Th17 Cell-Derived Amphiregulin Promotes Colitis-Associated Intestinal Fibrosis Through Activation of mTOR and MEK in Intestinal Myofibroblasts.

BACKGROUND & AIMS: Intestinal fibrosis is a significant complication of Crohn's disease (CD). Gut microbiota reactive Th17 cells are crucial in the pathogenesis of CD; however, how Th17 cells induce intestinal fibrosis is still not completely understood. METHODS: In this study, T-cell transfer model with wild-type (WT) and Areg-/- Th17 cells and dextran sulfate sodium (DSS)-induced chronic colitis model in WT and Areg-/- mice were used. CD4+ T-cell expression of AREG was determined by quantitative reverse-transcriptase polymerase chain reaction and enzyme-linked immunosorbent assay. The effect of AREG on proliferation/migration/collagen expression in human intestinal myofibroblasts was determined. AREG expression was assessed in healthy controls and patients with CD with or without intestinal fibrosis. RESULTS: Although Th1 and Th17 cells induced intestinal inflammation at similar levels when transferred into Tcrßxδ-/- mice, Th17 cells induced more severe intestinal fibrosis. Th17 cells expressed higher levels of AREG than Th1 cells. Areg-/- mice developed less severe intestinal fibrosis compared with WT mice on DSS insults. Transfer of Areg-/- Th17 cells induced less severe fibrosis in Tcrßxδ-/- mice compared with WT Th17 cells. Interleukin (IL)6 and IL21 promoted AREG expression in Th17 cells by activating Stat3. Stat3 inhibitor suppressed Th17-induced intestinal fibrosis. AREG promoted human intestinal myofibroblast proliferation, motility, and collagen I expression, which was mediated by activating mammalian target of rapamycin and MEK. AREG expression was increased in intestinal CD4+ T cells in fibrotic sites compared with nonfibrotic sites from patients with CD. CONCLUSIONS: These findings reveal that Th17-derived AREG promotes intestinal fibrotic responses in experimental colitis and human patients with CD. Thereby, AREG might serve as a potential therapeutic target for fibrosis in CD.

Creating a Surgical Biobank: The Hershey Medical Center Experience.

BACKGROUND: Tissue harvesting at the time of surgery offers surgeons and scientists a unique opportunity to discover and better understand disease pathophysiology. Tissue biobanking presents challenges in patient consents, specimen collection, preparation, and storage, but the potential for scientific discovery justifies the effort. Although the number of tissue biobanks is increasing worldwide, information regarding necessary infrastructure, process flow, and management of expected obstacles is lacking. OBJECTIVE: To provide a framework and motivation for clinician scientists intending to start an intestinal tissue biobank under their direction. DATA SOURCES: The Carlino Family Inflammatory Bowel and Colorectal Diseases Biobank is housed at the Milton S. Hershey Medical Center. STUDY SELECTION: Review. INTERVENTION: Implementation of a surgical tissue biobank at a large tertiary care institution. MAIN OUTCOME MEASURES: Assess critical challenges and obstacles over the years as well as keys to the success of the program. RESULTS: Over 2 decades, the institutional biobank grew from an IBD biobank to one which now incorporates thousands of surgical specimens representing numerous colorectal diseases. This was done through a process of refinement focusing on patient recruitment and an efficient consenting and specimen management process. The biobank's success is further insured by institutional, external, and philanthropic support; scientific collaborations; and sharing of biological specimens with other groups of dedicated researchers. LIMITATIONS: This is a single-center experience in collecting surgically resected colorectal specimens. CONCLUSIONS: Surgical specimen biobanks are essential in studying disease cause using genomics, transcriptomics, and proteomic technologies. Therefore, surgeons, clinicians, and scientists should build biobanks at their institutions to promote further scientific discovery and improve specimen diversity.

Characteristics and Outcomes of Right- Versus Left-Sided Early-Onset Colorectal Cancer.

