Abstract 1251: Novel potential role of m6A-demethylase FTO (fat mass and obesity) protein in colorectal cancer

Colorectal cancer (CRC) is the one of the most frequent and deadly cancer worldwide. The regulation mediated by the N6methyladenosine (m6A) demethylase protein called FTO in CRC is quite controversial. As previously studied in obesity and food intake, currently is being linked to stemness, epithelial-mesenchymal transition, chemotherapy resistance and proliferation in colon cancer cells, however, its localization and function in the tumor microenvironment (TME) and how it connects with progression remains unclear. The aim of this study was to evaluate FTO protein in tumor and healthy corresponding tissue from 22 colorectal cancer patients with different histological TNM stages (hTNM) by immunohistochemistry and multiple immunofluorescence analysis; classifying the tumor and stromal FTO localization and associating this data with clinical and histopathological features. As for content, the frequency of FTO+ cells in stromal compartments increases in more invasive stages compared to non-tumor tissue and in tumors with low desmoplasia. Regarding to localization, FTO is mostly nuclear and present in the lamina propria cells in non-tumor tissues and in immune and fibro-immune compartments in the TME, such as T cells, cancer associated fibroblasts and macrophages. In tumor cells, the percentage of FTO+ cells increase in early carcinogenic stages (hTNM I vs healthy tissue) and in moderately differentiated tumors. In addition, nuclear FTO expression increases in normal T cells and fibroblasts with a particular pattern after exposure for 24h to a colon adenocarcinoma cell-derived conditioned media, suggesting FTO activity in the TME interaction following a paracrine signal. In conclusion, the increase of the FTO protein in both tumor and stroma from CRC suggests its participation mediating TME communication.

Citation Format: Glauben T. Landskron-Ramos, Antonia L. Domínguez-Beltrando, Mauricio Zambra-Rojas, Antonella Sanguineti, Gonzalo Vasquez, Marjorie De la Fuente, Daniela Simian, Silvana Valdebenito-Silva, Juan Saavedra, Solange Gouet, Ricardo Soto-Rifo, Daniela Sauma, Eliseo Eugenin, Mario Abedrapo, Marcela A. Hermoso, Marcela A. Hermoso. Novel potential role of m6A-demethylase FTO (fat mass and obesity) protein in colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1251.

Implementation of a re-linkage to care strategy in patients with chronic hepatitis C who were lost to follow-up in Latin America

To achieve WHO's goal of eliminating hepatitis C virus (HCV), innovative strategies must be designed to diagnose and treat more patients. Therefore, we aimed to describe an implementation strategy to identify patients with HCV who were lost to follow-up (LTFU) and offer them re-linkage to HCV care. We conducted an implementation study utilizing a strategy to contact patients with HCV who were not under regular follow-up in 13 countries from Latin America. Patients with HCV were identified by the international classification of diseases (ICD-9/10) or equivalent. Medical records were then reviewed to confirm the diagnosis of chronic HCV infection defined by anti-HCV+ and detectable HCV-RNA. Identified patients who were not under follow-up by a liver specialist were contacted by telephone or email, and offered a medical reevaluation. A total of 10,364 patients were classified to have HCV. After reviewing their medical charts, 1349 (13%) had undetectable HCV-RNA or were wrongly coded. Overall, 9015 (86.9%) individuals were identified with chronic HCV infection. A total of 5096 (56.5%) patients were under routine HCV care and 3919 (43.5%) had been LTFU. We were able to contact 1617 (41.3%) of the 3919 patients who were LTFU at the primary medical institution, of which 427 (26.4%) were cured at a different institutions or were dead. Of the remaining patients, 906 (76.1%) were candidates for retrieval. In our cohort, about one out of four patients with chronic HCV who were LTFU were candidates to receive treatment. This strategy has the potential to be effective, accessible and significantly impacts on the HCV care cascade.

[Cholangiocarcinoma and combined hepatocellular-cholangiocarcinoma in cirrhotic patients]

BACKGROUND

Cholangiocarcinoma (CCA) is a primary hepatic tumor, frequently found in patients with liver cirrhosis and biliary tract diseases. Its varieties include isolated CCA or "combined hepatocellular-cholangiocarcinoma" (cHCC-CCA). The latter is uncommon, with poorly defined diagnostic criteria and natural history.

AIM

To characterize patients with cirrhosis with a pathological diagnosis of CCA and cHCC-CCA.

MATERIAL AND METHODS

Forty-nine liver biopsies with a pathological diagnosis of CCA were reviewed. The clinical records of patients were reviewed to fetch demographic variables, etiology of cirrhosis and clinical presentation.

RESULTS

Eight of the 49 patients had cirrhosis (16% of CCA biopsies reviewed). Their median age was 64 (27-71) years and five were females. Four patients had CCA, three patients cHCC-CCA and one had a bifocal tumor. Patients in the CCA group were more commonly symptomatic. Alpha-fetoprotein and CA 19-9 levels were elevated in one of eight and four of six patients, respectively. Within 12 months from diagnosis, five of eight patients died.

CONCLUSIONS

In most of these cases, the diagnosis of cHCC-CCA and CCA was made in the liver explant study without previous imaging diagnosis. This reinforces the usefulness of the histological study, in specific cases, prior to liver transplantation and emphasizes the importance of systematic explant exploration in these cases.

Pancreatic steatosis: A frequent finding in a Chilean population

INTRODUCTION AND AIMS

Pancreatic steatosis is an incidental radiologic finding in asymptomatic patients, and its clinical importance is unclear. Primary aim: to study the prevalence of pancreatic steatosis (PS) in consecutive patients registered at our hospital, that underwent computed axial tomography (CAT) scanning of the abdomen and pelvis, excluding known pancreatic diseases. Secondary aim: to review the association of PS with the demographic and clinical data of the patients, as well as with hepatic steatosis (HS).

MATERIALS AND METHODS

An observational study was conducted on adult patients that had CAT scans of the abdomen and pelvis.

DEFINITIONS

a) tissue density was measured in Hounsfield units (HU) in five 1 cm² areas of the pancreas, three areas of the spleen, and in segments VI and VII of the liver; b) fatty pancreas: a difference < -10 HU between the mean pancreas and mean spleen densities; and c) fatty liver: density < 40 HU. We registered the epidemiologic and laboratory data of the patients. The association of those factors with the presence of PS was analyzed using SPSS version 24.0 software, and statistical significance was set at a p < 0.05.

RESULTS

Of the 203 patients, PS was found in 61 (30%). The patients with PS were significantly older and had a higher body mass index. We found no significant association with the rest of the parameters studied, nor with HS (55 patients). None of the patients had symptoms attributable to a disease of the exocrine pancreas.

CONCLUSIONS

Fatty infiltration of the pancreas is a frequent finding in CAT scans, and its clinical importance is unclear. Aging of the population and the increase in obesity underline the need for future studies on PS.

Clinical characteristics and predictors of hospitalization among 7,108 ambulatory patients with positive RT-PCR for SARS-CoV-2 during the acute pandemic period

Objective:

To describe baseline characteristics of outpatients with a positive RT-PCR for SARS-CoV-2 and to define whether “red flags” (new-onset fever, dyspnea, and chest pain) can predict clinical worsening during the isolation period.

