The Relationship between Treatment Response and Overall Survival in Borderline, Non-Resectable and Resectable Pancreatic Cancer Patients Treated with Neoadjuvant FOLFIRINOX.

Background: The National Comprehensive Cancer Network (NCCN)-recommended treatment for patients with borderline-resectable pancreatic cancer (BRPC) and locally advanced pancreatic cancer (LAPC) involves a combination of neoadjuvant FOLFIRINOX chemotherapy and the curative surgical resection of the tumor. This study seeks to identify the clinical, radiological, laboratory, and pathologic predictors that can anticipate the oncological outcomes of patients. Methods: In this study, we conducted a retrospective analysis of patients who had undergone curative surgical resection for BRPC, LAPC, or resectable disease with high-risk features after receiving neoadjuvant FOLFIRINOX at two institutions. We evaluated by means of multivariate analysis whether clinical and laboratory response, tumor markers, radiological response, and pathologic tumor response grade correlated with overall survival (OS) and disease-free survival (DFS). Results: The study enrolled a total of 70 patients with BRPC, LAPC, and resectable disease with high-risk features who underwent resection after neoadjuvant FOLFIRINOX. Age above 65 years and fewer than nine cycles of chemotherapy (OR 4.2; 95% CI 1.4-12.0; p-value 0.007); locally advanced tumors after neoadjuvant treatment (NAT) (OR 7.0; 95% CI 1.9-25.7; p-value 0.003); and lymph node disease and histological tumor regression grade 2 and 3 (OR 4.3; 95% CI 0.9-19.2; p-value 0.05) were risk factors linked to adverse OS and DFS. The median OS and DFS were 33 (22-43.9) months and 16.5 (11.3-21.6) months, respectively. Conclusions: Classification as a LA tumor after NAT was the only preoperative radiological factor that predicted adverse survival in patients undergoing curative surgery after NAT. Other clinical, biochemical, and radiological measures of response were not found to predict OS. Patient age, the cumulative administration of more than eight cycles of chemotherapy, and a significant pathological response were associated with better OS. The results of this study are important for treatment decision-making and prognostication in patients with BRPC and LAPC.

The Yield of Routine Tissue Sampling in Pediatric Gastrointestinal Endoscopy.

OBJECTIVES: Societies' guidelines suggest routine tissue sampling in all children undergoing esophagogastroduodenoscopy and ileocolonoscopy, even in the absence of visible endoscopy abnormalities. We aimed to determine the agreement between endoscopic and histopathological findings in pediatric endoscopy and to assess the yield of routine biopsies from all sites. METHODS: Since January 2019, our endoscopy institute protocol has included routine biopsies sampling from the esophagus, stomach, duodenum, ileum, and colon in all diagnostic procedures. Agreement between tests was done using the kappa coefficient ( κ ). The study included all endoscopies performed during 2019. RESULTS: In total, 541 diagnostic endoscopies were done during the study period with 434 (80%) esophagogastroduodenoscopy and 107 (20%) were ileocolonoscopy. Compared to histology, endoscopic findings performance were: esophagus-sensitivity 33%, specificity 98%; stomach-sensitivity 60%, specificity 89%; duodenum-sensitivity 50%, specificity 97%; duodenal bulb-sensitivity 47%, specificity 89%; terminal ileum-sensitivity 82%, specificity 100%; colon-sensitivity 84%, specificity 96%. Assessment of concordance between endoscopic and histopathologic findings reveals an overall low level of agreement in esophagogastroduodenoscopy ( κ of 0.39, 0.51, 0.53, and 0.24 for the esophagus, stomach, duodenal second part, and bulb, respectively), and good agreement in ileocolonoscopy ( κ of 0.88 and 0.81 for the ileum and colon, respectively). CONCLUSIONS: Endoscopy findings are highly specific for histologic pathology, whereas the absence of findings correlates poorly with histologic findings. Ileocolonoscopy shows better agreement than esophagogastroduodenoscopy. Our data support routine tissue sampling in pediatric endoscopy.

Management of pouch related symptoms in patients who underwent ileal pouch anal anastomosis surgery for adenomatous polyposis.

