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.

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.

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.

Gray Zone Lymphoma Arising in the Neck of a Teenager With a Germline Mutation in TP53.

Gray zone lymphoma is an aggressive disease for which appropriate management is still debated. We report a 15-year-old girl with a cervical mass, an enlarged ipsilateral tonsil, and anemia. Both sites showed hypermetabolism on F18-FG positron emission tomography/CT. Surgical resection was diagnostic of Epstein-Barr virus-negative gray zone lymphoma cervical and tonsillar involvement. No abnormality was found in cytogenetic analysis on tumor cells. However, exome sequencing in peripheral blood DNA revealed a germline mutation in TP53. Complete response was achieved after surgery and 6 cycles of rituximab with dose-adjusted etoposide, prednisone, vincristine, cyclophosphamide, and doxorubicin regimen.

A Case Report of Syndromic Multinodular Goitre in Adolescence: Exploring the Phenotype Overlap between Cowden and DICER1 Syndromes.

BACKGROUND: Hereditary tumour predisposition syndromes may increase the risk for development of thyroid nodules at a young age. We present the case of an adolescent female with Cowden syndrome who had some atypical phenotypic features which overlapped with the DICER1 syndrome. MATERIAL AND METHODS: A 17-year-old female presented with a 3-month history of progressive right neck swelling. Fine needle cytology of the thyroid revealed a follicular neoplasm with features suggestive of follicular variant of papillary thyroid carcinoma and she underwent a hemithyroidectomy. Enlarging nodules in the remaining thyroid led to a completion thyroidectomy at 19 years of age. The patient's past medical history included an ovarian mixed malignant germ cell tumour, pulmonary nodules and cysts, renal cysts, mucocutaneous lesions, an arachnoid cyst, and a fibrous breast lesion. Macrocephaly was noted on physical examination. RESULTS: Based on the patient's complex phenotype and young age, a hereditary predisposition syndrome was suspected and genetic testing of PTEN and DICER1 was undertaken. A heterozygous truncating germ-line PTEN mutation was identified, which combined with clinical findings, met criteria for the diagnosis of Cowden syndrome. Additional loss of heterozygosity of the wild-type PTEN allele was detected in the right thyroid lesion and ovarian tumour. No DICER1 mutations were identified. CONCLUSIONS: Genetic testing was crucial in elucidating this patient's predisposition to the early development of neoplastic and non-neoplastic conditions. Our report also highlights the phenotypic overlap between the Cowden and DICER1 syndromes and illustrates the importance of recognising the variable phenotypic features of hereditary syndromes in order to enable timely implementation of appropriate care.

Multiple DICER1-related tumors in a child with a large interstitial 14q32 deletion.

Germ-line interstitial deletions involving the 14q32 chromosomal region, resulting in 14q32 deletion syndrome, are rare. DICER1 is a recently described cancer-predisposition gene located at 14q32.13. We report the case of a male child with a ∼5.8 Mbp 14q32.13q32.2 germ-line deletion, which included the full DICER1 locus. We reviewed available clinical and pathological material, and conducted genetic analyses. In addition to having congenital dysmorphic features, the child developed multiple DICER1 syndrome-related tumors before age 5 y: a pediatric cystic nephroma (pCN), a ciliary body medulloepithelioma (CBME), and a small lung cyst (consistent with occult pleuropulmonary blastoma Type I/Ir cysts seen in DICER1 mutation carriers). He also developed a cerebral spindle-cell sarcoma with myogenous differentiation. Our investigations revealed that the deletion encompassed 31 protein-coding genes. In addition to the germ-line DICER1 deletion, somatic DICER1 RNase IIIb mutations were found in the CBME (c.5437G > A, p.E1813K), pCN (c.5425G > A, p.G1809R), and sarcoma (c.5125G > A, p.D1709N). The sarcoma also harbored a somatic TP53 mutation: c.844C > T, p.R282W. Additional copy number alterations were identified in the CBME and sarcoma using an OncoScan array. Among the 8 cases with molecularly-defined 14q32 deletions involving DICER1 and for whom phenotypic information is available, our patient and one other developed DICER1-related tumors. Biallelic DICER1 mutations have not previously been reported to cause cerebral sarcoma, which now may be considered a rare manifestation of the DICER1 syndrome. Our study shows that DICER1-related tumors can occur in children with 14q32 deletions and suggests surveillance for such tumors may be warranted.

Genomic study of severe fetal anomalies and discovery of GREB1L mutations in renal agenesis.

PURPOSE: Fetal anomalies represent a poorly studied group of developmental disorders. Our objective was to assess the impact of whole-exome sequencing (WES) on the investigation of these anomalies. METHODS: We performed WES in 101 fetuses or stillborns who presented prenatally with severe anomalies, including renal a/dysgenesis, VACTERL association (vertebral defects, anal atresia, cardiac defects, tracheoesophageal fistula, renal anomalies, and limb abnormalities), brain anomalies, suspected ciliopathies, multiple major malformations, and akinesia. RESULTS: A molecular diagnosis was obtained in 19 cases (19%). In 13 of these cases, the diagnosis was not initially suspected by the clinicians because the phenotype was nonspecific or atypical, corresponding in some cases to the severe end of the spectrum of a known disease (e.g., MNX1-, RYR1-, or TUBB-related disorders). In addition, we identified likely pathogenic variants in genes (DSTYK, ACTB, and HIVEP2) previously associated with phenotypes that were substantially different from those found in our cases. Finally, we identified variants in novel candidate genes that were associated with perinatal lethality, including de novo mutations in GREB1L in two cases with bilateral renal agenesis, which represents a significant enrichment of such mutations in our cohort. CONCLUSION: Our study opens a window on the distinctive genetic landscape associated with fetal anomalies and highlights the power-but also the challenges-of WES in prenatal diagnosis.

A case of neuroblastoma in DICER1 syndrome: Chance finding or noncanonical causation?

DICER1 syndrome is an inherited disorder associated with at least a dozen rare, mainly pediatric-onset tumors. Its characterization remains incomplete. Some studies suggested that neuroblastoma (NB) may be involved in this syndrome. Here, we describe the case of a 14-year-old female presenting with a multinodular goiter (MNG) and a collision tumor composed of NB and cystic nephroma (CN). She is a carrier of a deleterious germline mutation in exon 23 of DICER1 and harbored different somatic mutations in the CN and MNG. However, no second hit was found in the NB, questioning its status as a DICER1-related tumor.

Sequencing of DICER1 in sarcomas identifies biallelic somatic DICER1 mutations in an adult-onset embryonal rhabdomyosarcoma.

BACKGROUND: Sarcomas are rare and heterogeneous cancers. We assessed the contribution of DICER1 mutations to sarcoma development. METHODS: The coding region of DICER1 was sequenced in 67 sarcomas using a custom Fluidigm Access Array. The RNase III domains were Sanger sequenced in six additional sarcomas to identify hotspot DICER1 variants. RESULTS: The median age of sarcoma diagnosis was 45.7 years (range: 3 months to 87.4 years). A recurrent embryonal rhabdomyosarcoma (ERMS) of the broad ligament, first diagnosed at age 23 years, harboured biallelic pathogenic somatic DICER1 variants (1 truncating and 1 RNase IIIb missense). We identified nine other DICER1 variants. One somatic variant (p.L1070V) identified in a pleomorphic sarcoma and one germline variant (c.2257-7A>G) may be pathogenic, but the others are considered to be benign. CONCLUSIONS: We show that deleterious DICER1 mutations underlie the genetic basis of only a small fraction of sarcomas, in particular ERMS of the urogenital tract.