Methods:

This was an epidemiological, observational, descriptive study. Between March and September of 2020, all outpatients who tested positive for SARS-CoV-2 at a tertiary medical center located in Santiago de Chile were included. Demographic variables, comorbidities, red flags, and other symptoms were compiled using follow-up surveys at specific time points. The risk of clinical worsening (hospitalization) and adjusted hazard ratios (HRs) were calculated.

Results:

A total of 7,108 patients were included. The median age was 38 years (range, 0-101), and 52% were men. At baseline, 77% of the patients reported having characteristic symptoms of SARS-CoV-2 infection. The most prevalent onset symptoms were headache (53%), myalgia (47%), and fever (33%). According to the follow-up surveys, the incidence of symptoms decreased during the isolation period; however, 28% of the patients still presented with symptoms on day 14. The risk of hospitalization for patients with new-onset fever and dyspnea during the follow-up period was HR = 7.43 (95% CI, 3.85-14.3, p<0.01) and HR = 5.27 (95% CI, 1.52-18.30; p < 0.01 for both), respectively. New-onset chest pain showed no association with clinical worsening.

Conclusions:

In this sample of outpatients with a recent diagnosis of SARS-CoV-2 infection, a survey-based monitoring of symptoms was useful to identify those at risk of clinical worsening. New-onset fever and dyspnea during the isolation period were considered as red flags associated with clinical worsening and warrants prompt medical evaluation.

Severe Acute Respiratory Syndrome Coronavirus 2 Antibody Prevalence in Blood in a Large School Community Subject to a Coronavirus Disease 2019 Outbreak: A Cross-sectional Study

Background

A SARS-CoV-2 outbreak affecting 52 people from a large school community in Santiago, Chile was identified (March 12), nine days after the first country case. We assessed the magnitude of the outbreak and the role students and staff played using a self-administered antibody detection test and survey.

Methods

The school was closed on March 13, and the entire community was placed under quarantine. We implemented a home-delivery, self-administered, IgG/IgM antibody test and survey to a classroom stratified sample of students and all staff from May 4-19. We aimed to determine overall seroprevalence rates by age group, reported symptoms, contact exposure and to explore dynamics of transmission.

Results

Antibody positivity rates were 9.9% (95%CI: 8.2-11.8) for 1,009 students and 16.6% (95%CI: 12.1-21.9) for 235 staff. Among students, positivity was associated with younger age (P=0.01), lower grade level (P=0.05), prior RT-PCR positivity (P=0.03), and history of contact with a confirmed case (P<0.001). Among staff, positivity was higher in teachers (P=0.01) and in those previously RT-PCR positive (P<0.001). Excluding RT-PCR positive individuals, antibody positivity was associated with fever in adults and children (P=0.02; P=0.002), abdominal pain in children (P=0.001), and chest pain in adults (P=0.02). Within antibody positive individuals, 40% of students and 18% of staff reported no symptoms (P=0.01).

Conclusions

Teachers were more affected during the outbreak and younger children were at higher infection risk, likely because index case(s) were teachers and/or parents from preschool. Self-administered antibody testing, supervised remotely, proved to be a suitable and rapid tool. Our study provides useful information for school re-openings.

Are patients with inflammatory bowel disease receiving adequate immunisation?

INTRODUCTION

Inflammatory Bowel Disease (IBD) treatment may increase the risk of infections. Vaccines are part of the comprehensive IBD patient care. The aim of this study was to describe indications and adherence of immunizations in IBD and identify possible associated factors.

METHODS

A cross-sectional, analytic study was conducted in patients from an IBD Program of a tertiary center in Chile, between April - June 2019. Patients were asked to answer a vaccine survey and information also was obtained from the National Immunization Registry. Descriptive and association statistic were used (χ²; p<0.05).

RESULTS

A total of 243 patients were included (148 ulcerative colitis (UC), 86 Crohn's disease (CD) and 9 non-classifiable IBD). Only six patients (2%) of IBD patients received a complete immunization schedule. The highest vaccine rates were against influenza (67%), hepatitis B virus (40%), 13-valent pneumococcal (34%) and 23-polysaccharide pneumococcal (16%). The influenza vaccine rate has significantly increased, reaching 67% in 2019. The survey showed that 23% of patients have not been immunized with any vaccine, mainly due to lack of time, lack of medical prescription and high cost.

CONCLUSIONS

In this cohort, although vaccination rates are higher than previously reported, adherence to IBD immunization program would be improved, being considered since diagnosis by the multidisciplinary team.

Pregnancy in Inflammatory Bowel Disease: Experience of a Chilean cohort

BACKGROUND

In inflammatory bowel disease (IBD) a high percentage of women are diagnosed during their reproductive age. IBD in remission is the ideal scenario when planning a pregnancy.

AIMS

To describe the clinical characteristics of pregnancy/newborn and assess disease activity at the time of conception and throughout the pregnancy in patients with IBD treated at a tertiary centre in Chile.

METHODS

We retrospectively reviewed women diagnosed with IBD who were pregnant or delivered between 2017 and 2020. Demographic, clinical, obstetric and delivery data were obtained from the IBD registry, approved by the local IRB. Descriptive statistics and association tests were performed (χ2, p ≤ 0.05).

RESULTS

Sixty women with IBD were included. At the beginning of pregnancy, 21 (35%) had active disease and 39 (65%) were in remission. Of those with active disease, 16 (66%) remained active and 6 had spontaneous abortions. In those who were in remission, 26 (69%) remained in this condition. Nine patients (15%) discontinued treatment, and 6 of these had inflammatory activity during pregnancy. Preconception counselling was performed in 23 of the 60 patients, being higher in the group that remained in remission during pregnancy (65% vs. 35%, p = 0.02). Patients who had a flare during pregnancy had more probability of preterm birth (<37 weeks) and newborn with lower weight compared with the group that always remained in remission (89% vs. 74%, p = 0.161) and (2.885 vs 3.370 g; p = 0.0014).

CONCLUSION

Remission presents better outcomes in pregnancy and preconception counselling would allow a better IBD control during pregnancy.

Infliximab in inflammatory bowel disease. Is premedication necessary?

BACKGROUND

The use of infliximab (IFX) in inflammatory bowel disease (IBD) has been associated with a 1-6% risk of infusion reactions. The usefulness of premedication with corticosteroids, paracetamol and /or antihistamines is controversial.

AIM

The aim of this study is to assess, in IBD patients on IFX, whether there are differences in secondary reactions to the infusion between those who use premedication or not.

METHODS

A retrospective cohort study was performed identifying patients with a diagnosis of IBD who received IFX at our institution between January 2009 and July 2019. Acute reactions were defined as those that occurred in the first 24 hours postinfusion and late reactions for more than 24 hours. Infusion reactions were classified as mild, moderate and severe. Descriptive and association statistics were used (χ²; p < 0.05).