BACKGROUND: Adenomatous polyposis syndromes (APS) patients with ileal pouch anal anastomosis (IPAA) suffer frequent symptoms with scarce signs of inflammation, distinct from ulcerative colitis patients. While the management of pouchitis in ulcerative colitis patients is well established, data regarding response to treatment modalities targeting pouch-related disorders in APS patient population is scarce. AIM: To assess clinical, endoscopic and histologic response to various treatment modalities employed in the therapy of pouch related disorders. METHODS: APS patients who underwent IPAA between 1987-2019 were followed every 6-12 mo and pouch-related symptoms were recorded at every visit. Lower endoscopy was performed annually, recording features of the pouch, cuff and terminal ileum. A dedicated gastrointestinal pathologist reviewed biopsies for signs and severity of inflammation. At current study, files were retrospectively reviewed for initiation and response to various treatment modalities between 2015-2019. Therapies included dietary modifications, probiotics, loperamide, antibiotics, bismuth subsalicylate, mebeverine hydrochloride, 5-aminosalicylic acid compounds and topical rectal steroids. Symptoms and endoscopic and histologic signs of inflammation before and after treatment were assessed. Pouchitis disease activity index (PDAI) and its subscores was calculated. Change of variables before and after therapy was assessed using Wilcoxon signed rank test for continuous variables and using McNemar's test for categorical variables. RESULTS: Thirty-three APS patients after IPAA were identified. Before treatment, 16 patients (48.4%) suffered from abdominal pain and 3 (9.1%) from bloody stools. Mean number of daily bowel movement was 10.3. Only 4 patients (12.1%) had a PDAI ≥ 7. Mean baseline PDAI was 2.5 ± 2.3. Overall, intervention was associated with symptomatic relief, mainly decreasing abdominal pain (from 48.4% to 27.2% of patients, P = 0.016). Daily bowel movements decreased from a mean of 10.3 to 9.3 (P = 0.003). Mean overall and clinical PDAI scores decreased from 2.58 to 1.94 (P = 0.016) and from 1.3 to 0.87 (P = 0.004), respectively. Analyzing each treatment modality separately, we observed that dietary modifications decreased abdominal pain (from 41.9% of patients to 19.35%, P = 0.016), daily bowel movements (from 10.5 to 9.3, P = 0.003), overall PDAI (from 2.46 to 2.03, P = 0.04) and clinical PDAI (1.33 to 0.86, P = 0.004). Probiotics effectively decreased daily bowel movements (from 10.2 to 8.8, P = 0.007), overall and clinical PDAI (from 2.9 to 2.1 and from 1.38 to 0.8, P = 0.032 and 0.01, respectively). While other therapies had minimal or no effects. No significant changes in endoscopic or histologic scores were seen with any therapy. CONCLUSION: APS patients benefit from dietary modifications and probiotics that improve their pouch-related symptoms but respond minimally to anti-inflammatory and antibiotic treatments. These results suggest a functional rather than inflammatory disorder.

Interleukin 23 Produced by Hepatic Monocyte-Derived Macrophages Is Essential for the Development of Murine Primary Biliary Cholangitis.

Background and Aims: Primary Biliary Cholangitis (PBC) is an organ-specific autoimmune liver disease. Mononuclear phagocytes (MNPs), comprise of monocyte, dendritic cells and monocyte-derived macrophages, constitute major arm of the innate immune system known to be involved in the pathogenesis of autoimmune disorders. MNPs were shown to accumulate around intra-hepatic bile ducts in livers of PBC patients. Interleukin 23 (IL-23) is a pro-inflammatory cytokine. IL-23-positive cells were detected in livers of patients with advanced stage PBC and IL-23 serum levels found to be in correlation with PBC disease severity. Our overall goal was to assess the importance of IL-23 derived from MNPs in PBC pathogenesis. Methods: We utilized an inducible murine model of PBC and took advantage of transgenic mice targeting expression of IL-23 by specific MNP populations. Analysis included liver histology assessment, flow cytometry of hepatic immune cells and hepatic cytokine profile evaluation. Specific MNPs sub-populations were sorted and assessed for IL-23 expression levels. Results: Flow cytometry analysis of non-parenchymal liver cells in autoimmune cholangitis revealed massive infiltration of the liver by MNPs and neutrophils and a decrease in Kupffer cells numbers. In addition, a 4-fold increase in the incidence of hepatic IL-17A producing CD4+ T cells was found to be associated with an increase in hepatic IL23-p19 and IL17A expression levels. Disease severity was significantly ameliorated in both CD11ccreP19flox/flox and CX3CR1creP19 flox/flox mice as assessed by reduced portal inflammation and decreased hepatic expression of various inflammatory cytokines. Amelioration of disease severity was associated with reduction in IL-17A producing CD4+ T cells percentages and decreased hepatic IL23-p19 and IL17A expression levels. qRT-PCR analysis of sorted hepatic MNPs demonstrated high expression levels of IL-23 mRNA specifically by CX3CR1hiCD11c+ monocyte-derived macrophages. Conclusion: Our results indicate a major role for IL-23 produced by hepatic monocyte-derived macrophages in the pathogenesis of PBC. These results may pave the road for the development of new immune-based and cell specific therapeutic modalities for PBC patients not responding to current therapies.