BACKGROUND: Early-onset colorectal cancers are increasing in incidence. Studies reported more left-sided cancers in patients aged <50 years. Some advocate for screening via flexible sigmoidoscopy at age 40 years. OBJECTIVE: The purpose of this study was to investigate characteristics and outcomes in sporadic right- and left-sided early-onset colorectal cancers. DESIGN: This was a retrospective cohort study. SETTINGS: This study was conducted at a single, tertiary care institution. PATIENTS: This study included patients aged <50 years diagnosed with colorectal cancer between 2000 and 2018. MAIN OUTCOME MEASURES: We analyzed patient demographics, tumor characteristics, and survival. RESULTS: A total of 489 patients aged 20 to 49 years were identified from 2000 to 2018. The majority of patients were white (90%) and male (57%). The median age at diagnosis was 44 years, and 75% were diagnosed at age 40-49 years. There was a predominance of left-sided tumors (80%). The majority of patients presented with stage 3 (35%) and stage 4 (35%) disease. Right-sided tumors were more likely to have mucinous (24% vs 7.4%; p < 0.001) and signet-ring cell (4.4% vs 1.7%; p < 0.001) histology. There was no difference in age, sex, race, ethnicity, and stage at presentation. Right-sided tumors were associated with lower 5-year overall survival (44% vs 61%; p < 0.005) with the decrease in survival most prominent in right-sided stage 3 tumors (41% vs 72%; p < 0.0001) and in ages 40 to 49 years (43% vs 61%; p = 0.03). Sex, tumor location, increasing stage, and signet-ring cell histology were independent prognostic factors of overall survival. There was no difference in disease-free survival. LIMITATIONS: This study was a retrospective review at a single institution. CONCLUSIONS: The majority of early-onset colorectal cancers arise from age 40 to 49 years with a left-sided predominance but higher mortality in right-sided tumors. These findings provide further evidence in favor of recommending earlier initial screening colonoscopy for colorectal cancer. See Video Abstract at http://links.lww.com/DCR/B892 . CARACTERSTICAS Y RESULTADOS DEL CNCER COLORRECTAL DE INICIO TEMPRANO DEL LADO DERECHO FRENTE AL IZQUIERDO: ANTECEDENTES:Los cánceres colorrectales de aparición temprana están aumentando en incidencia. Los estudios han informado una preponderancia de cánceres en el lado izquierdo en pacientes <50 años, lo que ha llevado a algunos a abogar por la detección con sigmoidoscopia flexible a los 40 años.OBJETIVO:El propósito de nuestro estudio fue investigar las características del tumor y los resultados de los pacientes en cánceres colorrectales esporádicos del lado derecho e izquierdo de aparición temprana.DISEÑO:Este fue un estudio de cohorte retrospectivo.ENTORNO CLÍNICO:Este estudio se realizó en una única institución de atención terciaria.PACIENTES:Pacientes <50 años diagnosticados de cáncer colorrectal entre 2000 y 2018.RESULTADO PRINCIPAL:Analizamos los datos demográficos de los pacientes, las características del tumor, la supervivencia general y la supervivencia libre de enfermedad.RESULTADOS:Se identificaron un total de 489 pacientes de entre 20 y 49 años entre 2000 y 2018. La mayoría de los pacientes eran blancos (90%) y varones (57%). La mediana de edad en el momento del diagnóstico fue de 44 años y el 75% se diagnosticó entre los 40 y los 49 años. Predominó los tumores del lado izquierdo (80%). La mayoría de los pacientes presentaban enfermedad en estadio 3 (35%) y estadio 4 (35%). Los tumores del lado derecho tenían más probabilidades de tener histología mucinosa (24% frente a 7,4%, p < 0,001) y de células en anillo de sello (4,4% frente a 1,7%, p < 0,001). No hubo diferencia en edad, sexo, raza, etnia, estadio AJCC en la presentación. Los tumores del lado derecho se asociaron con una menor supervivencia general a 5 años (44% frente al 61%, p < 0,005) con la disminución de la supervivencia más prominente en los tumores del lado derecho en estadio 3 (41% frente al 72%, p < 0,0001) y en edades 40-49 (43% vs 61%, p = 0.03). El sexo, la ubicación del tumor, el estadio AJCC en aumento y la histología de las células en anillo de sello fueron factores pronósticos independientes de la supervivencia general. No hubo diferencias significativas en la supervivencia libre de enfermedad.LIMITACIONES:Este estudio fue una revisión retrospectiva en una sola institución.CONCLUSIONES:La mayoría de los cánceres colorrectales de aparición temprana surgen entre los 40 y los 49 años con un predominio en el lado izquierdo pero una mayor mortalidad en los tumores del lado derecho. Estos hallazgos proporcionan evidencia adicional a favor de recomendar una colonoscopia de detección inicial más temprana para el cáncer colorrectal. Consulte Video Resumen en http://links.lww.com/DCR/B892 . (Traducción-Dr. Ingrid Melo ).

The Microbiome of Complicated Diverticulitis: An Imbalance of Sulfur-Metabolizing Bacteria.

