Predictive biomarkers and initial analysis of maternal immune alterations in postpartum preeclampsia reveal an immune-driven pathology.

Introduction: Postpartum preeclampsia (PPPE) is an under-diagnosed condition, developing within 48 hours to 6 weeks following an uncomplicated pregnancy. The etiology of PPPE is still unknown, leaving patients vulnerable and making the identification and treatment of patients requiring postpartum care an unmet need. We aimed to understand the immune contribution to PPPE at the time of diagnosis, as well as uncover the predictive potential of perinatal biomarkers for the early postnatal identification of high-risk patients. Methods: Placentas were collected at delivery from uncomplicated pregnancies (CTL) and PPPE patients for immunohistochemistry analysis. In this initial study, blood samples in PPPE patients were collected at the time of PPPE diagnosis (48h-25 days postpartum; mean 7.4 days) and compared to CTL blood samples taken 24h after delivery. Single-cell transcriptomics, flow cytometry, intracellular cytokine staining, and the circulating levels of inflammatory mediators were evaluated in the blood. Results: Placental CD163+ cells and 1st trimester blood pressures can be valuable non-invasive and predictive biomarkers of PPPE with strong clinical application prospects. Furthermore, changes in immune cell populations, as well as cytokine production by CD14+, CD4+, and CD8+ cells, suggested a dampened response with an exhausted phenotype including decreased IL1ß, IL12, and IFNγ as well as elevated IL10. Discussion: Understanding maternal immune changes at the time of diagnosis and prenatally within the placenta in our sizable cohort will serve as groundwork for pre-clinical and clinical research, as well as guiding clinical practice for example in the development of immune-targeted therapies, and early postnatal identification of patients who would benefit from more thorough follow-ups and risk education in the weeks following an uncomplicated pregnancy.

Placenta analysis of Hofbauer cell profile according to the class of antiretroviral therapy used during pregnancy in people living with HIV.

INTRODUCTION: The use of antiretroviral therapy drastically reduces vertical transmission of Human Immunodeficiency Virus. However, recent studies demonstrate associations between ART use during pregnancy and placental inflammation, particularly within protease inhibitor (PI)-based regimens. We sought to characterize placental macrophages, namely Hofbauer cells, according to the class of ART used during pregnancy. METHODS: Using immunofluorescence and immunohistochemistry, placentas from 79 pregnant people living with HIV (PPLWH) and 29 HIV-uninfected people were analyzed to quantify the numbers and frequencies of leukocytes (CD45+) and Hofbauer cells (CD68+ and/or CD163+). PPLWH were stratified into three groups based on class of ART: non-nucleoside reverse transcriptase inhibitor (NNRTI)-based, integrase strand-transfer inhibitor (INSTI)-based, and PI-based regimens. RESULTS: Placentas of PPLWH contained significantly more leukocytes and Hofbauer cells than controls. Multivariable analyses revealed that this increase in immune cells was associated with a predominantly CD163+ profile in all ART subgroups compared to the HIV-negative group. This was characterized by an increase in total CD163+ cells in the PI and INSTI subgroups, and a higher frequency of CD163+ cells and CD163+/CD68+ ratio in the NNRTI and PI subgroups. DISCUSSION: Placentas of PPLWH treated with any ART regimen during their entire pregnancy displayed a selection for CD163+ cells compared to the HIV-negative group, regardless of class of ART, suggesting that class of ART does not intrinsically affect selection of CD163+ and CD68+ Hofbauer cells. Further investigations into the role of Hofbauer cells in ART-associated placental inflammation are warranted to identify the mechanisms behind their potential involvement in maternal-fetal tolerance maintenance.

Phenotype and outcomes of very early onset and early onset inflammatory bowel diseases in a Montreal pediatric cohort.