Integrase-derived peptides together with CD24-targeted lentiviral particles inhibit the growth of CD24 expressing cancer cells.

The integration of viral DNA into the host genome is mediated by viral integrase, resulting in the accumulation of double-strand breaks. Integrase-derived peptides (INS and INR) increase the number of integration events, leading to escalated genomic instability that induces apoptosis. CD24 is a surface protein expressed mostly in cancer cells and is very rarely found in normal cells. Here, we propose a novel targeted cancer therapeutic platform based on the lentiviral integrase, stimulated by integrase-derived peptides, that are specifically delivered to cancerous cells via CD24 antigen-antibody targeting. INS and INR were synthesized and humanized and anti-CD24 antibodies were fused to the lentivirus envelope. The activity, permeability, stability, solubility, and toxicity of these components were analyzed. Cell death was measured by fluorescent microscopy and enzymatic assays and potency were tested in vitro and in vivo. Lentivirus particles, containing non-functional DNA led to massive cell death (40-70%). Raltegravir, an antiretroviral drug, inhibited the induction of apoptosis. In vivo, single and repeated administrations of INS/INR were well tolerated without any adverse effects. Tumor development in nude mice was significantly inhibited (by 50%) as compared to the vehicle arm. In summary, a novel and generic therapeutic platform for selective cancer cell eradication with excellent efficacy and safety are presented.

Micro-RNA Expression Patterns Predict Metastatic Spread in Solid Pseudopapillary Neoplasms of the Pancreas.

Solid pseudopapillary neoplasm (SPN) of pancreas is a rare pancreatic neoplasm with a low metastatic potential. Up to 10% of patients with localized disease at presentation will develop systemic metastases, usually in the peritoneum or the liver. Due to the rarity of SPNs and the overall excellent prognosis, reliable prognostic factors to predict malignant biological behavior remain undetermined. Therefore, we aimed to define clinical, histological, and microRNA patterns that are associated with metastatic disease. We conducted a retrospective single center study on all patients operated for SPN of pancreas between 1995 and 2018. Clinical and pathological data were collected, and expression patterns of 2,578 human microRNAs were analyzed using microRNA array (Affimetrix 4.1) in normal pancreases (NPs), localized tumors (LTs), and metastatic tumors (MTs). The diagnosis of SPN was confirmed in 35 patients who included 28 females and 3 males, with a mean age of 33.8 ± 13.9 years. The only clinical factor associated with metastases was tumor size (mean tumor size 5.20 ± 3.78 in LT vs. 8.13± 1.03 in MT, p < 0.012). Microscopic features of malignancy were not associated with metastases, nor were immunohistochemical stains, including the proliferative index KI67. Higher expressions of miR-184, miR-10a, and miR-887, and lower expressions of miR-375, miR-217, and miR-200c were observed in metastatic tissues on microarray, and validated by real-time polymerase chain reaction. Hierarchal clustering demonstrated that the microRNA expression pattern of MTs was significantly different from that of LTs. The only clinical factor associated with metastases of SPN of pancreas was tumor size. Histological features and immunohistological staining were not predictive of metastases. A panel of six microRNAs was differentially expressed in MTs, and these findings could potentially be used to predict tumor behavior. Validation of these results is needed in larger series.

Increased Rate of Complete Pathologic Response After Neoadjuvant FOLFIRINOX for BRCA Mutation Carriers with Borderline Resectable Pancreatic Cancer.