BACKGROUND: The progression to acute diverticulitis from the relatively benign condition of colonic diverticulosis is not well characterized. A smaller subset may even develop complicated (perforated) diverticulitis resulting in sepsis and/or death. Characterizing the differences between recurrent, uncomplicated diverticulitis, and the more virulent, complicated diverticulitis is necessary to guide clinical decision-making. Alterations to the microbiome offer a possible explanation for local inflammation and the pathophysiology of diverticular disease. OBJECTIVE: This study aimed to characterize the mucosal-associated microbiome in patients with recurrent uncomplicated diverticulitis and complicated (perforated) diverticulitis. DESIGN: Microbial DNA was extracted from full-thickness surgical specimens for 16S rRNA gene sequencing, targeting the V4 hypervariable region. Sequences were analyzed and a quantitative characterization based on taxonomic classification was performed. SETTING: A tertiary care academic medical center. PATIENTS: This study compared 48 patients with recurrent, uncomplicated diverticulitis and 35 patients with radiographically confirmed perforated (complicated) diverticulitis. Tissues were harvested from surgical resection specimens to include both diseased regions and nondiseased (adjacent normal) regions. MAIN OUTCOME MEASURES: We assessed differences in relative abundance and taxonomic classification of mucosal-associated microbes in surgical resection specimens from diverticular disease. RESULTS: When analyzing the tissue of diverticular resection specimens, the complicated diseased segments demonstrated an increased abundance of sulfur-reducing and sulfur-oxidizing bacteria compared to nondiseased, adjacent normal regions. When comparing diseased segments, tissues of patients with complicated diverticulitis had a marked increase in sulfur-reducing microbes. LIMITATIONS: We characterized the mucosal-associated microbiome present at the time of surgical resection, limiting conclusions on its role in pathophysiology. Furthermore, antibiotic usage and bowel preparation before surgery may result in perturbations to microbial flora. CONCLUSIONS: The microbiome of complicated diverticulitis is marked by a localized imbalance of sulfur-metabolizing microbes. The abundance of sulfur-reducing microbes may lead to an excess of hydrogen sulfide and subsequent inflammation. See Video Abstract at http://links.lww.com/DCR/C175 . LA MICROBIOMA DE LA DIVERTICULITIS COMPLICADA UN DESEQUILIBRIO DE LAS BACTERIAS METABOLIZADORAS DE AZUFRE: ANTECEDENTES: La progresión a diverticulitis aguda de la condición relativamente benigna de diverticulosis colónica no está bien caracterizada. Un subgrupo más pequeño puede incluso desarrollar diverticulitis complicada (perforada) que resulta en sepsis y/o muerte. Es necesario caracterizar las diferencias entre la diverticulitis recurrente no complicada y la diverticulitis complicada más virulenta para guiar la toma de decisiones clínicas. Las alteraciones del microbioma ofrecen una posible explicación de la inflamación local y la fisiopatología de la enfermedad diverticular.OBJETIVO: Caracterizar el microbioma asociado a la mucosa en pacientes con diverticulitis no complicada recurrente y diverticulitis complicada (perforada).DISEÑO: El ADN microbiano se extrajo de especímenes quirúrgicos de espesor completo para la secuenciación del gen 16S rRNA, dirigido a la región hipervariable V4. Se analizaron las secuencias y se realizó una caracterización cuantitativa basada en la clasificación taxonómica.AJUSTE: Un centro médico académico de atención terciaria.PACIENTES: Este estudio comparó 48 pacientes con diverticulitis recurrente no complicada y 35 pacientes con diverticulitis perforada (complicada) confirmada radiográficamente. Se recogieron tejidos de especímenes de resección quirúrgica para incluir tanto regiones enfermas como regiones no enfermas (normales adyacentes).PRINCIPALES MEDIDAS DE RESULTADO: Evaluamos las diferencias en la abundancia relativa y la clasificación taxonómica de los microbios asociados a la mucosa en muestras de resección quirúrgica de enfermedad diverticular.RESULTADOS: Al analizar el tejido de las muestras de resección diverticular, los segmentos enfermos complicados demostraron una mayor abundancia de bacterias reductoras de azufre y oxidantes de azufre en comparación con las regiones normales adyacentes no enfermas. Al comparar segmentos enfermos, los tejidos de pacientes complicados tenían un marcado aumento de microbios reductores de azufre.LIMITACIONES: Caracterizamos el microbioma asociado a la mucosa presente en el momento de la resección quirúrgica, lo que limita las conclusiones sobre su papel en la fisiopatología. Además, el uso de antibióticos y la preparación intestinal antes de la cirugía pueden provocar alteraciones en la flora microbiana.CONCLUSIONES: El microbioma de la diverticulitis complicada está marcado por un desequilibrio localizado de microbios metabolizadores de azufre. La abundancia de microbios reductores de azufre puede provocar un exceso de sulfuro de hidrógeno y la consiguiente inflamación. Consulte Video Resumen en http://links.lww.com/DCR/C175 . (Traducción-Dr. Ingrid Melo ).

Stoma-less IPAA Is Not Associated With Increased Anastomotic Leak Rate or Long-term Pouch Failure in Patients With Ulcerative Colitis.

BACKGROUND: There is debate regarding the utility of diverting loop ileostomy with IPAA construction in patients requiring colectomy for ulcerative colitis. OBJECTIVE: This study aimed to determine whether the omission of diverting loop ileostomy at the time of IPAA construction increases the risk of complications. DESIGN: This was a retrospective study. SETTINGS: The study was conducted in a high-volume, quaternary referral center with an IBD program. PATIENTS: The patients, who underwent IPAA with or without ileostomy, were diagnosed for ulcerative colitis. MAIN OUTCOME MEASURES: Anastomotic leak rate and pouch failure rates were determined between patients who either had a diverting ileostomy at the time of IPAA creation or had stoma-less IPAA. RESULTS: Of the 414 patients included in this study, 91 had stoma-less IPAA. When compared to IPAA with diverting loop ileostomy, patients with stoma-less IPAA were less likely to be taking prednisone and had decreased blood loss. Short- and long-term outcomes were similar when comparing stoma-less IPAA and IPAA with diverting loop ileostomy, with no significant difference in anastomotic leak rate and long-term pouch failure rates. Diverting loop ileostomy was associated with a 14.6% risk of complication at the time of stoma reversal. LIMITATIONS: The study is limited by its retrospective nature. CONCLUSIONS: The results of this study suggest that the omission of a diverting ileostomy is feasible in select patients undergoing IPAA. Stoma-less IPAA does not have a statistically significant higher risk of anastomotic leak or pouch failure when compared to IPAA with diverting loop ileostomy in properly selected patients. Diverting loop ileostomies have their own risks, which partially offset their perceived safety. See Video Abstract at http://links.lww.com/DCR/B891 .LA ANASTOMÓSIS DE RESERVORIO ILEAL AL ANO SIN ESTOMA NO ESTÁ ASOCIADO CON UN AUMENTO EN LA TASA DE FUGA ANASTOMÓTICA O DISFUNCIÓN DE LA BOLSA A LARGO PLAZO EN PACIENTES CON COLITIS ULCERATIVA. ANTECEDENTES: Existe debate en lo que respecta a la utilidad de efectuar una ileostomía en asa en la construcción de una anastomosis de reservorio ileal al ano en pacientes que requieren colectomía para colitis ulcerativa. OBJETIVO: Determinar si el evitar una ileostomía de derivación en el momento de efectuar una anstomósis de reservorio ileal al ano aumenta el riesgo de complicaciones. DISEO: Estudio retrospectivo. REFERENCIA: Centro de referencia de cuarto nivel de grandes volúmenes con programa de enfermedad inflamatoria intestinal. PACIENTES: Con diagnóstico de colitis ulcerativa sometidos a anastomosis de reservorio ileal al ano con o sin ileostomía derivative. PRINCIPALES MEDIDAS DE RESULTADOS: Tasa de fuga anastomótica y disfunción del reservorio en pacientes sometidos a anastomosis de reservorio ileal al ano con ileostomía derivativa en el mismo evento y aquellos sin derivación de protección. RESULTADOS: De los 414 pacientes incluídos en el estudio, 91 no contaban con ileostomía de protección de la anastomosis del reservorio ileal al ano. Al comprarse con aquellos con ileostomía derivativa, aquellos sin estoma requirieron menor dosis de prednisona y presentaron menor pérdida sanguínea. Los resultados a corto y largo plazo fueron similares al comprar ambos grupos sin haber evidencia significativa de fuga anastomótica o falla del reservorio a largo plazo. La derivación con ileostomía en asa se asoció en un 14.6% de riesgo de complicaciones al efectuar el cierre de la misma. LIMITACIONES: Es una revision retrospectiva. CONCLUSIONES: : Los resultados de este estudio sugieren que la omisión de una ileostomía de protección es posible en pacientes seleccionados sometidos a una anastomosis de reservorio ileoanal. La anastomosis sin derivación de protección no confiere un riesgo estadísticamente significativo de fuga anastomótica o disfunción de la misma al compararse con el procedimiento con estoma derivativo en pacientes seleccionados. Las ileostomías de derivación en asa tienen su propia morbilidad que cuestiona la perfección de su seguridad. Consulte Video Resumen at http://links.lww.com/DCR/B891 . (Traducción- Dr. Miguel Esquivel-Herrera ).