Objectives: The incidence of very-early-onset inflammatory bowel disease (VEO-IBD) and early-onset IBD (EO-IBD) is increasing. Here, we report their phenotype and outcomes in a Montreal pediatric cohort. Methods: We analyzed data from patients diagnosed with IBD between January 2014 and December 2018 from the CHU Sainte-Justine. The primary endpoint was to compare the phenotypes of VEO-IBD and EO-IBD. The secondary endpoints involved comparing outcomes and rates of steroid-free clinical remission (SFCR) at 12 (±2) months (m) post-diagnosis and at last follow-up. Results: 28 (14 males) and 67 (34 males) patients were diagnosed with VEO-IBD and EO-IBD, respectively. Crohn's disease (CD) was more prevalent in EO-IBD (64.2% vs. 39.3%), whereas unclassified colitis (IBD-U) was diagnosed in 28.6% of VEO-IBD vs. 10.4% of EO-IBD (p < 0.03). Ulcerative colitis (UC) and IBD-U predominantly presented as pancolitis in both groups (VEO-IBD: 76.5% vs. EO-IBD: 70.8%). Combining all disease subtypes, histological upper GI lesions were found in 57.2% of VEO-IBD vs. 83.6% of EO-IBD (p < 0.009). In each subtype, no differential histological signature (activity, eosinophils, apoptotic bodies, granulomas) was observed between both groups. At 12 m post-diagnosis, 60.8% of VEO-IBD and 62.7% of EO-IBD patients were in SFCR. At a median follow-up of 56 m, SFCR was observed in 85.7% of VEO-IBD vs. 85.0% of EO-IBD patients. Conclusion: The rate of patients in SFCR at 1-year post-diagnosis and at the end of follow-up did not significantly differ between both groups.

Evaluation of a clinical protocol for the management of fever in labor among pregnant women at term: A quality-improvement study.

OBJECTIVE: To assess the impact of a quality-improvement initiative designed to increase diagnostic accuracy and adequate management of clinical chorioamnionitis (CC) at a tertiary center. Chorioamnionitis occurs in 1%-13% of term pregnancies and increases maternal and neonatal peripartum complications; often over-diagnosed, it leads to unnecessary investigations and treatments. METHODS: This was an interrupted time-series study. In September 2017 two interventions were implemented: (1) staff training and (2) standardized clinical protocol for the management of fever in labor. All singleton term pregnancies were included. CC cases were reviewed in the pre-intervention (2015-2016, n = 179) and post-intervention (2017-2018, n = 142) groups. CC criteria based on the American College of Obstetricians and Gynecologists guidelines, antibiotics, maternal and neonatal outcomes, and pathology were compared. A cost-consequence analysis was performed. RESULTS: Incidence of CC decreased from 8.2 to 5.6 per 10 person-year (P < 0.001). This was associated with a significant increase in diagnostic accuracy from 15.7% to 73.2% (P < 0.001). Weight-adjusted tobramycin dosage improved from 8.8% to 69.1% (P < 0.001). Maternal length of hospitalization and readmissions decreased significantly, without affecting neonatal sepsis rate. Interventions decreased yearly hospital costs associated with CC by 23.4%. CONCLUSION: Standardizing the management of fever in labor significantly increased the diagnostic accuracy of CC and decreased the misuse of antibiotics in term pregnancies. CC costs decreased by 23.4%.

ß Cell mass expansion during puberty involves serotonin signaling and determines glucose homeostasis in adulthood.

Puberty is associated with transient insulin resistance that normally recedes at the end of puberty; however, in overweight children, insulin resistance persists, leading to an increased risk of type 2 diabetes. The mechanisms whereby pancreatic ß cells adapt to pubertal insulin resistance, and how they are affected by the metabolic status, have not been investigated. Here, we show that puberty is associated with a transient increase in ß cell proliferation in rats and humans of both sexes. In rats, ß cell proliferation correlated with a rise in growth hormone (GH) levels. Serum from pubertal rats and humans promoted ß cell proliferation, suggesting the implication of a circulating factor. In pubertal rat islets, expression of genes of the GH/serotonin (5-hydroxytryptamine [5-HT]) pathway underwent changes consistent with a proliferative effect. Inhibition of the pro-proliferative 5-HT receptor isoform HTR2B blocked the increase in ß cell proliferation in pubertal islets ex vivo and in vivo. Peripubertal metabolic stress blunted ß cell proliferation during puberty and led to altered glucose homeostasis later in life. This study identifies a role of GH/GH receptor/5-HT/HTR2B signaling in the control of ß cell mass expansion during puberty and identifies a mechanistic link between pubertal obesity and the risk of developing type 2 diabetes.

Autologous humanized mouse models of iPSC-derived tumors enable characterization and modulation of cancer-immune cell interactions.