BACKGROUND: Neoadjuvant FOLFIRINOX is a standard-of-care treatment for BRPC patients. Patients with gBRCAm who have demonstrated improved response to platinum-based chemotherapy may have impaired homologous repair deficiency. This study aimed to describe the pathologic complete response rate and long-term survival for patients with germline BRCA1 or BRCA2 mutation (gBRCAm) and borderline resectable pancreatic cancer (BRPC) treated with neoadjuvant FOLFIRINOX. METHODS: A dual-center retrospective analysis was performed. Patients who had BRPC treated with neoadjuvant FOLFIRINOX followed by curative resection were identified from clinical databases. Pathologic complete response was defined as no viable tumor cells present in the specimen. Common founder Jewish germline BRCA1 or BRCA2 mutation was determined for available patients. RESULTS: The 61 BRPC patients in this study underwent resection after neoadjuvant FOLFIRINOX. Analysis of BRCA mutation was performed for 39 patients, and 9 patients were found to be BRCA2 germline mutation carriers. The pathologic complete response rate was 44.4% for the gBRCAm patients and 10% for the BRCA non-carriers (p = 0.009). The median disease-free survival was not reached for the gBRCAm patients and was 7 months for the BRCA non-carriers (p = 0.03). The median overall survival was not reached for the gBRCAm patients and was 32 months for the BRCA non-carriers (p = 0.2). After a mean follow-up period of 33.7 months, all eight patients with pathologic complete response were disease-free. CONCLUSIONS: The study showed that gBRCAm patients with BRPC have an increased chance for pathologic complete response and prolonged survival after neoadjuvant FOLFIRINOX. The results support the benefit of exposing gBRCAm patients to platinum-based chemotherapy early in the course of the disease. Neoadjuvant FOLFIRINOX should be considered for BRCA carriers who have resectable pancreatic cancer.

LOXL2 Inhibition Paves the Way for Macrophage-Mediated Collagen Degradation in Liver Fibrosis.

Liver fibrosis is characterized by the excessive accumulation of extracellular matrix (ECM) proteins and enzymes, especially fibrillary collagens, and represents a major cause of morbidity and mortality worldwide. Lysyl oxidases (LOXs) drive covalent crosslinking of collagen fibers, thereby promoting stabilization and accumulation of liver fibrosis while limiting its resolution. Here we show in a carbon tetrachloride (CCl4)-induced liver fibrosis murine model that treatment with a novel anti-lysyl oxidase like 2 (LOXL2) neutralizing antibody, which targets extracellular LOXL2, significantly improves fibrosis resolution. LOXL2 inhibition following the onset of fibrosis accelerated and augmented collagen degradation. This was accompanied by increased localization of reparative monocyte-derived macrophages (MoMFs) in the proximity of fibrotic fibers and their representation in the liver. These cells secreted collagenolytic matrix metalloproteinases (MMPs) and, in particular, the membrane-bound MT1-MMP (MMP-14) collagenase. Inducible and selective ablation of infiltrating MoMFs negated the increased "on-fiber" accumulation of MMP-14-expressing MoMFs and the accelerated collagenolytic activity observed in the anti-LOXL2-treated mice. Many studies of liver fibrosis focus on preventing the progression of the fibrotic process. In contrast, the therapeutic mechanism of LOXL2 inhibition presented herein aims at reversing existing fibrosis and facilitating endogenous liver regeneration by paving the way for collagenolytic macrophages.

Resorting the function of the colorectal cancer gatekeeper adenomatous polyposis coli.

As a large number of cancers are caused by nonsense mutations in key genes, read-through of these mutations to restore full-length protein expression is a potential therapeutic strategy. Mutations in the adenomatous polyposis coli (APC) gene initiate the majority of both sporadic and hereditary colorectal cancers (CRC) and around 30% of these mutations are nonsense mutations. Our goal was to test the feasibility and effectiveness of APC nonsense mutation read-through as a potential chemo-preventive therapy in Familial Adenomatous Polyposis (FAP), an inherited CRC syndrome patients. Ten FAP patients harboring APC nonsense mutations were treated with the read-through inducing antibiotic erythromycin for 4 months. Endoscopic assessment of the adenomas was performed at baseline, after 4 and after 12 months. Adenoma burden was documented in terms of adenoma number, maximal polyp size and cumulative polyp size per procedure. Tissue samples were collected and subjected to molecular and genetic analyses. Our results show that in the majority of patients the treatment led to a decrease in cumulative adenoma burden, median reduction in cumulative adenoma size and median reduction in adenoma number. Molecular and genetic analyses of the adenomas revealed that the treatment led to a reduced number of somatic APC mutations, reduced cellular proliferation and restoration of APC tumor-suppressing activity. Together, our findings show that induced read-through of APC nonsense mutations leads to promising clinical results and should be further investigated to establish its therapeutic potential in FAP and sporadic CRCs harboring nonsense APC mutations.