Clinical and Genetic Factors Impact Time to Surgical Recurrence After Ileocolectomy for Crohn's Disease.

OBJECTIVE: The aim of this study was to evaluate factors associated with time to surgical recurrence after Crohn's ileocolectomy. SUMMARY BACKGROUND DATA: The most common surgery performed for Crohn's disease is ileocolectomy. Identifying patients at high risk for surgical recurrence may assist with medical and surgical decision-making. METHODS: Data were obtained from 409 patients with Crohn's disease (CD) who had undergone ≥1 ileocolectomies at Penn State Hershey Medical Center. Six single-nucleotide polymorphisms (SNPs) associated with CD were evaluated in these patients: rs2076756, rs2066844, and rs2066845 in NOD2, rs4958847 and rs13361189 in IRGM, and rs2241880 in ATG16L1. Genotype and clinical factors were analyzed to determine associations with time to recurrent ileocolectomy. A subgroup analysis was performed on 241 patients naïve to biologics before initial ileocolectomy to assess the effect of biologic therapy on time to recurrent surgery. RESULTS: There were 286 patients who underwent a single ileocolectomy, whereas 123 required multiple ileocolectomies. Ileocolonic involvement [hazard ratio (HR) 1.90, 95% confidence interval (CI) 1.21-3.00, P = 0.006] and rs2066844 in NOD2 (HR 1.8, 95% CI 1.17-2.77, P = 0.007) were associated with decreased time to surgical recurrence by multivariate analysis. In patients naïve to preoperative biologics, the initiation of postoperative biologics was associated with a 40% decreased incidence of surgical recurrence (HR 0.60, CI 0.39-0.93, P = 0.02) over time. CONCLUSIONS: Ileocolonic distribution of disease and the rs2066844 SNP in NOD2 are associated with shorter time to recurrent ileocolectomy. The initiation of postoperative biologics in naïve patients was associated with a reduced incidence of recurrence over time.

CD163L1+CXCL10+ Macrophages are Enriched Within Colonic Lamina Propria of Diverticulitis Patients.

BACKGROUND: Inflammation of diverticula, which are outpouchings of the colonic bowl wall, causes diverticulitis. Severe cases of diverticulitis require surgical intervention. Through RNA-seq analysis of intestinal tissues, we previously found that the innate immune response was deregulated in surgical diverticulitis patients. In that study, pro-inflammatory and macrophage markers were differentially expressed in the colons of diverticulitis versus control patients. Here we investigate CD163L1+ macrophages and the pro-inflammatory chemokine, CXCL10, in diverticulitis. MATERIALS AND METHODS: We assessed tissue from an uninvolved area adjacent to a region of the sigmoid colon chronically affected by diverticulitis and performed Spearman's correlation on transcripts associated with macrophage signaling. We identified altered CD163L1 and CXCL10 gene expression levels that we confirmed by RT-qPCR analysis on an independent cohort of diverticulitis patients and controls. We used immunofluorescence microscopy to localize CD163L1+ macrophages and CXCL10 levels in intestinal tissue and ELISA to measure CXCL10 levels in patient serum. RESULTS: We found a positive correlation between intestinal CD163L1 and CXCL10 gene expression and an increased number of CD163L1+ macrophages in the sigmoid colons of diverticulitis patients relative to controls (P = 0.036). Macrophages at the apices of colonic crypts expressed the chemokine CXCL10. Correspondingly, these diverticulitis patients also displayed heightened CXCL10 levels in their serum (P = 0.007). CONCLUSIONS: We identified a novel population of CD163L1+CXCL10+ macrophages in the colonic crypts of diverticulitis patients and demonstrated increased expression of serum CXCL10 in these patients. CXCL10 may serve as a prognostic biomarker to aid in clinical decision making for diverticulitis patients.

COLQ and ARHGAP15 are Associated with Diverticular Disease and are Expressed in the Colon.