RESULTS

Sixty-four patients were included with 1,263 infusions in total, 52% men. Median infusions per patient was 22 (2-66). All induction infusions were administered with premedication, and in maintenance in 57% of them. Premedication was given with hydrocortisone, chlorphenamine and paracetamol. Most of reactions were acute, mild or moderate in severity and no patient needed to discontinue IFX. In the maintenance group, there were 9/718 (1.2%) infusion reactions with premedication and 4/358 (1.1%) without it (p = 0.606). In the induction group, there were 8/187 (4.3%) infusion reactions, significantly higher when compared with both maintenance groups.

CONCLUSIONS

In this group, premedication use during maintenance was not effective at reducing the rate of infusion reactions. These results suggest that premedication would not be necessary.

Characterization of Chilean patients with sporadic colorectal cancer according to the three main carcinogenic pathways: Microsatellite instability, CpG island methylator phenotype and Chromosomal instability

Molecular classification of colorectal cancer is difficult to implement in clinical settings where hundreds of genes are involved, and resources are limited. This study aims to characterize the molecular subtypes of patients with sporadic colorectal cancer based on the three main carcinogenic pathways microsatellite instability (MSI), CpG island methylator phenotype (CIMP), and chromosomal instability (CIN) in a Chilean population. Although several reports have characterized colorectal cancer, most do not represent Latin-American populations. Our study includes 103 colorectal cancer patients who underwent surgery, without neoadjuvant treatment, in a private hospital between 2008 and 2017. MSI, CIN, and CIMP status were assessed. Frequent mutations in KRAS, BRAF, and PIK3CA genes were analyzed by Sanger sequencing, and statistical analysis was performed by Fisher's exact and/or chi-square test. Survival curves were estimated with Kaplan-Meier and log-rank test. Based on our observations, we can classify the tumors in four subgroups, Group 1: MSI-high tumors (15%) are located in the right colon, occur at older age, and 60% show a BRAF mutation; Group 2: CIN-high tumors (38%) are in the left colon, and 26% have KRAS mutations. Group 3: [MSI/CIN/CIMP]-low/negative tumors (30%) are left-sided, and 39% have KRAS mutations; Group 4: CIMP-high tumors (15%) were more frequent in men and left side colon, with 27% KRAS and 7% presented BRAF mutations. Three percent of patients could not be classified. We found that CIMP-high was associated with a worse prognosis, both in MSI-high and MSI stable patients (p = 0.0452). Group 3 (Low/negative tumors) tend to have better overall survival compared with MSI-high, CIMP-high, and CIN-high tumors. This study contributes to understanding the heterogeneity of tumors in the Chilean population being one of the few characterizations performed in Latin-America. Given the limited resources of these countries, these results allow to improve molecular characterization in Latin-American colorectal cancer populations and confirm the possibility of using the three main carcinogenic pathways to define therapeutic strategies.

Progression of Inflammatory Bowel Diseases Throughout Latin America and the Caribbean: A Systematic Review

BACKGROUND & AIMS

The incidence of inflammatory bowel diseases (IBD) is increasing in Latin America. We performed a systematic review to identify clinical and epidemiologic features of IBD in Latin America (including Mexico, Central America, and South America) and the Caribbean.

METHODS

We searched MEDLINE, EMBASE, and SciELO databases for clinical or epidemiologic studies of Crohn's disease (CD) or ulcerative colitis (UC) from Latin American and Caribbean countries and territories that reported incidence, prevalence, ratio of UC:CD, IBD phenotype, and treatment, through September 12, 2018. Data were extracted from 61 articles for analysis.

RESULTS

The incidence and prevalence of IBD have been steadily increasing in Latin America and the Caribbean. The incidence of CD in Brazil increased from 0.08 per 100,000 person-years in 1988 to 0.68 per 100,000 person-years in 1991-1995 to 5.5 per 100,000 person-years in 2015. The highest reported prevalence of IBD was in Argentina, in 2007, at 15 and 82 per 100,000 person-years for CD and UC, respectively. The ratio of UC:CD exceeded 1 in all regions throughout Latin America and the Caribbean with the exception of Brazil. Treatment with tumor necrosis factor antagonists increased steadily for patients with CD (43.4% of all patients in Brazil were treated in 2014) but less so for patients with UC (4.5% of all patients were treated in 2014). Surgery for IBD decreased with time. In Chile, surgeries were performed on 57.0% of patients with CD and 18.0% of patients with UC during the period of 1990-2002; these values decreased to 38.0% and 5.0%, respectively, during the period of 2012-2015. In Peru, 6.9% of patients with UC received colectomies in the period of 2001-2003 and 6.2% in 2004-2014.

CONCLUSIONS

In a systematic review, we found the incidence of IBD to be increasing throughout Latin America and the Caribbean. Population-based epidemiology studies are needed to evaluate the increase in IBD in these regions, which differ from other global regions in climate, culture, demographics, diet, healthcare delivery and infrastructure, and socioeconomic status.

Inhibition of miR-378a-3p by Inflammation Enhances IL-33 Levels: A Novel Mechanism of Alarmin Modulation in Ulcerative Colitis

Ulcerative colitis (UC) is an inflammatory bowel disease (IBD) characterized by mucosa damage associated with an uncontrolled inflammatory response. This immunological impairment leads to altered inflammatory mediators such as IL-33, which is shown to increase in the mucosa of active UC (aUC) patients. MicroRNAs present a distorted feature in inflamed colonic mucosa and are potential IL-33 regulating candidates in UC. Therefore, we studied the microRNA and mRNA profiles in inflamed colonic samples of UC patients, evaluating the effect of a microRNA (selected by in silico analysis and its expression in UC patients), on IL-33 under inflammatory conditions. We found that inflamed mucosa (n = 8) showed increased expression of 40 microRNAs and 2,120 mRNAs, while 49 microRNAs and 1,734 mRNAs were decreased, as determined by microarrays. In particular, IL-33 mRNA showed a 3.8-fold increase and eight members of a microRNA family (miR-378), which targets IL-33 mRNA in the 3'UTR, were decreased (-3.9 to -3.0 times). We selected three members of the miR-378 family (miR-378a-3p, miR-422a, and miR-378c) according to background information and interaction energy analysis, for further correlation analyses with IL-33 expression through qPCR and ELISA, respectively. We determined that aUC (n = 24) showed high IL-33 levels, and decreased expression of miR-378a-3p and miR-422a compared to inactive UC (n = 10) and controls (n = 6). Moreover, both microRNAs were inversely correlated with IL-33 expression, while miR-378c does not show a significant difference. To evaluate the effect of TNFα on the studied microRNAs, aUC patients with anti-TNF therapy were compared to aUC receiving other treatments. The levels of miR-378a-3p and miR-378c were higher in aUC patients with anti-TNF. Based on these findings, we selected miR-378a-3p to exploring the molecular mechanism involved by in vitro assays, showing that over-expression of miR-378a-3p decreased the levels of an IL-33 target sequence β-gal-reporter gene in HEK293 cells. Stable miR-378a-3p over-expression/inhibition inversely modulated IL-33 content and altered viability of HT-29 cells. Additionally, in an inflammatory context, TNFα decreased miR-378a-3p levels in HT-29 cells enhancing IL-33 expression. Together, our results propose a regulatory mechanism of IL-33 expression exerted by miR-378a-3p in an inflammatory environment, contributing to the understanding of UC pathogenesis.

