Pathways and microbiome modifications related to surgery and enterocolitis in Hirschsprung disease.

BACKGROUND: Hirschsprung disease (HSCR) is a congenital anomaly of the enteric nervous system. Abnormal microbiome composition was reported in HSCR patients. In this study, we addressed and analyzed microbiome modifications with relation tosurgery and HSCR associated enterocolitis (HAEC). METHODS: The faecal microbiome of 31 HSCR patients (overall 64 samples) was analyzed. HAEC was diagnosed and classified according to a combination of Pastor's and Elhalabi's criteria. Stool samples were analyzed by 16S sequencing (7 out of 9 polymorphic regions). Compositional and relative abundance profiles, as well as the functional potentials of the microbial community, were analyzed with the marker gene sequencing profiles using PICRUSt. RESULTS: The relative abundance of Bacteroidetes showed a severe decrease with slow recovery after surgery. Conversely, Proteobacteria transiently increased their abundance. Noteworthy, a strong linkage has been found between Proteobacteria descendants and HAEC occurrences. The inferred functional analysis indicated that virulence factors and fimbriae or pili might be associated with HAEC. CONCLUSIONS: Our study, addressing microbiome dynamics, demonstrated relevant changes after surgical manipulation. Alpha-diversity analyses indicated that surgery deeply affects microbiome composition. Proteobacteria and Enterobacteriaceae seem to play a pivotal role in HAEC occurrences. Several virulence factors, such as fimbriae or pili, might explain the HAEC-predisposing potential of selected microbiomes. These results suggest some innovative therapeutic approaches that deserve to be tested in appropriate clinical trials.

The OSMR Gene Is Involved in Hirschsprung Associated Enterocolitis Susceptibility through an Altered Downstream Signaling.

Hirschsprung (HSCR) Associated Enterocolitis (HAEC) is a common life-threatening complication in HSCR. HAEC is suggested to be due to a loss of gut homeostasis caused by impairment of immune system, barrier defense, and microbiome, likely related to genetic causes. No gene has been claimed to contribute to HAEC occurrence, yet. Genetic investigation of HAEC by Whole-Exome Sequencing (WES) on 24 HSCR patients affected (HAEC) or not affected (HSCR-only) by enterocolitis and replication of results on a larger panel of patients allowed the identification of the HAEC susceptibility variant p.H187Q in the Oncostatin-M receptor (OSMR) gene (14.6% in HAEC and 5.1% in HSCR-only, p = 0.0024). Proteomic analysis on the lymphoblastoid cell lines from one HAEC patient homozygote for this variant and one HAEC patient not carrying the variant revealed two well distinct clusters of proteins significantly up or downregulated upon OSM stimulation. A marked enrichment in immune response pathways (q < 0.0001) was shown in the HAEC H187 cell line, while proteins upregulated in the HAEC Q187 lymphoblasts sustained pathways likely involved in pathogen infection and inflammation. In conclusion, OSMR p.H187Q is an HAEC susceptibility variant and perturbates the downstream signaling cascade necessary for the gut immune response and homeostasis maintenance.

Chronic intestinal pseudo-obstruction in a child harboring a founder Hirschsprung RET mutation.

Chronic intestinal pseudo obstruction (CIPO) is a rare clinical entity characterized by symptoms and signs of intestinal obstruction without either recognizable anatomical abnormalities or intestinal aganglionosis. A Chinese female infant presented to our institution with a clinical diagnosis of CIPO. Aganglionosis was ruled out by full thickness colonic and ileal biopsies and by rectal suction biopsies. Unexpectedly, direct sequencing and PCR amplification of RET proto-oncogene from peripheral blood extracted DNA identified a RET R114H mutation. This mutation has already been reported as strongly associated with Asian patients affected by Hirschsprung's disease (HSCR) and is considered a founder mutation in Asia. The same mutation has never been reported in patients with CIPO, so far. These findings support the role of RET in the development of the enteric nervous system but underline the importance of other genetic or environmental factors contributing to the gastrointestinal phenotype of the disease. Somehow, this RET R114H mutation proved to have a role in the etiology of both CIPO and HSCR and could contribute to a more diffuse imbalance of gut dysmotility. © 2016 Wiley Periodicals, Inc.

Front-line liquid biopsy for early molecular assessment and treatment of hospitalized lung cancer patients.