BACKGROUND: Diverticular disease is a common but poorly understood disease of the gastrointestinal tract. Recent studies have identified several single nucleotide polymorphisms (SNPs) that are associated with diverticular disease. MATERIALS AND METHODS: The genotypes of three SNPs (rs4662344 in ARHGAP15, rs7609897 in COLQ, and rs67153654 in FAM155A) were identified by Taqman assay in 204 patients with diverticular disease. Clinical characteristics were obtained from the medical record to study association with genotype. To evaluate gene expression in colon tissue, qPCR was performed on 24 patients with diverticulitis, and COLQ was localized using immunohistochemistry. RESULTS: The ARHGAP15 and COLQ SNPs were significantly associated with both diverticular disease and specifically diverticulitis, while the FAM155A was not associated with either. No association was found with clinical disease characteristics. Heterozygous genotypes at the ARHGAP15 SNP was associated with lower ARHGAP15 expression in colon tissues. COLQ protein localized to the myenteric plexus in the colon. CONCLUSIONS: This study confirmed association of the ARHGAP15 and COLQ SNPs with diverticular disease in our patients but could not confirm FAM155A SNP association. Neither of these SNPs appeared to associate with more severe disease, but genotype at the ARHGAP15 SNP did impact expression of ARHGAP15 in the colon. Additionally, this study is the first to localize COLQ in the colon. Its presence in the myenteric nervous system suggests COLQ SNP variants may contribute to diverticular disease by altering motility.

Special Considerations of Anastomotic Leaks in Crohn's Disease.

Rates of anastomotic leak following intestinal resections in the setting of inflammatory bowel disease are significantly influenced by clinical characteristics. While the literature can be contradictory due to significant heterogeneity in the published data, several common themes appear to consistently arise. With respect to Crohn's disease, low serum albumin, preoperative abscess, reoperative abdominal surgery, and steroid use are associated with an increased risk of postoperative intra-abdominal septic complications. On the contrary, biologic therapy, immunomodulator use, and method of anastomosis appear not to confer increased anastomotic-related complications. Undoubtedly, a low rate of anastomotic leakage is inherent to procedures within colorectal surgery but diligent attention must be paid to identify, optimize, and, therefore, reduce known risks.

Transcriptomic analysis of ileal tissue from Crohn's disease patients identifies extracellular matrix genes that distinguish individuals by age at diagnosis.

Crohn's disease (CD) is a debilitating gastrointestinal (GI) disorder that can impact the entirety of the GI tract. While substantial progress has been made in the medical management of CD, it remains incurable, frequently relapses, and is a significant financial and medical burden. The pathophysiology of CD is not well understood, but it is thought to arise in genetically susceptible individuals upon an environmental insult. Further elucidation of the disease etiology promises to expose additional therapeutic avenues, with the hope of reducing the burden of CD. One approach to understanding disease pathophysiology is to identify clinically relevant molecular disease subsets by using transcriptomics. In this report, we use hierarchical clustering of the ileal transcriptomes of 34 patients and identify two CD subsets. Clinically, these clusters differed in the age of the patients at CD diagnosis, suggesting that age of onset affects disease pathophysiology. The clusters were segregated by three major gene ontology categories: developmental processes, ion homeostasis, and the immune response. Of the genes constituting the immune system category, expression of extracellular matrix-associated genes, COL4A1, S100A9, ADAMTS2, SERPINE1, and FCN1, exhibits the strongest correlation with an individual's age at CD diagnosis. Together these findings demonstrate that transcriptional profiling is a powerful approach to subclassify CD patients.

Clinical and Genetic Factors Associated With Complications After Crohn's Ileocolectomy.

BACKGROUND: Ileocolectomy is the most common surgery performed for Crohn's disease, and postoperative complications occur frequently. There has been minimal evaluation of complications after ileocolectomy as a function of both clinical and genetic factors. OBJECTIVE: The purpose of this study was to evaluate both genetic and clinical factors associated with complications after Crohn's ileocolectomy. DESIGN: This was a retrospective clinical and genetic cohort study. SETTINGS: This study was conducted at a high-volume tertiary care center. PATIENTS: We identified 269 patients with Crohn's disease who had undergone 287 ileocolectomies at our institution between July 2008 and October 2018. MAIN OUTCOME MEASURES: We measured the association of complications with a combination of clinical factors and 6 Crohn's-associated single nucleotide polymorphisms in NOD2 (rs2076756, rs2066844, and rs2066845), IRGM (rs4958847 and rs13361189), and ATG16L1 (rs2241880). RESULTS: There were 86 ileocolectomies of 287 (30%) with complications requiring intervention. The single nucleotide polymorphism rs13361189 in the gene IRGM was significantly associated with complications on univariate and multivariate analysis. There were 61 patients with a variant at the rs13361189 single nucleotide polymorphism and 26 of them had complications, although only 55 of the 208 wild-type patients had complications (43% vs 26%; OR = 2.1; p = 0.02). Other significant factors associated with complication after ileocolectomy were open surgery, placement of a proximal ileostomy, and a greater perioperative decrease in hematocrit. LIMITATIONS: This study was limited by its retrospective design and inherent selection bias. CONCLUSIONS: In addition to clinical risk factors, the rs13361189 single nucleotide polymorphism in the IRGM gene was independently associated with complications after ileocolectomy for Crohn's disease. The use of such genetic determinants may identify patients at increased risk for surgical complications after ileocolectomy. See Video Abstract at http://links.lww.com/DCR/B124. FACTORES CLÍNICOS Y GENÉTICOS ASOCIADOS CON COMPLICACIONES DESPUÉS DE LA ILEOCOLECTOMÍA DE CROHN: La ileocolectomía es la cirugía más común realizada para la enfermedad de Crohn y con frecuencia ocurren complicaciones postoperatorias. Ha habido una evaluación mínima de complicaciones después de la ileocolectomía, en función de factores clínicos y genéticos.Evaluar factores genéticos y clínicos asociados con complicaciones, después de la ileocolectomía por Crohn.Estudio retrospectivo de cohorte clínico y genético.Este estudio se realizó en un centro de atención terciaria de alto volumen.Identificamos a 269 pacientes con enfermedad de Crohn, sometidos a 287 ileocolectomías en nuestra institución, entre julio de 2008 y octubre de 2018.La asociación de complicaciones con una combinación de factores clínicos y seis polimorfismos de un solo nucleótido asociados a Crohn en NOD2 (rs2076756, rs2066844 y rs2066845), IRGM (rs4958847 y rs13361189) y ATG16L1 (rs2241880).Hubieron 86 ileocolectomías en 287 (30%) pacientes con complicaciones que requirieron intervención. El polimorfismo de un solo nucleótido rs13361189 en el gen IRGM se asoció significativamente con complicaciones en el análisis univariado y multivariado. Hubieron 61 pacientes con una variante en el polimorfismo de un solo nucleótido rs13361189 y 26 de ellos tuvieron complicaciones, mientras que solo 55 de los 208 pacientes de tipo salvaje (WT) tuvieron complicaciones (43% vs 26%, OR 2.1, p = 0.02). Otros factores significativos asociados con las complicaciones después de la ileocolectomía fueron, la cirugía abierta, la colocación de una ileostomía proximal y una mayor disminución perioperatoria del hematocrito.Este estudio estuvo limitado por su diseño retrospectivo y sesgo de selección inherente.Además de los factores de riesgo clínicos, el polimorfismo de un solo nucleótido rs13361189 en el gen IRGM se asoció independientemente con complicaciones después de la ileocolectomía, para la enfermedad de Crohn. El uso de tales determinantes genéticos puede identificar a los pacientes con mayor riesgo de complicaciones quirúrgicas, después de la ileocolectomía. Consulte Video Resumen en http://links.lww.com/DCR/B124.