Modeling the tumor-immune cell interactions in humanized mice is complex and limits drug development. Here, we generated easily accessible tumor models by transforming either primary skin fibroblasts or induced pluripotent stem cell-derived cell lines injected in immune-deficient mice reconstituted with human autologous immune cells. Our results showed that fibroblastic, hepatic, or neural tumors were all efficiently infiltrated and partially or totally rejected by autologous immune cells in humanized mice. Characterization of tumor-immune infiltrates revealed high expression levels of the dysfunction markers Tim3 and PD-1 in T cells and an enrichment in regulatory T cells, suggesting rapid establishment of immunomodulatory phenotypes. Inhibition of PD-1 by Nivolumab in humanized mice resulted in increased immune cell infiltration and a slight decrease in tumor growth. We expect that these versatile and accessible cancer models will facilitate preclinical studies and the evaluation of autologous cancer immunotherapies across a range of different tumor cell types.

Risk Factors of Clinical Relapses in Pediatric Luminal Crohn's Disease: A Retrospective Cohort Study.

INTRODUCTION: There is currently little knowledge on factors associated with the relapse of Crohn's disease (CD) in children. The aims of this study were to describe the risk factors associated with relapse in pediatric CD and the changes in the relapse rate over the past decade. METHODS: Patients younger than 18 years and diagnosed between 2009 and 2019 were included in this retrospective cohort study. Clinical, endoscopic, histological, and laboratory data, as well as induction and maintenance treatments, were collected from the medical records. Survival analyses and Cox regression models were used to assess the impact of these risk factors on relapse. RESULTS: Six hundred thirty-nine patients were included. There was a decrease in the clinical relapse rate over the past decade: 70.9% of the patients diagnosed between 2009 and 2014 relapsed as compared with 49.1% of the patients diagnosed between 2015 and 2019 (P < 0.0001). The following variables were associated with clinical relapse: female sex (adjusted hazard ratio [aHR] = 1.52, P = 0.0007), exposure to oral 5-ASA (aHR = 1.44, P = 0.04), use of immunomodulatory agents compared with tumor necrosis factor-alpha inhibitors (methotrexate aHR = 1.73, P = 0.003; thiopurines aHR = 1.63, P = 0.002), presence of granulomas (aHR = 1.34, P = 0.02) and increased eosinophils on intestinal biopsies (aHR = 1.36, P = 0.02), high levels of C-reactive protein (aHR = 1.01, P < 0.0001) and fecal calprotectin (aHR = 1.08, P < 0.0001), and low serum infliximab levels (aHR = 2.32, P = 0.001). DISCUSSION: Relapse of pediatric CD has decreased in the past decade. The risk of relapse is significantly associated with clinical, endoscopic, histological, and laboratory variables and treatment strategies.

Changes in the clinical phenotype and behavior of pediatric luminal Crohn's disease at diagnosis in the last decade.

BACKGROUND AND AIMS: The aims of this study were to describe the trends in the behavior of pediatric CD during the last decade and to describe the seasonal variation of disease presentation. METHODS: Patients under 18 years old and diagnosed between 2009 and 2019 were included. The clinical, endoscopic, histological, and laboratory data were collected from the medical records. We analyzed the trends of these parameters according to the year and season of diagnosis. RESULTS: 654 patients were included in the study. The number of incident CD cases increased yearly. Patients diagnosed between 2015 and 2019 were younger at diagnosis (OR 2.53, p = 0.02), had more perianal diseases (OR: 2.30, p < 0.0001) and more granulomas (OR: 1.61, p = 0.003), but fewer eosinophils (OR: 0.35, p < 0.0001) and less chronic lymphoplasmacytic infiltrate (OR: 0.56, p = 0.008) as compared to the 2009-2014 cohort. There was fewer CD diagnosis during winter. Patients diagnosed in the fall had lower PCDAIs, less failure to thrive and less extensive digestive involvement. Colonic disease was significantly more frequent during summer and fall. CONCLUSION: The clinical and histological phenotype of CD has changed over time and there are important seasonal trends in the frequency and severity on disease behavior suggesting possible disease triggers.

Characterization of the Transition Zone in Short Segment Hirschsprung Disease Using Calretinin Immunostaining.