Tumor-to-Tumor Metastasis of Colorectal Adenocarcinoma to Ovarian Cystadenofibroma: A Case Report and Review of the Literature.

Tumor-to-tumor metastasis is being described in different types of tumors and in increasing amount of cases. Being aware of this phenomenon is important, as it affects disease stage and treatment approach. In this report, we descried an incidental histopathologic finding of metastatic adenocarcinoma to an ovarian cystadenofibroma and review cases published previously in the literature.

Resection Versus Observation of Small Asymptomatic Nonfunctioning Pancreatic Neuroendocrine Tumors.

BACKGROUND: Management of asymptomatic, nonfunctioning small pancreatic neuroendocrine tumors (PNETs) is controversial because of their overall good prognosis, and the morbidity and mortality associated with pancreatic surgery. Our aim was to compare the outcomes of resection with expectant management of patients with small asymptomatic PNETs. METHODS: Retrospective review of patients with nonfunctioning asymptomatic PNETs < 2 cm that underwent resection or expectant management at the Tel-Aviv Medical Center between 2001 and 2018. RESULTS: Forty-four patients with small asymptomatic, biopsy-proven low-grade PNETs with a KI67 proliferative index < 3% were observed for a mean of 52.48 months. Gallium67DOTATOC-PET scan was completed in 32 patients and demonstrated uptake in the pancreatic tumor in 25 (78%). No patient developed systemic metastases. Two patients underwent resection due to tumor growth, and true tumor enlargement was evidenced in final pathology in one of them. Fifty-five patients underwent immediate resection. Significant complications (Clavien-Dindo grade ≥ 3) developed in 10 patients (18%), mostly due to pancreatic leak, and led to one mortality (1.8%). Pathological evaluation revealed lymphovascular invasion in 1 patient, lymph node metastases in none, and a Ki67 index ≥ 3% in 5. No case of tumor recurrence was diagnosed after mean follow-up of 52.8 months. CONCLUSIONS: No patients with asymptomatic low-grade small PNETs treated by expectant management were diagnosed with regional or systemic metastases after a 52.8-month follow-up. Local tumor progression rate was 2.1%. Surgery has excellent long-term outcomes, but it harbors significant morbidity and mortality. Observation can be considered for selected patients with asymptomatic, small, low grade PNETs.

Activated Eosinophils Exert Antitumorigenic Activities in Colorectal Cancer.

Immunotherapies targeting T lymphocytes are revolutionizing cancer therapy but only benefit a subset of patients, especially in colorectal cancer. Thus, additional insight into the tumor microenvironment (TME) is required. Eosinophils are bone marrow-derived cells that have been largely studied in the context of allergic diseases and parasite infections. Although tumor-associated eosinophilia has been described in various solid tumors including colorectal cancer, knowledge is still missing regarding eosinophil activities and even the basic question of whether the TME promotes eosinophil recruitment without additional manipulation (e.g., immunotherapy) is unclear. Herein, we report that eosinophils are recruited into developing tumors during induction of inflammation-induced colorectal cancer and in mice with the Apcmin /+ genotype, which develop spontaneous intestinal adenomas. Using adoptive transfer and cytokine neutralization experiments, we demonstrate that the TME supported prolonged eosinophil survival independent of IL5, an eosinophil survival cytokine. Tumor-infiltrating eosinophils consisted of degranulating eosinophils and were essential for tumor rejection independently of CD8+ T cells. Transcriptome and proteomic analysis revealed an IFNγ-linked signature for intratumoral eosinophils that was different from that of macrophages. Our data establish antitumorigenic roles for eosinophils in colorectal cancer. These findings may facilitate the development of pharmacologic treatments that could unleash antitumor responses by eosinophils, especially in colorectal cancer patients displaying eosinophilia.

Neoadjuvant FOLFIRINOX for locally advanced and borderline resectable pancreatic cancer: An intention to treat analysis.