BACKGROUND: Molecular characterization is pivotal for managing non-small cell lung cancer (NSCLC), although this process is often time-consuming and patients' conditions might worsen while molecular analyses are processed. Our primary aim was to evaluate the performance of "up-front" next-generation sequencing (NGS) through liquid biopsy (LB) of hospitalized patients with newly detected lung neoplasm in parallel with conventional diagnosis. The secondary aim included longitudinal monitoring through LB of patients with oncogenic alterations at baseline. METHODS: We enrolled 47 consecutive patients immediately after hospitalization and radiological detection of symptomatic lung neoplasm. LB from peripheral blood was performed at baseline, in parallel with conventional biopsy (CB), when feasible. Additionally, LBs were repeated during treatment in patients with actionable gene alterations at baseline. Oncomine™ Lung cfTNA Research Assay panel was employed for processing plasma samples in NGS. RESULTS: 47 hospitalized patients were enrolled. LB identified 28 patients with gene alterations, including mutations of EGFR (n = 7), KRAS (n = 12), ERBB2 (n = 1), TP53 (n = 2), BRAF (n = 1), one ALK rearrangement, and 4 patients with combined mutations involving EGFR, KRAS and PIK3CA. LB and CB were consistent, except for two patients. Three patients with positive LB for oncogenic drivers did not undergo CB due to contraindications. Median time to molecular results after LB was significantly lower compared to time to molecular report after CB (11 versus 22 days, p < 0.001). CONCLUSIONS: Despite limited numbers, our study supports the role of front-line LB for improving management of symptomatic patients with lung cancer, potentially leading to early targeted therapy initiation.

Enterostomy-related complications in Hirschsprung's disease in a single cohort.

BACKGROUND: Hirschsprung's disease (HSCR) is a frequent cause of intestinal obstruction in children and may require an enterostomy. The study aimed to describe the most common enterostomy-related complications in a series of patients treated in a single center. METHODS: A series of consecutive HSCR patients treated or followed-up at our institution between January 1993 and December 2016 were included. Data about HSCR type, enterostomy site, duration and complications of the stoma were recorded. RESULTS: Three hundred one patients with HSCR were followed-up. Sixty-one had ultralong forms (TCSA/TIA), 21 had long forms (L-HSCR) and 219 had classic short forms (S-HSCR). One hundred thirty-seven patients required a stoma (100% of patients with TCSA/TIA, 66.7% with L-HSCR and 28.3% with S-HSCR). We observed 64 stoma-related complications: 36 major complications and 28 minor complications. Major complications occurred more often in long forms (P=0.037). The presence of an ileostomy was statistically associated with an increased rate of complications compared to colostomy. The longer the stoma was in site, the higher the complication rate was. CONCLUSIONS: Long and ultra-long forms are associated with a longer duration of the stoma and to a major risk of stoma-related complications.

Intrasphincteric Botox injections in Hirschsprung's disease: indications and outcome in 64 procedures over a ten-year period.

BACKGROUND: Intrasphincteric botulinum toxin (Botox) injection for symptomatic postoperative anal achalasia in Hirschsprung's disease (HSCR) has found wide application in the last twenty years. The aim of this study was to describe effectiveness and functional outcome of a series of patients treated over a 10-year period. METHODS: All consecutive HSCR patients who received intrasphincteric Botox injections between January 2007 and December 2016 were included. Demographic data and clinical features were collected. A detailed questionnaire focusing on outcome in the medium and long-term was administered to all families. RESULTS: In the study period 64 intrasphincteric Botox injections were performed in 31 patients. Completed questionnaires were returned by 27 out of 28 eligible patients (96%) reporting improvement or symptoms resolution in 16 (59%). The highest success rates were experienced by patients younger than 4, with long HSCR forms and with recurrent enterocolitis (75%, 100% and 100% of success rates, respectively). No major complications occurred. Minor complications were described by 7 patients (26%). CONCLUSIONS: Intrasphincteric Botox injection proved to be feasible, safe and reasonably effective in children with HSCR and postoperative anal achalasia. Infants and toddlers with long HSCR forms and recurrent bouts of enterocolitis are those who would benefit most from this treatment.

Interferon-γ-dependent inhibition of B cell activation by bone marrow-derived mesenchymal stem cells in a murine model of systemic lupus erythematosus.