Introduction: The detailed expression pattern of calretinin immunohistochemistry in the transition zone (TZ) of Hirschsprung disease (HSCR) has not yet been reported. This study aims to examine the value of calretinin immunohistochemistry for more accurately determining the distal and proximal border of the TZ in short segment HSCR. Methods: Specimens of pull-through surgery from 51 patients with short form of HSCR were analyzed on two longitudinal strips using hematoxylin and eosin (H&E) staining and calretinin immunohistochemistry. Results: In all but two patients, the first appearance of calretinin expression was seen on mucosal nerve fibers before the appearance of any ganglion cells, indicating the distal border of the TZ. The maximum distance between the distal border of the TZ and the proximal border of the TZ, defined by ganglion cells in a normal density on H&E stained sections, a strong calretinin expression on mucosal nerve fibers and in >80% of submucosal and myenteric ganglion cells, with no nerve hypertrophy and absence of ganglionitis was 60 mm. Conclusion: The distal border of the TZ is characterized by calretinin positive intramucosal neurites in nearly all of short form of HSCR and not by calretinin expression on ganglion cells.

Factors associated with time to clinical remission in pediatric luminal Crohn's disease: A retrospective cohort study.

BACKGROUND AND AIM: Data on factors influencing time to remission in pediatric Crohn's disease (CD) are very limited in the literature. The aim of this retrospective cohort study was to describe the trends of time to clinical remission over the past decade and to identify factors associated with time to clinical remission in children with luminal CD. METHODS: Patients under 18 years old diagnosed between 2009 and 2019 were included. All data were collected from the patients' medical records. Survival analyses and linear regression models were used to assess the impact of clinical, laboratory, endoscopic, histological, and therapeutic factors on time to clinical remission. RESULTS: A total of 654 patients were included in the study. There was no change in the time to clinical remission over the decade. Female sex in adolescents (adjusted bêta regression coefficient [aß] = 31.8 days, P = 0.02), upper digestive tract involvement (aß = 46.4 days, P = 0.04) perianal disease (aß = 32.2 days, P = 0.04), presence of active inflammation on biopsies at diagnosis (aß = 46.7 days, P = 0.01) and oral 5-aminosalicylates (5-ASA) exposure (aß = 56.6 days, P = 0.002) were associated with longer time to clinical remission. Antibiotic exposure (aß = -29.3 days, P = 0.04), increased eosinophils (aß = -29.6 days, P = 0.008) and combination of exclusive enteral nutrition with tumor-necrosis-factor-alpha (TNF-alpha) inhibitors as induction therapy (aß = -36.8 days, P = 0.04) were associated with shorter time to clinical remission. CONCLUSION: In children with newly diagnosed Crohn's disease, time to clinical remission did not shorten during the decade. It was associated with baseline clinical and histological data and treatment strategies. Combination of enteral nutrition and TNF-alpha inhibitors was associated with faster clinical remission.

Association between proteinuria and placental pathology in preeclampsia: A retrospective study.

INTRODUCTION: Preeclampsia develops due to placental insufficiency and systemic proinflammatory and antiangiogenic mediator release, with ensuing systemic endothelial dysfunction. Nephrotic-range proteinuria appears to be associated with worse pregnancy outcomes. The relationship between differing degrees of proteinuria and the severity of placental alterations has not been studied. METHODS: This is a single-centre retrospective comparison of 150 singleton pregnancies complicated by preeclampsia and varying degrees of proteinuria. Maternal demographic, obstetrical and fetal outcome data were obtained from chart review. The placental histologic evaluations were performed by a placental pathologist blinded to all other clinical information. RESULTS: Preeclamptic women with massive proteinuria had evidence of more severe maternal vascular malperfusion lesions. The severity of the lesions was progressive through mild, moderate and massive proteinuria. Women with massive proteinuria had a higher incidence of renal dysfunction and severe hypertension, and had earlier preterm deliveries compared to preeclamptic women with mild and moderate proteinuria (p < 0.05). CONCLUSION: Preeclampsia with more severe proteinuria is associated with a higher prevalence of placental maternal vascular malperfusion.

Pandemic stress and SARS-CoV-2 infection are associated with pathological changes at the maternal-fetal interface.