OBJECTIVE: To assess clinical and pathologic efficacy of neoadjuvant FOLFIRINOX for locally advanced (LAPC) and borderline resectable pancreatic cancer (BRPC). METHODS: Patients receiving neoadjuvant FOLFIRINOX for LAPC and BRPC treated between 2014 and 2017 were identified. Post-treatment patients achieving resectability were referred for surgery, whereas unresectable patients continued chemotherapy. Clinical and pathological data were retrospectively compared with control group consisting of 47 consecutive patients with BRPC undergoing pancreatic and portal vein resection between 2008 and 2017. RESULTS: Thirty LAPC and 23 BRPC patients were identified. Reasons for unresectability included disease progression (70%), locally unresectable disease (18%), and poor performance status (11%). Three patients (10%) with LAPC, and 20 (87%) with BRPC underwent curative surgery. Compared with control group, perioperative complication rate (4.3% versus 28.9%, p = 0.016), and pancreatic fistula rate (0 versus 14.8%, p = 0.08) were lower. Peripancreatic fat invasion (52.2% vs 97.8%, p = 0.001), lymph node involvement (22% vs 54.3%, p = 0.01), and surgical margin involvement (0 vs 17.4%, p = 0.04) were higher in the control group. Median survival was 34.3 months in BRPC patients operated after FOLFIRINOX and 26.1 months in the control group (p = 0.07). Three patients (13%) with complete pathological response are disease-free after mean follow-up of 19 months. CONCLUSIONS: Whereas neoadjuvant FOLFIRINOX rarely achieves resectability in patients with LAPC (10%), most BRPC undergo resection (87%). Neoadjuvant FOLFIRINOX leads to complete pathological response in 13% of cases, tumor downstaging, and a trend towards improved survival compared with patients undergoing up-front surgery.

The Critical Role of Chemokine (C-C Motif) Receptor 2-Positive Monocytes in Autoimmune Cholangitis.

The therapy of primary biliary cholangitis (PBC) has lagged behind other autoimmune diseases despite significant improvements in our understanding of both immunological and molecular events that lead to loss of tolerance to the E2 component of pyruvate dehydrogenase, the immunodominant autoepitope of PBC. It is well known that Ly6Chi monocytes are innate immune cells infiltrating inflammatory sites that are dependent on the expression of C-C motif chemokine receptor 2 (CCR2) for emigration from bone marrow. Importantly, humans with PBC have a circulating monocyte pro-inflammatory phenotype with macrophage accumulation in portal tracts. We have taken advantage of an inducible chemical xenobiotic model of PBC and recapitulated the massive infiltration of monocytes to portal areas. To determine the clinical significance, we immunized both CCR2-deficient mice and controls with 2OA-BSA and noted that CCR2 deficiency is protective for the development of autoimmune cholangitis. Importantly, because of the therapeutic potential, we focused on inhibiting monocyte infiltration through the use of cenicriviroc (CVC), a dual chemokine receptor CCR2/CCR5 antagonist shown to be safe in human trials. Importantly, treatment with CVC resulted in amelioration of all aspects of disease severity including serum total bile acids, histological severity score, and fibrosis stage. In conclusion, our results indicate a major role for Ly6Chi monocytes and for CCR2 in PBC pathogenesis and suggest that inhibition of this axis by CVC should be explored in humans through the use of clinical trials.

Neutrophil extracellular traps in pediatric inflammatory bowel disease.

Neutrophil extracellular traps (NETs) are fibers composed of chromatin and neutrophil proteins released by activated neutrophils. NETs trap and kill microbes, activate dendritic and T cells, and are implicated in autoimmune and vascular diseases. The pathogenesis of inflammatory bowel disease (IBD) is multifactorial and characterized by chronic active mucosal inflammation with controversial contribution of neutrophils. Our aim is to describe the involvement of NETs in pediatric IBD. We retrospectively examined biopsies from the small bowel and colon of children at diagnosis of Crohn's disease (CD) or ulcerative colitis (UC). The biopsies were labeled for neutrophil elastase, myeloperoxidase, DNA, chromatin and histones in order to identify NETs. Samples of two children with normal colonoscopy served as controls. Twelve patients (5 boys) were included, 6 with CD and 6 with UC. Their average age was 12.2 years (range 5-16). NETs were found in all samples from patients and not in the samples from the two controls. This is the first demonstration of the presence of NETs in biopsies taken from the small bowel and colon of pediatric patients with IBD. More studies are needed in order to identify the role of NETs in CD/UC pathogenesis.

Gene expression alterations in ulcerative colitis patients after restorative proctocolectomy extend to the small bowel proximal to the pouch.

