPEX by detecting a previously unreported missense variant. Early recognition of IPEX is important, because hematopoietic stem cell transplantation can be curative.

Meat and Nicotinamide: A Causal Role in Human Evolution, History, and Demographics

Hunting for meat was a critical step in all animal and human evolution. A key brain-trophic element in meat is vitamin B3 / nicotinamide. The supply of meat and nicotinamide steadily increased from the Cambrian origin of animal predators ratcheting ever larger brains. This culminated in the 3-million-year evolution of Homo sapiens and our overall demographic success. We view human evolution, recent history, and agricultural and demographic transitions in the light of meat and nicotinamide intake. A biochemical and immunological switch is highlighted that affects fertility in the 'de novo' tryptophan-to-kynurenine-nicotinamide 'immune tolerance' pathway. Longevity relates to nicotinamide adenine dinucleotide consumer pathways. High meat intake correlates with moderate fertility, high intelligence, good health, and longevity with consequent population stability, whereas low meat/high cereal intake (short of starvation) correlates with high fertility, disease, and population booms and busts. Too high a meat intake and fertility falls below replacement levels. Reducing variances in meat consumption might help stabilise population growth and improve human capital.

Novel pathogenic variants in FOXP3 in fetuses with echogenic bowel and skin desquamation identified by ultrasound

Immunodysregulation, Polyendocrinopathy, Enteropathy, X-linked (IPEX) syndrome is a rare, X-linked recessive disease that affects regulatory T cells (Tregs) resulting in diarrhea, enteropathy, eczema, and insulin-dependent diabetes mellitus. IPEX syndrome is caused by pathogenic alterations in FOXP3 located at Xp11.23. FOXP3 encodes a transcription factor that interacts with several partners, including NFAT and NF-κB, and is necessary for the proper cellular differentiation of Tregs. Although variable, the vast majority of IPEX syndrome patients have onset of disease during infancy with severe enteropathy. Only five families with prenatal presentation of IPEX syndrome have been reported. Here, we present two additional prenatal onset cases with novel inherited frameshift pathogenic variants in FOXP3 that generate premature stop codons. Ultrasound findings in the first patient identified echogenic bowel, echogenic debris, scalp edema, and hydrops. In the second patient, ultrasound findings included polyhydramnios with echogenic debris, prominent fluid-filled loops of bowel, and echogenic bowel. These cases further broaden the phenotypic spectrum of IPEX syndrome by describing previously unappreciated prenatal ultrasound findings associated with the disease.