Impact of the NaV1.8 variant, A1073V, on post-sigmoidectomy pain and electrophysiological function in rat sympathetic neurons.

NaV1.8 channels play a crucial role in regulating the action potential in nociceptive neurons. A single nucleotide polymorphism in the human NaV1.8 gene SCN10A, A1073V (rs6795970, G>A), has been linked to the diminution of mechanical pain sensation as well as cardiac conduction abnormalities. Furthermore, studies have suggested that this polymorphism may result in a "loss-of-function" phenotype. In the present study, we performed genomic analysis of A1073V polymorphism presence in a cohort of patients undergoing sigmoid colectomy who provided information regarding perioperative pain and analgesic use. Homozygous carriers reported significantly reduced severity in postoperative abdominal pain compared with heterozygous and wild-type carriers. Homozygotes also trended toward using less analgesic/opiates during the postoperative period. We also heterologously expressed the wild-type and A1073V variant in rat superior cervical ganglion neurons. Electrophysiological testing demonstrated that the mutant NaV1.8 channels activated at more depolarized potentials compared with wild-type channels. Our study revealed that postoperative abdominal pain is diminished in homozygous carriers of A1073V and that this is likely due to reduced transmission of action potentials in nociceptive neurons. Our findings reinforce the importance of NaV1.8 and the A1073V polymorphism to pain perception. This information could be used to develop new predictive tools to optimize patient pain experience and analgesic use in the perioperative setting.NEW & NOTEWORTHY We present evidence that in a cohort of patients undergoing sigmoid colectomy, those homozygous for the NaV1.8 polymorphism (rs6795970) reported significantly lower abdominal pain scores than individuals with the homozygous wild-type or heterozygous genotype. In vitro electrophysiological recordings also suggest that the mutant NaV1.8 channel activates at more depolarizing potentials than the wild-type Na+ channel, characteristic of hypoactivity. This is the first report linking the rs6795970 mutation with postoperative abdominal pain in humans.

Identification of a rare LAMB4 variant associated with familial diverticulitis through exome sequencing.

Diverticulitis is a chronic disease of the colon in which diverticuli, or outpouching through the colonic wall, become inflamed. Although recent observations suggest that genetic factors may play a significant role in diverticulitis, few genes have yet been implicated in disease pathogenesis and familial cases are uncommon. Here, we report results of whole exome sequencing performed on members from a single multi-generational family with early onset diverticulitis in order to identify a genetic component of the disease. We identified a rare single nucleotide variant in the laminin ß 4 gene (LAMB4) that segregated with disease in a dominant pattern and causes a damaging missense substitution (D435N). Targeted sequencing of LAMB4 in 148 non-familial and unrelated sporadic diverticulitis patients identified two additional rare variants in the gene. Immunohistochemistry indicated that LAMB4 localizes to the myenteric plexus of colonic tissue and patients harboring LAMB4 variants exhibited reduced LAMB4 protein levels relative to controls. Laminins are constituents of the extracellular matrix and play a major role in regulating the development and function of the enteric nervous system. Reduced LAMB4 levels may therefore alter innervation and morphology of the enteric nervous system, which may contribute to colonic dysmotility associated with diverticulitis.

Multifocal Versus Conventional Unifocal Diverticulitis: A Comparison of Clinical and Transcriptomic Characteristics.

BACKGROUND: The management of diverticulitis is compromised by difficulty in identifying patients who require surgery for recurrent or persistent disease. Here, we introduce the concept of multifocal diverticulitis (MFD), characterized by multiple episodes of diverticulitis occurring at different locations within the colon. AIMS: To compare clinical characteristics, success of surgical management, and colonic transcriptomes of MFD patients to patients with conventional unifocal diverticulitis (UFD). METHODS: This retrospective study included 404 patients with CT-confirmed diverticulitis episodes. Patients with diverticulitis seen in at least two different colonic locations were classified as the MFD group and compared to the UFD group based on number of episodes, sites of disease, family history, surgeries performed, and postoperative recurrence. RNA-seq was conducted on full-thickness colonic tissues of ten MFD and 11 UFD patients. RESULTS: Twenty-eight patients (6.9%) with MFD were identified. MFD patients had more diverticulitis episodes and were more likely to have positive family history, have right-sided disease, require surgery, and have recurrence after surgery. All MFD patients treated with segmental resection had recurrence, while recurrence was less common in patients undergoing more extensive surgery (P < 0.001). Using RNA-seq, we identified 69 genes that were differentially expressed between MFD and UFD patients. Significantly down-regulated genes were associated with immune response pathways. CONCLUSIONS: MFD appears to be a more severe subset of diverticulitis with a possible genetic component. Transcriptomic data suggest that MFD may be associated with alteration of the immune response.