OBJECTIVE: Bone marrow-derived mesenchymal stem cells (BM-MSCs) are multipotent cells characterized by immunomodulatory properties and are therefore considered a promising tool for the treatment of immune-mediated diseases. This study was undertaken to assess the influence of murine BM-MSCs on the activation of B cells in (NZB × NZW)F(1) mice as an animal model of systemic lupus erythematosus (SLE). METHODS: We evaluated the in vitro effects of BM-MSCs on the proliferation and differentiation to plasma cells of splenic mature B cell subsets, namely follicular and marginal zone B cells isolated from (NZB × NZW)F(1) mice. Lupus mice were also treated with BM-MSCs, and serum autoantibodies, proteinuria, histologic changes in the kidney, and survival rates were monitored. RESULTS: BM-MSCs inhibited antigen-dependent proliferation and differentiation to plasma cells of follicular and marginal zone B cells in vitro. This inhibitory effect was dependent on interferon-γ (IFNγ) and was mediated by cell-to-cell contact, involving the programmed death 1 (PD-1)/PD ligand pathway. In vivo treatment with BM-MSCs did not affect the levels of anti-double-stranded DNA antibodies or proteinuria. However, a reduction in glomerular immune complex deposition, lymphocytic infiltration, and glomerular proliferation was observed. CONCLUSION: Our findings indicate that BM-MSCs affect B cell receptor-dependent activation of both follicular and marginal zone B cells from lupus mice. This inhibitory effect is IFNγ-dependent and cell contact-dependent. MSCs in vivo do not affect the production of autoantibodies, the level of proteinuria, or the mortality rates. Nonetheless, the significant improvement in histologic findings in the kidney supports the potential role of MSCs in the prevention of glomerular damage.

Hirschsprung disease and Down syndrome: From the reappraisal of risk factors to the impact of surgery.

INTRODUCTION: The association of Hirschsprung disease (HSCR) and Down Syndrome (DS) is not uncommon (HSCR+DS). This paper aims at reporting the results of a 24-year series focusing on surgical approach, complications and long term outcome. MATERIALS AND METHODS: The notes of all patients admitted with a diagnosis of HSCR+DS have been retrospectively reviewed. Surgical details, intraoperative complications, long term issues and functional outcome have been recorded. The results have been compared to those of patients without DS and were assessed based on surgical approach. RESULTS: A total of 23 HSCR+DS out of a series of 385 HSCR (6%) have been included. Preoperative enterocolitis (HAEC) was reported by 32%. Associated anomalies were detected in more than half of the patients. In particular, Congenital Heart Defects (CHDs) were reported by 57%. Postoperative complications (mostly symptomatic anal sphincter achalasia) were experienced by 55%. Constipation was experienced by 30%; severe continence issues, by 53%. One patient suffering from severe CHDs died. With regard to complications, only symptomatic anal achalasia requiring intrasphincteric BoTox injection was significantly more frequent in HSCR+DS (30% vs 10%, p = 0.0071). Similarly, continence proved to be significantly worse in HSCR+DS. DISCUSSION: With the exception of symptomatic anal achalasia, HSCR+DS patients proved not to have a higher likelihood of complications compared to HSCR alone. On the other hand, functional results in the long term are worse. As a consequence, long term follow up and personalized rehabilitation programs are warranted for this delicate subset of HSCR patients. LEVEL OF EVIDENCE: Level III.

Copy number variations in candidate genomic regions confirm genetic heterogeneity and parental bias in Hirschsprung disease.

BACKGROUND: Hirschsprung Disease (HSCR) is a congenital defect of the intestinal innervations characterized by complex inheritance. Many susceptibility genes including RET, the major HSCR gene, and several linked regions and associated loci have been shown to contribute to disease pathogenesis. Nonetheless, a proportion of patients still remains unexplained. Copy Number Variations (CNVs) have already been involved in HSCR, and for this reason we performed Comparative Genomic Hybridization (CGH), using a custom array with high density probes. RESULTS: A total of 20 HSCR candidate regions/genes was tested in 55 sporadic patients and four patients with already known chromosomal aberrations. Among 83 calls, 12 variants were experimentally validated, three of which involving the HSCR crucial genes SEMA3A/3D, NRG1, and PHOX2B. Conversely RET involvement in HSCR does not seem to rely on the presence of CNVs while, interestingly, several gains and losses did co-occur with another RET defect, thus confirming that more than one predisposing event is necessary for HSCR to develop. New loci were also shown to be involved, such as ALDH1A2, already found to play a major role in the enteric nervous system. Finally, all the inherited CNVs were of maternal origin. CONCLUSIONS: Our results confirm a wide genetic heterogeneity in HSCR occurrence and support a role of candidate genes in expression regulation and cell signaling, thus contributing to depict further the molecular complexity of the genomic regions involved in the Enteric Nervous System development. The observed maternal transmission bias for HSCR associated CNVs supports the hypothesis that in females these variants might be more tolerated, requiring additional alterations to develop HSCR disease.