An approach to acute severe ulcerative colitis

Introduction: Despite the introduction of novel therapies and treatment strategies for ulcerative colitis (UC), many patients develop acute, severe episodes, warranting prompt care and aggressive management. There is a significant unmet need to improve outcomes in these patients. Clinicians must be able to identify those that will have worse prognosis and plan an aggressive therapy with an early/proactive adjustments in management if needed.Areas covered: The aim of this review is to evaluate the most recent evidence on the assessment and management of patients with acute severe ulcerative colitis. We searched the mainstream literature search engines for the most recent evidence on diagnosis and management of acute UC.Expert Opinion: The approach to patients with severe UC includes clinical and endoscopic assessment of disease severity and ruling out over-infections. While intravenous corticosteroids remain the first line therapy for acute severe colitis, many patients do not respond and require escalation to calcineurin inhibitors or infliximab, and may ultimately require colectomy. Even though several novel therapies are available or in development, their role in acute severe episodes of colitis is unknown.

Interleukin 33/ST2 Axis Components Are Associated to Desmoplasia, a Metastasis-Related Factor in Colorectal Cancer

In colorectal cancer (CRC), cancer-associated fibroblasts (CAFs) are the most abundant component from the tumor microenvironment (TM). CAFs facilitate tumor progression by inducing angiogenesis, immune suppression and invasion, thus altering the organization/composition of the extracellular matrix (i.e., desmoplasia) and/or activating epithelial-mesenchymal transition (EMT). Soluble factors from the TM can also contribute to cell invasion through secretion of cytokines and recently, IL-33/ST2 pathway has gained huge interest as a protumor alarmin, promoting progression to metastasis by inducing changes in TM. Hence, we analyzed IL-33 and ST2 content in tumor and healthy tissue lysates and plasma from CRC patients. Tissue localization and distribution of these molecules was evaluated by immunohistochemistry (using localization reference markers α-smooth muscle actin or α-SMA and E-cadherin), and clinical/histopathological information was obtained from CRC patients. In vitro experiments were conducted in primary cultures of CAFs and normal fibroblasts (NFs) isolated from tumor and healthy tissue taken from CRC patients. Additionally, migration and proliferation analysis were performed in HT29 and HCT116 cell lines. It was found that IL-33 content increases in left-sided CRC patients with lymphatic metastasis, with localization in tumor epithelia associated with abundant desmoplasia. Although ST2 content showed similarities between tumor and healthy tissue, a decreased immunoreactivity was observed in left-sided tumor stroma, associated to metastasis related factors (advanced stages, abundant desmoplasia, and presence of tumor budding). A principal component analysis (including stromal and epithelial IL-33/ST2 and α-SMA immunoreactivity with extent of desmoplasia) allowed us to distinguish clusters of low, intermediate and abundant desmoplasia, with potential to develop a diagnostic signature with benefits for further therapeutic targets. IL-33 transcript levels from CAFs directly correlated with CRC cell line migration induced by CAFs conditioned media, with rhIL-33 inducing a mesenchymal phenotype in HT29 cells. These results indicate a role of IL-33/ST2 in tumor microenvironment, specifically in the interaction between CAFs and epithelial tumor cells, thus contributing to invasion and metastasis in left-sided CRC, most likely by activating desmoplasia.

[Environmental risk factors in the development and evolution of inflammatory bowel disease]

Environmental factors may influence the development of Inflammatory Bowel Disease and modify its natural history. The objective of this review is to evaluate current evidence about environmental factors associated with the disease. A better knowledge about the pathogenesis of the disease can lead to better treatment strategies and suggestions to prevent the disease.

The relationship between chemokines CCL2, CCL3, and CCL4 with the tumor microenvironment and tumor-associated macrophage markers in colorectal cancer

A complex network of chemokines can influence cancer progression with the recruitment and activation of hematopoietic cells, including macrophages to the supporting tumor stroma promoting carcinogenesis and metastasis. The aim of this study was to investigate the relation between tissue and plasma chemokine levels involved in macrophage recruitment with tumor-associated macrophage profile markers and clinicopathological features such as tumor-node-metastases stage, desmoplasia, tumor necrosis factor-α, and vascular endothelial growth factor plasma content. Plasma and tumor/healthy mucosa were obtained from Chilean patients undergoing colon cancer surgery. Chemokines were evaluated from tissue lysates (CCL2, CCL3, CCL4, CCL5, and CX3CL1) by Luminex. Statistical analysis was performed using Wilcoxon match-paired test ( p  < 0.05). Macrophage markers (CD68, CD163, and iNOS) were evaluated by immunohistochemistry samples derived from colorectal cancer patients. Correlation analysis between chemokines and macrophage markers and clinicopathological features were performed using Spearman's test. Plasmatic levels of chemokines and inflammatory mediators' vascular endothelial growth factor and tumor necrosis factor-α were evaluated by Luminex. Tumor levels of CCL2 (mean ± standard deviation = 530.1 ± 613.9 pg/mg), CCL3 (102.7 ± 106.0 pg/mg), and CCL4 (64.98 ± 48.09 pg/mg) were higher than those found in healthy tissue (182.1 ± 116.5, 26.79 ± 22.40, and 27.06 ± 23.69 pg/mg, respectively p < 0.05). The tumor characterization allowed us to identify a positive correlation between CCL4 and the pro-tumor macrophages marker CD163 ( p  = 0.0443), and a negative correlation of iNOS with desmoplastic reaction ( p  = 0.0467). Moreover, we identified that tumors with immature desmoplasia have a higher CD163 density compared to those with a mature/intermediated stromal tissue ( p  = 0.0288). Plasmatic CCL4 has shown a positive correlation with inflammatory mediators (tumor necrosis factor-α and vascular endothelial growth factor) that have previously been associated with poor prognosis in patients. In conclusion High expression of CCL4 in colon cancer could induce the infiltration of tumor-associated macrophages and specifically a pro-tumor macrophage profile (CD163⁺ cells). Moreover, plasmatic chemokines could be considered inflammatory mediators associated to CRC progression as well as tumor necrosis factor-α and vascular endothelial growth factor. These data reinforce the idea of chemokines as potential therapeutic targets or biomarker in CRC.

Complementary and alternative medicine in patients with inflammatory bowel disease: A survey performed in a tertiary center in Chile

OBJECTIVES

The aim of this study was to assess the type and prevalence of complementary and alternative medicine (CAM) use in patients with inflammatory bowel disease (IBD) who are treated at our center.

DESIGN

Observational, cross-sectional questionnaire-based study that included patients from the IBD program of our center.

SETTING

Tertiary clinical center in Santiago, Chile.

MAIN OUTCOME MEASURES

Types of CAM being used by patients with IBD.