OBJECTIVES: To evaluate molecular profiles in the small bowel (SB) mucosa proximal to the pouch in ulcerative colitis (UC) patients after pouch surgery. DESIGN: Patients were prospectively recruited and stratified according to disease behaviour: normal pouch (NP), chronic pouchitis (CP), and Crohn's-like disease of the pouch (CLDP). Biopsies obtained from the pouch and the normal-appearing proximal SB (40 cm proximal to the anal verge) were compared to ileal biopsies from normal controls (NC). A histopathological score based on the degree of polymorphonuclear and mononuclear infiltrates was used to assess inflammation in the pouch and the proximal SB. Gene expression analysis was performed using microarrays, and validated by real-time PCR. Gene ontology and clustering were evaluated by bioinformatics. RESULTS: Thirty-six subjects were recruited (age 18-71 years, 16 males). Histopathology scores demonstrated minimal differences in the normal-appearing proximal SB of all groups. Nonetheless, significant (fold change ≥2, corrected p [FDR] ≤ 0.05) molecular alterations in the proximal SB were detected in all groups (NP n=9; CP n=80; and CLDP n=230) compared with NC. The magnitude of DUOX2 alteration in the proximal SB was highest. An increase of 6.0, 9.8 and 21.7 folds in DUOX2 expression in NP, CP, CLDP, respectively was observed. This was followed by alterations in MMP1, SLC6A14 and PGC. Gene alterations in the proximal SB overlapped with alterations within the pouch (76% and 97% overlap in CP and CLDP, respectively). Gene ontology analysis in the proximal SB and pouch were comparable. CONCLUSIONS: Significant gene expression alterations exist in an apparently unaffected proximal SB. Alterations in the pouch and the proximal SB were comparable, suggesting that inflammation may not be limited to the pouch, but that it extends to the proximal SB.

Human intestinal epithelial cells respond to ß-glucans via Dectin-1 and Syk.

Intestinal epithelial cells (IECs) are the first to encounter luminal antigens and may be involved in intestinal immune responses. Fungi are important components of the intestinal microflora. The potential role of fungi, and in particular their cell wall component ß-glucan, in modulating human intestinal epithelial responses is still unclear. Here we examined whether human IECs are capable of recognizing and responding to ß-glucans, and the potential mechanisms of their activation. We show that human IECs freshly isolated from surgical specimens, and the human IEC lines HT-29 and SW480, express the ß-glucan receptor Dectin-1. The ß-glucan-consisting glycans curdlan and zymosan stimulated IL-8 and CCL2 secretion by IEC lines. This was significantly inhibited by a Dectin-1 blockade using its soluble antagonist laminarin. Spleen tyrosine kinase (Syk), a signaling mediator of Dectin-1 activation, is expressed in human IECs. ß-glucans and Candida albicans induced Syk phosphorylation, and Syk inhibition significantly decreased ß-glucan-induced chemokine secretion from IECs. Thus, IECs may respond to ß-glucans by the secretion of pro-inflammatory chemokines in a Dectin-1- and Syk-dependent pathway, via receptors and a signaling pathway described to date only for myeloid cells. These findings highlight the importance of fungi-IEC interactions in intestinal inflammation.

Infiltrating monocyte-derived macrophages and resident kupffer cells display different ontogeny and functions in acute liver injury.

The liver has a remarkable capacity to regenerate after injury; yet, the role of macrophages (MF) in this process remains controversial mainly due to difficulties in distinguishing between different MF subsets. In this study, we used a murine model of acute liver injury induced by overdose of N-acetyl-p-aminophenol (APAP) and defined three distinct MF subsets that populate the liver following injury. Accordingly, resident Kupffer cells (KC) were significantly reduced upon APAP challenge and started recovering by self-renewal at resolution phase without contribution of circulating Ly6C(hi) monocytes. The latter were recruited in a CCR2- and M-CSF-mediated pathway at the necroinflammatory phase and differentiated into ephemeral Ly6C(lo) MF subset at resolution phase. Moreover, their inducible ablation resulted in impaired recovery. Microarray-based molecular profiling uncovered high similarity between steady-state KC and those recovered at the resolution phase. In contrast, KC and monocyte-derived MF displayed distinct prorestorative genetic signature at the resolution phase. Finally, we show that infiltrating monocytes acquire a prorestorative polarization manifested by unique expression of proangiogenesis mediators and genes involved with inhibition of neutrophil activity and recruitment and promotion of their clearance. Collectively, our results present a novel phenotypic, ontogenic, and molecular definition of liver-MF compartment following acute injury.