RNA-seq implicates deregulation of the immune system in the pathogenesis of diverticulitis.

Individuals with diverticula or outpouchings of the colonic mucosa and submucosa through the colonic wall have diverticulosis, which is usually asymptomatic. In 10-25% of individuals, the diverticula become inflamed, resulting in diverticulitis. Very little is known about the pathophysiology or gene regulatory pathways involved in the development of diverticulitis. To identify these pathways, we deep sequenced RNAs isolated from full-thickness sections of sigmoid colon from diverticulitis patients and control individuals. Specifically for diverticulitis cases, we analyzed tissue adjacent to areas affected by chronic disease. Since the tissue was collected during elective sigmoid resection, the disease was in a quiescent state. A comparison of differentially expressed genes found that gene ontology (GO) pathways associated with the immune response were upregulated in diverticulitis patients compared with nondiverticulosis controls. Next, weighted gene coexpression network analysis was performed to identify the interaction among coexpressed genes. This analysis revealed RASAL3, SASH3, PTPRC, and INPP5D as hub genes within the brown module eigengene, which highly correlated (r = 0.67, P = 0.0004) with diverticulitis. Additionally, we identified elevated expression of downstream interacting genes. In summary, transcripts associated with the immune response were upregulated in adjacent tissue from the sigmoid colons of chronic, recurrent diverticulitis patients. Further elucidating the genetic or epigenetic mechanisms associated with these alterations can help identify those at risk for chronic disease and may assist in clinical decision management.NEW & NOTEWORTHY By using an unbiased approach to analyze transcripts expressed in unaffected colonic tissues adjacent to those affected by chronic diverticulitis, our study implicates that a defect in the immune response may be involved in the development of the disease. This finding expands on the current data that suggest the pathophysiology of diverticulitis is mediated by dietary, age, and obesity-related factors. Further characterizing the immunologic differences in diverticulitis may better inform clinical decision-making.

Development of a total colectomy and ileorectal anastomosis rat model to evaluate colonic metaplasia.

BACKGROUND: Ulcerative colitis is an idiopathic inflammatory condition of the colon that may require surgical intervention including proctocolectomy and either ileal pouch-anal anastomosis or in the pediatric population, low ileorectal anastomosis (IRA). Often, subsequent physiologic alteration (or colonic metaplasia) occurs in the anastomosed small bowel that includes changes in mucin content, villous blunting, and increased expression of WNT5A, a marker of colonic crypt regeneration. We developed a rat low IRA model to assess and study the development of colonic metaplasia. MATERIALS AND METHODS: We subjected male Sprague-Dawley rats (n = 17) to total colectomy and low IRA surgery and evaluated healing periodically by endoscopic evaluation. The ileum upstream of the anastomosis was assessed by hematoxylin and eosin staining, and the mucin content was measured by high iron diamine-Alcian blue staining. Wnt5a transcripts were quantified by reverse transcription and quantitative polymerase chain reaction at the 8-wk study end point. RESULTS: Although no gross endoscopic evidence of inflammation was seen throughout the course of the study, colonic metaplasia in the small bowel was detected in 7 out of 10 (70%) rats at the study end point. In rats with colonic metaplasia, enhanced expression of Wnt5a was evident at the study end point compared to levels in the terminal ileum at the time of surgery. CONCLUSIONS: Within 4-8 wk, the majority of rats subjected to IRA developed colonic metaplasia defined by villous blunting, changes in mucin content, and increased expression of Wnt5a. This model provides a method to study small bowel colonic metaplasia.

Diverticulitis and Crohn's disease have distinct but overlapping tumor necrosis superfamily 15 haplotypes.

BACKGROUND: Diverticulitis (DD) and Crohn's disease (CD) have overlapping features including bowel structuring, inflammation, and infection. Tumor necrosis superfamily 15 (TNFSF15) is an immunoregulatory, anti-angiogenic gene. CD has been previously associated with a haplotype of five TNFSF15 single-nucleotide polymorphism alleles: rs3810936 (G allele), rs6478108 (A), rs6478109 (G), rs7848647 (G), and rs7869487 (A). We aimed to determine the TNFSF15 risk haplotype for DD versus controls with a subgroup analysis of youthful DD patients (aged ≤55 y) versus older controls (aged ≥55 y). METHODS: A total of 148 diverticulitis patients (90 aged ≤55 y) and 200 controls (87 aged ≥55 y) were genotyped using our custom-designed Illumina Veracode microarray chip. Genotypes from rs3810936, rs6478108, rs6478109, rs7848647, rs7869487 and two additional TNFSF15 single nucleotide polymorphisms, rs3810936 and rs11554257, were analyzed. PHASE version 2.1, R with HaploStats and the Broad Institute's Haploview program were used for statistics and imputed haplotype frequency. Permutation corrected for multiple comparisons. RESULTS: The CD GAGGA haplotype was significantly associated with diverticulitis (P = 0.03) in the all DD versus all controls comparison. A second haplotype, rs6478108 (A), rs6478109 (G), rs7869487 (A), and rs4263839 (G), was also associated with DD in this cohort (P = 0.025). A third haplotype rs6478108 (A), rs6478109 (G), rs7848647 (G) and rs7869487 (A), rs4263839 (G) was demonstrated in the DD < 55 versus controls >55 comparison (P = 0.045). CONCLUSIONS: Distinct but overlapping TNFSF15 haplotypes were demonstrated in diverticulitis patients versus healthy controls when compared with the known Crohn's risk haplotype suggesting similar but distinct genetic predispositions. This study strengthens the role for a genetic predisposition to diverticulitis that involves the TNFSF15 gene.