RESULTS

A total of 200 patients were included, 68% ulcerative colitis, 29% Crohn's disease, and 3% non-classifiable IBD. Overall, 25% of the patients reported current use of CAM, 30% reported using in it the past, and 45% indicated that they had never used it before. The use of CAM was recommended in 20% of the patients by other healthcare professionals and in 10% of the patients by the gastroenterologist. Forty-nine percent of the patients informed the gastroenterologist that they were using CAM. Overall, 86% of the patients did not modify the conventional medical treatment (CMT). None of the patients who were using curcumin, homeopathic medicine, acupuncture or biomagnetism modified the CMT.

CONCLUSIONS

The type of CAM being used plays an important role when the patient makes the decision to inform the gastroenterologist. Other healthcare professionals play an important role in providing the advice to start CAM. Gastroenterologists must be aware of the high prevalence of CAM use in IBD patients, actively ask about CAM use and guide the patients who want to use CAM in a responsible and safe manner.

[Presence of intracellular Escherichia coli in patients with inflammatory bowel disease]

BACKGROUND

Different strains of invasive Escherichia coli (E. coli), isolated from intestinal mucosa of patients, are related to the pathogenesis of inflammatory bowel diseases (IBD).

AIM

To evaluate an association between intracellular E. coli and IBD; its clinical characteristics and use of steroids.

MATERIAL AND METHODS

Sixty one patients with Crohn's disease and 83 with ulcerative colitis were studied. To determine the intracellular E. coli content, colonoscopy biopsies of these patients and 29 control subjects were processed using the gentamicin protection assay. Differences in the bacterial content between patient groups were evaluated using Mann-Whitney test, while the association between presence of E. coli with endoscopic activity, location/extension and use of corticosteroid as anti-inflammatory treatment were evaluated with Fisher's exact test or Chi-square test.

RESULTS

E. coli strains were detected in 36.1, 39.3 and 10.3% of patients with ulcerative colitis, Crohn's disease and controls, respectively. The number of bacteria per biopsy in Crohn's disease and ulcerative colitis was significantly higher than in controls (p < 0.01 between patients and controls). In ulcerative colitis, significant associations were found between the presence of bacteria and disease location and use of corticosteroids. In Crohn's disease, no association was found.

CONCLUSIONS

IBD are associated with the presence of intracellular E. coli strains in the intestinal mucosa, suggesting an alteration in the microbiota or loss of integrity of the epithelial barrier. The association of intracellular E. coli with clinical features and the use of corticosteroids in ulcerative colitis suggests that different factors could promote colonization or proliferation of these bacteria.

[Rectal diffuse large B cell lymphoma appearing after immunosuppression for ulcerative colitis. Report of one case]

Primary colorectal lymphoma is a rare form of presentation of gastrointestinal tract lymphomas. Inflammatory bowel disease and its treatment are risk factors for its development. We report a 47-year-old male patient with Ulcerative Colitis of two years of evolution, treated initially with azathioprine and later on with infliximab. Due to a relapse in symptoms after the second dose of infliximab, a new coloncoscopy was performed showing a rectal ulcerative lesion, corresponding to a large cell Non-Hodgkin's Lymphoma. The patient was successfully treated with RCHOP chemotherapy (Rituximab cyclophosphamide doxorubicin vincristine prednisone). He is currently in disease remission.

[Acute severe ulcerative colitis treated with accelerated infliximab induction. Case report]

Acute severe ulcerative colitis (ASUC) is a potentially life-threatening condition that requires early recognition, hospitalization and adequate treatment. Currently, the use of infliximab in ulcerative colitis (UC) is recommended in the case of severe disease refractory to corticosteroids, once that superimposed bacterial or viral infections (such as cytomegalovirus or Clostridium difficile) have been excluded. However, conventional weight-based regimens of infliximab might be insufficient for patients with ASUC. Accelerated infliximab induction regimen may increase its serum concentration levels and efficacy by reducing early colectomy rates in these patients. We report a 34 year old female presenting with an ASUC. She was initially treated with hydrocortisone 300 mg/day and mesalazine enemas 4 g/day with an unfavorable clinical response. At the fifth day of therapy, an accelerated induction therapy with infliximab was started in doses of 10 mg/kg at weeks 0, 1 and 4. After the second dose, there was a favorable response with reduction of abdominal pain, stool frequency and hematochezia. She was discharged with prednisone and azathioprine. After a year of starting infliximab, the patient remains in clinical remission.

Clinical, endoscopic and histological correlation and measures of association in ulcerative colitis

OBJECTIVE

To determine the correlation between clinical, fecal, endoscopic and histological activity in patients with ulcerative colitis (UC).

METHODS

A correlational cross-sectional analysis was performed in patients with UC who underwent colonoscopy between February and December 2016. Clinical, endoscopic, fecal and histological activities were determined using the partial Mayo subscore, Mayo endoscopic subscore and modified Mayo endoscopic subscore, fecal calprotectin and Geboes score and the presence of basal plasmacytosis, respectively. Scores were analyzed using Spearman's rank correlation test. To determine the association between scores and some clinical variables and active UC, univariate and multivariate logistic regressions were used.

RESULTS

Altogether 105 procedures (93 patients) were included. In 64.8% of the procedures, the mucosa was inflamed; however, 14.7% did not show histological inflammation. Endoscopic remission was observed in the other 35.2% of procedures; however, in biopsies 21.6% exhibited histological inflammation. Mayo endoscopic subscore and modified Mayo endoscopic score were well correlated but were only moderately correlated with clinical and histological scores. Furthermore, there was a moderate correlation between Mayo endoscopic score and Geboes score. Conversely, histological scores were poorly correlated with partial Mayo score. In multivariate analysis, Geboes score and basal plasmacytosis were predictive of active disease (OR 3.505, 95% CI 1.544-7.959 and OR 3.240, 95% CI 1.123-9.349, respectively), whereas biological therapy was found to be protective against UC (OR 0.021, 95% CI 0.000-0.641).

CONCLUSION

Clinical, endoscopic and histological activities were moderately correlated, while Geboes score and basal plasmacytosis were predictive of endoscopically active UC.

Corrigendum: Helicobacter pylori cagA+ Is Associated with Milder Duodenal Histological Changes in Chilean Celiac Patients

[This corrects the article on p. 376 in vol. 7, PMID: 28879170.].

[Characterization of patients with sporadic colorectal cancer following the new Consensus Molecular Subtypes (CMS)]

BACKGROUND

Colorectal cancer (CRC) is an heterogeneous disease. Three carcinogenic pathways determine its molecular profile: microsatellite instability (MSI), chromosomal instability (CIN) and CpG island methylator phenotype (CIMP). Based on the new molecular classification, four consensus CRC molecular subtypes (CMS) are established, which are related to clinical, pathological and biological characteristics of the tumor.

AIM

To classify Chilean patients with sporadic CRC according to the new consensus molecular subtypes of carcinogenic pathways.

MATERIAL AND METHODS

Prospective analytical study of 53 patients with a mean age of 70 years (55% males) with CRC, operated at a private clinic, without neoadjuvant treatment. From normal and tumor tissue DNA of each patient, CIN, MSI and CIMP were analyzed. Combining these variables, tumors were classified as CMS1/MSI-immune, CMS2/canonical, CMS3/metabolic and CMS4/mesenchymal.