A Metagenomics Study on Hirschsprung's Disease Associated Enterocolitis: Biodiversity and Gut Microbial Homeostasis Depend on Resection Length and Patient's Clinical History.

Objectives: Since 2010, several researches demonstrated that microbiota dynamics correlate and can even predispose to Hirschsprung (HSCR) associated enterocolitis (HAEC). This study aims at assessing the structure of the microbiota of HSCR patients in relation to extent of aganglionosis and HAEC status. Methods: All consecutive HSCR patients admitted to Gaslini Institute (Genova, Italy) between May 2012 and November 2014 were enrolled. Institutional review board (IRB) approval was obtained. Stools were sampled and 16S rDNA V3-V4 regions were sequenced using the Illumina-MiSeq. Taxonomy assignments were performed using QIIME RDP. Alpha diversity indexes were analyzed by Shannon and Simpson Indexes, and Phylogenetic Diversity. Results: We enrolled 20 patients. Male to female ratio was 4:1. Six patients suffered from Total Colonic Aganglionosis (TCSA). Considering sample site (i.e., extent of aganglionosis), we confirmed the known relationship between sample site and both biodiversity and composition of intestinal microbiota. Patients with TCSA showed lower biodiversity and increased Proteobacteria/Bacteroidetes relative abundance ratio. When addressing biodiversity, composition and dynamics of TCSA patients we could not find any significant relationship with regard to HAEC occurrences. Conclusions: The composition of HAEC predisposing microbiota is specific to each patient. We could confirm that total colon resections can change the composition of intestinal microbiota and to dramatically reduce microbial diversity. The subsequent reduction of system robustness could expose TCSA patients to environmental microbes that might not be part of the normal microbiota. Future long-term studies should investigate both patients and their family environment, as well as their disease history.

Variants of the ACTG2 gene correlate with degree of severity and presence of megacystis in chronic intestinal pseudo-obstruction.

Chronic intestinal pseudo-obstruction (CIPO) syndromes are heterogeneous gastrointestinal disorders, caused by either neuropathy or myopathy, resulting in compromised peristalsis and intestinal obstruction. CIPO can have a profound impact on quality of life, leading the most severely affected individuals to life-long parenteral nutrition and urinary catheterization. To search for disease causing gene(s), we performed the whole exome sequencing (WES) in both eight sporadic and two familial cases, followed by targeted sequencing in additional CIPO patients. After identifying a heterozygous missense variant in the ACTG2 gene in one of 10 patients undergone WES, targeted Sanger sequencing of this gene allowed to detect heterozygous missense variants in 9 of 23 further patients with either megacystis-microcolon-intestinal hypoperistalsis syndrome or intestinal pseudo-obstruction. Variants thus identified, one of which still unreported, affect highly conserved regions of the ACTG2 gene that encodes a protein crucial for correct enteric muscle contraction. These findings provided evidence for a correlation between the clinical phenotype and genotype at the ACTG2 locus, a first step to improve the diagnosis and prognosis of these severe conditions.

Hirschsprung's Disease and Associated Congenital Heart Defects: A Prospective Observational Study from a Single Institution.

OBJECTIVE: To define the prevalence and characteristics of associated congenital heart diseases (CHDs) in patients with Hirschsprung's disease (HSCR). METHOD: All patients with a histological diagnosis of HSCR admitted to our hospital between January 2010 and December 2013 were included in this prospective observational study and underwent cardiovascular screening. Cardiac anatomy was assessed by a segmental echocardiographic approach. Measurements of aortic root and left ventricular dimensions, wall thickness, and function were obtained. CHDs requiring a percutaneous or surgical intervention were described as major heart diseases. RESULTS: One hundred thirty-three consecutive patients were enrolled at median age of 2.3 years. Eleven patients (8.3%) presented an associated heart disease. Moreover, five patients had mild dilatation of aortic root. Six out of 11 (4.5%) patients had a major CHDs requiring surgical repair. CONCLUSION: Prevalence of associated CHDs was slightly higher than in previous papers, and mostly represented by septal defects. Four out of six patients with major heart disease had also a chromosomal anomaly. If we do not consider the subpopulation of patients with a chromosomal anomaly, cardiac defects were present in 3.8% of the patients. Based on these results, we suggest to perform routine echocardiogram in all Hirschsprung patients, with or without associated chromosomal syndromes.