INTRODUCTION: The reported effects of SARS-CoV-2 on pregnancy outcomes are conflicting; studies frequently overlook the placenta, which is critical for the health of the mother and infant(s). This study aimed to determine the effect of pandemic stress ± SARS CoV-2 infection on placental histopathology. METHODS: Women were recruited in Canada (n = 69); France (n = 21) or in the UK (n = 25), between March and October 2020. Historic controls (N = 20) were also included. Placenta and fetal membrane samples were collected rapidly after delivery and were fixed and stained for histopathological analysis. Maternal demographical data and obstetric outcomes were recorded. RESULTS: Over 80% of the placentas from SARS-CoV-2+ pregnancies had histopathological abnormalities: predominantly structural (71-86%) or inflammatory (9-22%), depending on geographical location. Excessive fibrin was seen in all sites, whereas deciduitis (Canada), calcifications (UK), agglutinations and chorangiosis (France) predominated in different locations. The frequency of abnormalities was significantly higher than in SARS-CoV-2 negative women (50%, p < 0.05). Demographic and obstetric data were similar in the SARS-CoV-2+ women across all sites - characterised by predominantly Black/Middle Eastern women, and women with elevated body mass index. DISCUSSION: Overall, the frequency of placental abnormalities is increased in SARS-CoV-2+ women, but the incidence of placental abnormalities is also higher in SARS-CoV-2- women that gave birth during the pandemic, which highlights the importance of appropriate control groups to ascertain the roles of pandemic stress and SARS-CoV-2 infection on the placenta and pregnancy outcomes.

Mesenchymal Hamartoma of the Liver and DICER1 Syndrome.

Mesenchymal hamartoma of the liver (MHL) is a benign tumor affecting children that is characterized by a primitive myxoid stroma with cystically dilated bile ducts. Alterations involving chromosome 19q13 are a recurrent underlying cause of MHL; these alterations activate the chromosome 19 microRNA cluster (C19MC). Other cases remain unexplained. We describe two children with MHLs that harbored germline DICER1 pathogenic variants. Analysis of tumor tissue from one of the children revealed two DICER1 "hits." Mutations in DICER1 dysregulate microRNAs, mimicking the effect of the activation of C19MC. Our data suggest that MHL is a new phenotype of DICER1 syndrome. (Funded by the Canadian Institutes of Health Research and others.).

Molecular Profiling of Hard-to-Treat Childhood and Adolescent Cancers.

Importance: Little progress in pediatric cancer treatment has been noted in the past decade, urging the development of novel therapeutic strategies for adolescents and children with hard-to-treat cancers. Use of comprehensive molecular profiling in the clinical management of children and adolescents with cancer appears a suitable approach to improve patient care and outcomes, particularly for hard-to-treat cases. Objective: To assess the feasibility of identifying potentially actionable mutations using next-generation sequencing-based assays in a clinically relevant time frame. Design, Setting, and Participants: This diagnostic study reports the results of the TRICEPS study, a prospective genome sequencing study conducted in Québec, Canada. Participants, aged 18 years or younger at diagnosis, with refractory or relapsed childhood and adolescent cancers were enrolled from April 2014 through January 2018. Whole-exome sequencing (WES) of matched tumor normal samples and RNA sequencing of tumor were performed to identify single-nucleotide variants, fusion transcripts, differential gene expression, and copy number alterations. Results reviewed by a team of experts were further annotated, synthesized into a report, and subsequently discussed in a multidisciplinary molecular tumor board. Main Outcomes and Measures: Molecular profiling of pediatric patients with hard-to-treat cancer, identification of actionable and targetable alteration needed for the management of these patients, and proposition of targeted and personalized novel therapeutic strategies. Results: A total of 84 patients with hard-to-treat cancers were included in the analysis. These patients had a mean (range) age of 10.1 (1-21) years and a similar proportion of male (45 [54%]) and female (39 [46%]). Sixty-two patients (74%) had suitable tissues for multimodal molecular profiling (WES and RNA sequencing). The process from DNA or RNA isolation to genomic sequencing and data analysis steps took a median (range) of 24 (4-41) days. Potentially actionable alterations were identified in 54 of 62 patients (87%). Actions were taken in 22 of 54 patients (41%), and 18 (33%) either were on a second or third line of treatment, were in remission, or had stable disease and thus no actions were taken. Conclusions and Relevance: Incorporating genomic sequencing into the management of hard-to-treat childhood and adolescent cancers appeared feasible; molecular profiling may enable the identification of potentially actionable alterations with clinical implications for most patients, including targeted therapy and clinically relevant information of diagnostic, prognostic, and monitoring significance.