RESULTS

CMS1 tumors (19%) were located in the right colon, were in early stages, had MMR complex deficiencies and 67% had an activating mutation of the BRAF oncogene. CMS2 tumors (31%) were located in the left colon, had moderate differentiation, absence of vascular invasion, lymphatic and mucin. CMS3 tumors (29%) were also left-sided, with absence of vascular and lymphatic invasion, and 29% had an activating mutation of the KRAS oncogene. CMS4 tumors (21%) showed advanced stages and presence of metastases.

CONCLUSIONS

This new molecular classification contributes to understanding the heterogeneity of tumors. It is possible to differentiate molecular subgroups of a single pathological diagnosis of adenocarcinoma, opening the door to personalized medicine.

Helicobacter pylori cagA+ Is Associated with Milder Duodenal Histological Changes in Chilean Celiac Patients

HIGHLIGHTS

What is already known about this subject?

Celiac disease (CD) has a high clinical and histological diversity and the mechanisms underlying this phenomenon remain elusive.

H. pylori is a bacterium that chronically infect gastric and duodenal mucosa activating both a Th1/Th17 and T-reg pathways.

The role of H. pylori (and the effect of their virulence factors) in CD have not yet completely elucidated.

What are the new findings?

cagA+ H. pylori strains are associated to milder histological damage in infected CD patients.

In active-CD patients the presence of cagA+ H. pylori is associated to an increase in T-reg markers, contrasting with a downregulation in cagA+ infected potential-CD individuals.

How might it impact on clinical practice in the foreseeable future?

The identification of microbiological factors that could modulate inflammation and clinical expression of CD may be used in the future as preventive strategies or as supplementary treatment in patients that cannot achieve complete remission, contributing to the better care of these patients.

Background: Mechanisms underlying the high clinical and histological diversity of celiac disease (CD) remain elusive. Helicobacter pylori (Hp) chronically infects gastric and duodenal mucosa and has been associated with protection against some immune-mediated conditions, but its role (specifically of cagA+ strains) in CD is unclear.

Objective: To assess the relationship between gastric Hp infection (cagA+ strains) and duodenal histological damage in patients with CD.

Design: Case-control study including patients with active-CD, potential-CD and non-celiac individuals. Clinical presentation, HLA genotype, Hp/cagA gene detection in gastric mucosa, duodenal histology, Foxp3 positive cells and TGF-β expression in duodenal lamina propria were analyzed.

Results: We recruited 116 patients, 29 active-CD, 37 potential-CD, and 50 non-CD controls. Hp detection was similar in the three groups (~30–40%), but cagA+ strains were more common in infected potential-CD than in active-CD (10/11 vs. 4/10; p = 0.020) and non-CD (10/20; p = 0.025). Among active-CD patients, Foxp3 positivity was significantly higher in subjects with cagA+ Hp+ compared to cagA- Hp+ (p < 0.01) and Hp- (p < 0.01). In cagA+ Hp+ individuals, Foxp3 positivity was also higher comparing active- to potential-CD (p < 0.01). TGF-β expression in duodenum was similar in active-CD with cagA+ Hp+ compared to Hp- and was significantly downregulated in cagA+ potential-CD subjects compared to other groups.

Conclusion: Hp infection rates were similar among individuals with/without CD, but infection with cagA+ strains was associated with milder histological damage in celiac patients infected by Hp, and in active-CD cases with higher expression of T-reg markers. Results suggest that infection by cagA+ Hp may be protective for CD progression, or conversely, that these strains are prone to colonize intestinal mucosa with less severe damage.

Abstract 3943: Determination of the molecular profile of Chilean patients with sporadic colorectal cancer

Introduction: Colorectal cancer (CRC) represents a major health problem worldwide, ranking third among the most frequent cancers and fourth in cancer mortality. In Chile CRC is the third leading cause of cancer death. CRC is a heterogeneous disease, and three carcinogenic pathways have been described to determine the molecular profile: The microsatellite instability (MSI), chromosomal instability (CIN) and methylator phenotype (CIMP). Several studies have tried to propose CRC molecular subgroups based on the 3ways described above since CIN, MSI and CIMP are not mutually exclusive and overlapping of the 3 ways is still unclear. The most recent subtyping of CRC was in 2015, where four molecular subtypes consensus (CMS 1 to 4) were established according to clinicopathological features, molecular pathways involved and mutational status of KRAS, BRAF and PI3KCA genes in order to encourage clinical translation. 21% of tumors failed to be categorized into these subtypes. This classification allows us to understand and determine the clinical, pathological and biological characteristics of CCR to provide customized therapies to patients.

Aim: To describe the molecular profile of carcinogenic pathways CIN, MSI CIMP in Chilean patients with sporadic CRC.

Material and Methods: Prospective analytical study of 56 patients operated between 2010-2016 at Clinica Las Condes, without neo-adjuvant treatment. DNA was extracted from normal and tumor tissue of each patient and using PCR amplification of several markers CIN, MSI and CIMP were defined. By combining the 3 variables analyzed, tumors were classified in Group-A (MSI-high), Group-B (MSI-low / CIMP-high / CIN-high), Group-C (MSI-low / CIMP-high / CIN-low), Group-D (MSI-low / CIMP-low / CIN-high) and Group-E (MSI- neg / CIMP-neg / CIN-neg).

Results: In this study, tumors in Group-A (17%) are located on the right side in patients older than 60 years and early stages. Tumors Group-B / C (18,9%) occur in patients older than 60 years and BMI&gt;25 kg / m2, with wall invasion pT3-T4 and late stages. Tumors of Group-D / E (54,7%) are the most frequent, located on the left side, without vascular invasion and moderately differentiated.

Conclusions: This study allowed to classify Chilean patients in 3 subgroups considering the 3 main routes described for carcinogenesis development: CIN, MSI and CIMP, which are consistent with the percentages described by the global consortium. Studies that analyze MSI and CIMP or MSI and CIN have consistently shown that patients with MSI-high tumors have a better prognosis (in our case 17%). Despite therapeutic advances based on this molecular characterization, both the heterogeneity of tumors and the different combinations of pathways involved have shown that the response to therapy varies depending on the individual profile of each patient, therefore in clinical practice it would be important to establish that profile for each of them. Fondecyt 1140012

Citation Format: Ana Maria Wielandt, Cynthia Villarroel, Claudia Hurtado, Daniela Simian, Diego Zamorano, Maripaz Martinez, Magdalena Castro, Maria Teresa Vial, Udo Kronberg, Francisco Lopez-Kostner. Determination of the molecular profile of Chilean patients with sporadic colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3943. doi:10.1158/1538-7445.AM2017-3943

Assessment of disease-related knowledge and possible factors associated with the knowledge level among Chilean patients with inflammatory bowel disease

AIMS AND OBJECTIVES

To assess disease-related knowledge among patients with inflammatory bowel disease and to identify the factors that are possibly associated with the knowledge level.

BACKGROUND

Disease-related knowledge can positively influence the acceptance of the disease, increase treatment compliance and improve the quality of life in patients with inflammatory bowel disease.