A prospective observational study of associated anomalies in Hirschsprung's disease.

BACKGROUND: Associated anomalies have been reported in around 20% of Hirschsprung patients but many Authors suggested a measure of underestimation. We therefore implemented a prospective observational study on 106 consecutive HSCR patients aimed at defining the percentage of associated anomalies and implementing a personalized and up-to-date diagnostic algorithm. METHODS: After Institutional Ethical Committee approval, 106 consecutive Hirschsprung patients admitted to our Institution between January 2010 and December 2012 were included. All families were asked to sign a specific Informed Consent form and in case of acceptance each patient underwent an advanced diagnostic algorithm, including renal ultrasound scan (US), cardiologic assessment with cardiac US, cerebral US, audiometry, ENT and ophthalmologic assessments plus further specialist evaluations based on specific clinical features. RESULTS: Male to female ratio of our series of patients was 3,4:1. Aganglionosis was confined to the rectosigmoid colon (classic forms) in 74,5% of cases. We detected 112 associated anomalies in 61 (57,5%) patients. The percentage did not significantly differ according to gender or length of aganglionosis. Overall, 43,4% of patients complained ophthalmologic issues (mostly refraction anomalies), 9,4% visual impairment, 20,7% congenital anomalies of the kidney and urinary tract, 4,7% congenital heart disease, 4,7% hearing impairment or deafness, 2,3% central nervous system anomalies, 8,5% chromosomal abnormalities or syndromes and 12,3% other associated anomalies. CONCLUSIONS: Our study confirmed the underestimation of certain associated anomalies in Hirschsprung patients, such as hearing impairment and congenital anomalies of the kidney and urinary tract. Subsequently, based on our results we strongly suggest performing renal US and audiometry in all patients. Conversely, ophthalmologic assessment and cerebral and heart US can be performed according to guidelines applied to the general population or in case of patients with suspected clinical features or chromosomal abnormalities. This updated diagnostic algorithm aims at improving overall outcome thanks to better prognostic expectations, prevention strategies and early rehabilitation modalities. The investigation of genetic background of patients with associated anomalies might be the next step to explore this intriguing multifactorial congenital disease.

Oct-4+/Tenascin C+ neuroblastoma cells serve as progenitors of tumor-derived endothelial cells.

Neuroblastoma (NB)-associated endothelial microvessels (EMs) may be lined by tumor-derived endothelial cells (TECs), that are genetically unstable and chemoresistant. Here we have addressed the identification of TEC progenitors in NB by focusing on Octamer-binding transcription factor 4 (Oct-4) as a putative marker. Oct-4(+) cells were detected in primary NB samples (n = 23), metastatic bone marrow aspirates (n = 10), NB cell lines (n = 4), and orthotopic tumors (n = 10) formed by the HTLA-230 NB cell line in immunodeficient mice. Most Oct-4(+) cells showed a perivascular distribution, with 5% of them homing in perinecrotic areas. All Oct-4(+) cells were tumor-derived since they shared amplification of MYCN oncogene with malignant cells. Perivascular Oct-4(+) cells expressed stem cell-related, neural progenitor-related and NB-related markers, including surface Tenascin C (TNC), that was absent from perinecrotic Oct-4(+) cells and bulk tumor cells. TNC(+) but not TNC(-) HTLA-230 cells differentiated in vitro into endothelial-like cells expressing vascular-endothelial-cadherin, prostate-specific membrane antigen and CD31 upon culture in medium containing vascular endothelial growth factor (VEGF). TNC(+) but not TNC(-) HTLA-230 cells formed neurospheres when cultured in serum-free medium. Both cell fractions were tumorigenic, but only tumors formed by TNC(+) cells contained EMs lined by TECs. In conclusion, we have identified in NB tumors two putative niches containing Oct-4(+) tumor cells. Oct-4(+)/TNC(+) perivascular NB cells displayed a high degree of plasticity and served as progenitors of TECs. Therapeutic targeting of Oct4(+)/TNC(+) progenitors may counteract the contribution of NB-derived ECs to tumor relapse and chemoresistance.