A model for family-based case-control studies of genetic imprinting and epistasis.

Genetic imprinting, or called the parent-of-origin effect, has been recognized to play an important role in the formation and pathogenesis of human diseases. Although the epigenetic mechanisms that establish genetic imprinting have been a focus of many genetic studies, our knowledge about the number of imprinting genes and their chromosomal locations and interactions with other genes is still scarce, limiting precise inference of the genetic architecture of complex diseases. In this article, we present a statistical model for testing and estimating the effects of genetic imprinting on complex diseases using a commonly used case-control design with family structure. For each subject sampled from a case and control population, we not only genotype its own single nucleotide polymorphisms (SNPs) but also collect its parents' genotypes. By tracing the transmission pattern of SNP alleles from parental to offspring generation, the model allows the characterization of genetic imprinting effects based on Pearson tests of a 2 × 2 contingency table. The model is expanded to test the interactions between imprinting effects and additive, dominant and epistatic effects in a complex web of genetic interactions. Statistical properties of the model are investigated, and its practical usefulness is validated by a real data analysis. The model will provide a useful tool for genome-wide association studies aimed to elucidate the picture of genetic control over complex human diseases.

Higher Mortality in Surgically Managed Diverticulitis is Associated with Asian Ethnicity and Right-Sided Disease.

BACKGROUND: Although right-sided diverticulitis is perceived to have a higher incidence among Asians and infrequently requires surgical management in comparison with sigmoid diverticulitis, it is unknown whether differences in outcomes are due to ethnic disparity or disease pathophysiology. OBJECTIVE: The aim of this study was to determine the surgical outcomes for Asian and non-Asian patients with diverticulitis who underwent colectomy. DESIGN: Patients identifiable by ethnicity in the Nationwide Inpatient Sample with diverticulitis and colectomy between 2004 and 2010 were included. Univariate comparisons were made between Asian and non-Asian patients by using t tests for continuous variables and χ tests for categorical variables. Propensity score matching analysis was performed to compare Asian patients with otherwise similar non-Asian patients. PATIENTS: Included were 58,142 non-Asian and 335 Asian patients with diverticulitis who underwent a colectomy. MAIN OUTCOME MEASURES: The primary outcomes were in-hospital mortality, hospital length of stay, and total costs. RESULTS: Asian patients were younger (56.1 vs. 59.2 years, p < 0.0001), were more likely to undergo a right colectomy (22.7% vs. 4.1%, p < 0.0001), and were more likely to have emergent/urgent surgery than the non-Asian patients (67.1% vs. 49.8%, p < 0.0001). Without controlling for patient/disease factors, there were statistically significant differences in mortality (non-Asian 2.2% vs. Asian 4.2%; p = 0.014), length of stay (non-Asian 8.9 vs. Asian 9.8 days; p = 0.0166), and costs (non-Asian $18,783 vs. Asian $21,901; p = 0.001). Propensity score matching comparing 333 non-Asian patients with 333 similar Asian patients showed that, whereas differences in cost and length of stay became insignificant, the difference in mortality remained statistically significant. LIMITATIONS: The ethnicity variable was not uniformly collected by all states within the Nationwide Inpatient Sample database. CONCLUSIONS: Among patients undergoing a colectomy for diverticulitis, a higher mortality was observed in Asian patients and right-sided disease. Future longitudinal studies comparing the natural history and outcomes of management between right- and left-sided diverticulitis are necessary to investigate whether a true ethnic disparity exists.

Ulcerative Colitis Is Associated With an Increased Risk of Venous Thromboembolism in the Postoperative Period: The Results of a Matched Cohort Analysis.

OBJECTIVES: To determine the rates of venous thromboembolism (VTE) during admission and within 30 days of hospital discharge in inflammatory bowel (IBD) patients undergoing colonic resection using the ACS National Surgical Quality Improvement Project (NSQIP) database and to compare these rates to VTE rates in cohorts of patients undergoing colonic resection for several other colonic pathologies. BACKGROUND: High rates of VTE have been demonstrated in hospitalized IBD patients. However, rates of postdischarge VTE in IBD patients are understudied. METHODS: Demographic, operative, and outcomes data for 96,999 patients undergoing colonic resection for diverticulitis, colorectal cancer (CRC), benign neoplasms, ulcerative colitis (UC), and Crohn's disease (CD) between 2005 and 2011 was obtained. Student t and χ tests were used for univariate analysis. A logistic multivariate analysis was performed with all significant variables. Propensity score matching was utilized to compare the VTE incidences between the groups. RESULTS: Highest VTE risk was seen in obese patients [odds ratio (OR) = 1.41], those older than 73 years (OR = 1.58) and with bleeding disorders (OR = 1.44), American Society of Anesthesiology class III/IV (OR = 1.52/1.86), preoperative systemic inflammatory response syndrome (OR = 1.55), sepsis (OR = 1.48) or steroid use (OR = 1.63), and primary diagnosis of UC (OR = 2.10). The UC group had the highest incidence of VTE (2.74%), followed by CRC patients (1.74%). A 1.2% incidence was seen in the CD population, and 41.5% of the UC-VTEs were diagnosed after discharge. CONCLUSIONS: This study affirms that inpatient UC patients undergoing colonic resection are at high risk for VTE and suggests that this risk persists into the postdischarge period. Thus, these patients should be given appropriate prophylaxis.