DESIGN

An observational, cross-sectional study was conducted and prospectively included patients from the inflammatory bowel disease programme between October 2014-July 2015.

METHODS

A Spanish-translated version of the 24-item Crohn's and Colitis Knowledge score was used to assess disease-related knowledge. Patients also completed a demographic and clinical questionnaire.

RESULTS

A total of 203 patients were included, 62% were female, and 66% were diagnosed with ulcerative colitis; the median age was 34 years (range 18-79), and the median disease duration was four years. The median disease-related knowledge score was 9 (range 1-20). Only 29% of the patients answered more than 50% of the questions correctly. Lower disease-related knowledge was observed in questions related to pregnancy/fertility and surgery/complications. Patients older than 50 years, with ulcerative colitis, with disease durations less than five years and patients without histories of surgery exhibited lower disease-related knowledge. There was no association between the knowledge scores and the educational levels.

CONCLUSIONS

The patients who attended our inflammatory bowel disease programme exhibited poor disease-related knowledge that was similar to the knowledge levels that have been observed in developed countries. It is necessary to assess patient knowledge to develop educational strategies and evaluate the influences of these strategies on patient compliance and quality of life.

RELEVANCE TO CLINICAL PRACTICE

These results will allow the inflammatory bowel disease team to develop educational programmes that account for the disease-related knowledge of each patient. Inflammatory bowel disease nurses should evaluate their interventions to provide evidence that educating our patients contributes to improving their treatment outcomes and overall health statuses.

[Towards an integral management of inflammatory bowel disease]

Inflammatory Bowel Disease (IBD) is a chronic inflammatory condition of the gastrointestinal tract with medical and psychological complications. Addressing psychosocial aspects of treatment, such as quality of care and disability remains a challenge. The quality of care for IBD patients is not optimal at the present time and there is a variation in the care provided by specialists. Therefore, it is necessary to develop well defined quality indicators to assure the delivery of an adequate care to these patients. The delivery of healthcare for IBD patients is often complex and requires multidisciplinary teams. The ultimate objectives in the treatment of IBD should be to prevent bowel damage, reduce long-term disability and maintain a normal quality of life.

Soluble ST2 is a sensitive clinical marker of ulcerative colitis evolution

BACKGROUND

The ST2/IL-33 pathway has been related to ulcerative colitis (UC), and soluble ST2 (sST2), to disease severity. We tested the potential usefulness of sST2 as a predictive marker of treatment response and patients' outcome.

METHODS

Twenty-six patients with active UC were prospectively recruited and grouped according to an endoscopic score and therapy response. Colonoscopic biopsies were collected at baseline and 6 months or when patients showed clinical activity. The protocol was reinitiated in patients requiring rescue therapy. Blood and stool were collected at baseline, 1, 3, 6 and 12 months. Serum and mucosal ST2, and fecal calprotectin (FC) content were determined by ELISA and correlated to Mayo clinical and endoscopic subscore. Intestinal ST2 was evaluated by immunofluorescence. Wilcoxon signed rank test and Spearman correlations (Rs) were applied (p <0.05).

RESULTS

Follow-up was completed in 24 patients. sST2 levels (median and range) varied from 173.5 [136.6-274.0] to 86.5 [54.6-133.2] in responders (p < 0.05), and 336.3 [211.0-403.2] to 385.3 pg/mL [283.4-517.3] in non-responders at baseline and 6 months, respectively. sST2 levels correlated with Mayo clinical and endoscopic subscore, mucosal ST2 and FC (Rs = 0.57, 0.66, 0.74 and 0.42, respectively; p < 0.0001) and showed a trend similar to that of FC in responders. Non-responders revealed an increased ST2 content, restricted to the lamina propria's cellular infiltrate.

CONCLUSIONS

Consecutive sST2 measurement to follow changes in inflammatory activity of UC patients who respond or not to treatment identifies sST2, like FC, as a useful biomarker in predicting clinical outcome of UC patients.

Abstract 5167: Expression levels of orexin receptor 1 in different stages of colorectal cancer

Introduction: Colorectal cancer (CRC) is the fourth leading cause of cancer death in Chile. Currently, treatment is surgical and adjuvance is based on chemotherapy mainly. One of the risk factors of CRC is obesity and metabolic syndrome. In search of factors that induce cell apoptosis, orexins were identified. Orexins are neuropeptides that regulate appetite, inhibit satiety and increase energy expenditure. The altered expression of orexin or its dysregulation has been associated with a wide range of human diseases such as narcolepsy, obesity, drug addiction and cancer. In rats and mice lacking orexin receptor, an increase in body mass index (BMI) was observed. Orexin Receptor 1 (OX1R) is overexpressed in CRC, but is not detected in normal colon tissue. Its activation by Orexin-A promotes apoptosis in cancer cell lines, and can be modulated by diet. Aim: To determine OX1R expression in the adenoma-carcinoma progression of CRC as possible therapeutic target, and its correlation with BMI. Material and Methods: Patients with neoplastic colorectal lesions undergoing surgical or endoscopic treatment between 2014 and 2015 were prospectively enrolled. Tissue samples of 29 patients were divided into 4 groups. Group A: control (n = 5), Group B: low-grade adenoma (n = 5), Group C: high-grade adenoma (n = 7), Group D: adenocarcinoma (n = 12). Formalin-fixed-paraffin-embedded samples were used to perform immunohistochemistry (IHC) of OX1R. Fresh tissues from Group D were used to assess protein and mRNA expression of OX1R by Western-blot and quantitative RT-PCR, respectively. Primary cultures were established from fresh tumor tissue of patients with adenocarcinoma. To compare OX1R expression levels we used the t-student test. Results: IHC expression of OX1R was detected both in the luminal membrane of colorectal epithelium and in the cytoplasm. We observed stained cells in 0-1% of the total area in Group A, B and C. In Group D, 7 samples showed staining 0-1%, 2 samples 1-10% and 3 samples 10-20%. High mRNA and protein expression was detected in stage III- IV adenocarcinoma samples compared to stage 0, I and II tumor samples. Normal adyacent tissue of CRC patients does not express OX1R. BMI is inversely associated with OX1R expression. Orexin A was able to induce apoptosis in primary cell cultures from advanced tumors in a dose dependent manner. Conclusions: OX1R is expressed scarcely in early stages of carcinogenesis. Its expression is induced significantly only in the most advanced adenocarcinomas, both at protein and mRNA levels, and is inversely associated with BMI. In primary cultures of patients with CRC, orexin A is able to induce apoptosis in a dose dependent manner. FONDECYT 1140012.

Citation Format: Ana M. Wielandt, Cynthia Villarroel, Claudia Hurtado, Kento Inada, Hiroshi Kawachi, Daniela Simian, Maria T. Vial, Marcela Figueroa, Magdalena Castro, Udo Kronberg, Francisco Lopez-Kostner. Expression levels of orexin receptor 1 in different stages of colorectal cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 5167.

Inflammatory bowel disease: A descriptive study of 716 local Chilean patients

AIM: To demographically and clinically characterize inflammatory bowel disease (IBD) from the local registry and update data previously published by our group.

METHODS: A descriptive study of a cohort based on a registry of patients aged 15 years or older who were diagnosed with IBD and attended the IBD program at Clínica Las Condes in Santiago, Chile. The registry was created in April 2012 and includes patients registered up to October 2015. The information was anonymously downloaded in a monthly report, and the information on patients with more than one visit was updated. The registry includes demographic, clinical and disease characteristics, including the Montreal Classification, medical treatment, surgeries and hospitalizations for crisis. Data regarding infection with Clostridium difficile (C. difficile) were incorporated in the registry in 2014. Data for patients who received consultations as second opinions and continued treatment at this institution were also analyzed.

RESULTS: The study included 716 patients with IBD: 508 patients (71%) were diagnosed with ulcerative colitis (UC), 196 patients (27%) were diagnosed with Crohn’s disease (CD) and 12 patients (2%) were diagnosed with unclassifiable IBD. The UC/CD ratio was 2.6/1. The median age was 36 years (range 16-88), and 58% of the patients were female, with a median age at diagnosis of 29 years (range 5-76). In the past 15 years, a sustained increase in the number of patients diagnosed with IBD was observed, where 87% of the patients were diagnosed between the years 2001 and 2015. In the cohort examined in the present study, extensive colitis (50%) and colonic involvement (44%) predominated in the patients with UC and CD, respectively. In CD patients, non-stricturing/non-penetrating behavior was more frequent (80%), and perianal disease was observed in 28% of the patients. There were significant differences in treatment between UC and CD, with a higher use of corticosteroids, and immunosuppressive and biological therapies was observed in the patients with CD (P < 0.05 and P < 0.01). Significant surgical differences were also observed: 5% of the UC patients underwent surgery, whereas 38% of the CD patients required at least one surgery (P < 0.01). The patients with CD were hospitalized more often during their disease course than the patients with UC (55% and 35% of the patients, respectively; P < 0.01). C. difficile infection was acquired by 5% of the patients in each group at some point during the disease course. Nearly half of the patients consulted at the institution for a second opinion, and 32% of these individuals continued treatment at the institution.

CONCLUSION: IBD has continued to increase in the study cohort, slowly approaching the level reported in developed countries.

[Differences by age in clinical features of inflammatory bowel disease]

BACKGROUND

Approximately, 15% of patients with Inflammatory Bowel Disease (IBD) are diagnosed at 60 years of age or more.

AIM

To characterize and compare clinical variables between patients with IBD aged 60 years or more and their younger counterparts.

MATERIAL AND METHODS

Retrospective study based on a registry of IBD patients diagnosed between the years 1976 and 2014.

RESULTS

Four hundred and nine IBD patients were included. Among them, 294 had Ulcerative Colitis (UC), 104 had Crohn's Disease (CD) and eleven had an indeterminate IBD. Forty-six patients (11.2%) were older than 60 years and 16 (3.9%) had been diagnosed after this age. When comparing patients by age, those aged 60 years or more had a higher frequency of CD and indeterminate IBD (p < 0.01) and a lower ileocolic location in CD (p = 0.02). Both groups were similar in terms of hospitalization due to IBD flare, surgery, use of steroids, immunosuppressive or biological therapies and drug-related adverse events. When analyzing age at diagnosis of IBD, patients diagnosed at ages of 60 years or more had a lower frequency of UC (p < 0.01), a higher frequency of exclusive colonic involvement (p = 0.01), and lower use of mesalamine (p < 0.01). There were no differences in drug-related adverse events, hospitalizations due to IBD flares and surgery according to age at diagnosis.

CONCLUSIONS

In this population, clinical features of IBD in older patients were similar to those in younger patients.

[Inflammatory bowel disease. Experience in 316 patients]

BACKGROUND

The incidence and prevalence of Inflammatory Bowel Disease (IBD) has increased.

AIM

To determine demographic and clinical characteristics of patients with IBD in a Chilean private hospital.

PATIENTS AND METHODS

Review of a prospective registry of patients with IBD, started on 2012. It includes clinical, imaging, endoscopical and pathological information of patients.

RESULTS

Data of 316 patients with IBD, aged 16 to 86 years (56% females), were analyzed. Ulcerative Colitis (UC), Crohn´s and non-classifiable IBD were diagnosed in 230, 77 and 9 patients, respectively. The disease was diagnosed in 82% of patients in the period between 2002 and 2012. There was a peak in the diagnosis of both UC and CD between 20 and 39 years of age, without gender differences. The disease switched from UC to CD in six patients. In four, there was a change in disease behavior. Thirty eight patients were treated with biological therapy. The median lapse between the diagnosis and the use of biological therapy was 1 year in patients diagnosed after 2007, compared with 5.5 years among those patients diagnosed before 2007 (p = 0.001). There was a trend towards a higher requirement of surgery until 2006. Subsequently there was a stabilization of the requirement, concomitant with the incorporation of biological therapy.

CONCLUSIONS

An adequate registry of IBD patients is necessary to improve demographic and clinical characteristics. A national registry is needed to assess the epidemiological changes of IBD in Chile.

[Development of malignant tumors in patients with inflammatory bowel disease]

BACKGROUND

The chronic inflammation of the intestinal mucosa, the extra-intestinal manifestations of the disease and the immunosuppressive treatment of inflammatory bowel disease may increase cancer risk.

AIM

To report the demographic and clinical features of patients with IBD who developed a malignant tumor.

MATERIAL AND METHODS

Retrospective analysis of an IBD patient registry of a private clinic, diagnosed between 1976 and 2014.

RESULTS

437 subjects were included, aged 15-88 years (58% women). Seventy two percent of patients had ulcerative colitis. The median time of follow up was 6 years. Ten patients (2.3%) developed a malignant tumor. In four, the tumor could be related to IBD (two colorectal cancers, one cholangiocarcinoma and one chronic myeloid leukemia (CML)). Two of 45 patients treated with biological therapy developed a tumor (CML and hypernephroma). Three of 170 patients on immunosuppressive treatment developed tumors. Only one had a tumor possibly related with the use of azathioprine (non-melanoma skin cancer). In only two patients, the treatment was changed at the time of their cancer diagnosis, from immunosuppressive medications to mesalamine.

CONCLUSIONS

Only a small proportion of these patients with IBD developed a malignant tumor. The treatment of IBD has to be determined by the severity of the disease and not by the fear of developing a neoplasia. Following recommendations is fundamental to decrease the possibility of developing this complication.

[Fecal microbiota transplantation in recurrent Clostridium difficile infection. Report of one case]

Fecal microbiota transplantation (FMT) has an incomparable efficacy to treat recurrent Clostridium difficile infection, with near 90% of success. We report a 57 years old woman who developed an antibiotic associated diarrhea with a positive polymerase chain reaction test for Clostridium Difficile toxin. She was successfully treated with Vancomycin trice but diarrhea recurred. Therefore a fecal microbiota transplant was performed using solid stools from a relative, diluted in saline and instilled in the distal ileon, with a good clinical response, without recurrence of diarrhea, during a 6-month follow-up.