Bacterial microbiome changes after fecal transplantation for recurrent Clostridioides difficile infection in the Brazilian center.

Clostridioides difficile infection (CDI) poses a significant global health threat owing to its substantial morbidity and associated healthcare costs. A key challenge in controlling CDI is the risk of multiple recurrences, which can affect up to 30% of patients. In such instances, fecal microbiota transplantation (FMT) is increasingly recognized as the optimal treatment. However, few related studies have been conducted in developing countries, and the microbiota composition of Brazilian patients and its dynamic modification post-FMT remain largely unexplored. This study aimed to evaluate the changes in the bacterial gut microbiome in Brazilian patients with recurrent CDI post-FMT. Ten patients underwent FMT, and the primary and overall CDI resolution rates were 80% and 90% after the first and second FMT, respectively. FMT was associated with an early increase in Shannon's diversity, evident as soon as 1 week post-FMT and persisting for at least 25 days post-treatment. Post-treatment, the abundance of Firmicutes increased and that of Proteobacteria decreased. Specifically, the abundance of the genera Ruminococcus, Faecalibacterium, Lachnospira, and Roseburia of the Firmicutes phylum was significantly higher 1 week post-transplantation, with Ruminococcus and Faecalibacterium remaining enriched 25 days post-transplantation. This study is the first of its kind in Brazil to evaluate the microbiota of a donor and patients undergoing FMT. Our findings suggest that FMT can induce remarkable changes in the gut microbiota, characterized by an early and sustained increase in diversity lasting at least 25 days. FMT also promotes enrichment of genera such as Ruminococcus spp., Faecalibacterium spp., and Roseburia spp., essential for therapeutic success.

Helicobacter pylori and colorectal neoplasms: a concise review.

Helicobacter pylori is the main etiological agent of all malignant tumors caused by an infectious disease. It is a major, at times dominant, factor in the pathogenesis of a large spectrum of diseases such as acute and chronic gastritis, gastric and duodenal ulcers, gastric carcinoma, and lymphoma. Epidemiological and experimental studies suggest that H. pylori chronic infection may be related to different extragastric diseases, including colorectal neoplasms. This concise review aims to explore the association of H. pylori infection with colorectal cancer and adenoma, including the recent epidemiological findings, the diagnostic methods employed to detect H. pylori and virulent factors, and the potentially involved mechanisms. Furthermore, is attempted to establish the current data integration for causal inference using the Bradford-Hill causality criteria. The weak, although global, strength of the epidemiological positive association between H. pylori infection and colonic neoplasms associated to new mechanisms postulated to explain this interaction, including intestinal dysbiosis, should stimulate future studies. Prospective confirmatory studies to establish the role of H. pylori eradication in the process of carcinogenic transformation of the colonic epithelium may define its eventual role in the treatment and prevention of colonic neoplasms.

HELICOBACTER PYLORI CHRONIC GASTRITIS ON PATIENTS WITH PREMALIGNANT CONDITIONS: OLGA AND OLGIM EVALUATION AND SERUM BIOMARKERS PERFORMANCE.

BACKGROUND: H. pylori chronic atrophic gastritis is a premalignant lesion, and its staging, according to OLGA and OLGIM systems aims to identify patients at increased risk of developing gastric cancer and optimize their follow-up. GastroPanel®, serum biomarkers panel including pepsinogen I (PGI), pepsinogen II (PGII), Gastrin 17 (G17) and anti- H. pylori antibodies is a noninvasive test for adenocarcinoma risk assessment in chronic H. pylori gastritis patients. OBJECTIVE: Prospective study to evaluate the concordance between OLGA and OLGIM grading systems, as well as to evaluate GastroPanel´s performance in patients with premalignant lesions secondary to H. pylori chronic gastritis in Brazil. METHODS: Patients with H. pylori chronic gastritis with premalignant lesions confirmed by histology were recruited from the gastrointestinal clinic of a University Hospital. All participants underwent endoscopic examination with biopsies which were reported according to updated Sydney system and premalignant lesions grading systems (OLGA and OLGIM). Blood samples were collected for biomarkers serological analysis (GastroPanel®, Biohit, Helsinki, Finland). The cut off values used to define high risk patients were those recommended by the manufacturer: PGI ≤30 µm/L and PGI/PGII ≤3. RESULTS: 41 patients were recruited: 28 women, 13 men, mean age 67.3 (47-89, SD: 9.6) years. By OLGA system, were obtained: OLGA 0 (n=1), OLGA I (n=7), OLGA II (n=17), OLGA III (n=9), and OLGA IV (n=7). By OLGIM system, were obtained: OLGIM 0 (n=14), OLGIM I (n=5), OLGIM II (n=10), OLGIM III (n=10), and OLGIM IV (n=2). Regarding histological staging among patients staged as low risk (OLGA/OLGIM 0, I and II) and high risk (OLGA/OLGIM III and IV) for gastric cancer development, the concordance rate found between both classifications was 85.4%. Considering high risk patients, those patients thus included in at least one of the systems the final distribution of our sample considered 24 low-risk and 17 high-risk patients for the development of gastric cancer. To determine by GastroPanel® whether the patient would be at low or high risk of developing gastric cancer, PGI showed a sensitivity, specificity and accuracy of 0.47 (95%CI: 0.26-0.69), 0.67 (95%CI: 0.47-0.82), and 0.58 (95%CI: 0.43-0.72), respectively, while PGI/PGII showed sensitivity, specificity and accuracy of 0.06 (95%CI: 0.01-0.27), 0.83 (95%CI: 0.64-0.93) and 0.51 (95%CI: 0.36-0.66), respectively. CONCLUSION: The histological classifications OLGA and OLGIM presented a substantial concordance rate among themselves. Simultaneous use of both histological classification systems increased the identification's rate of high-risk patients. Biomarker analysis was not effective to distinguish low to high risk patients in the studied population. Further studies are needed to validate its use in clinical practice in Brazil.

Helicobacter pylori and colorectal neoplasms: a concise review / Helicobacter pylori e neoplasias colorretais: revisão concisa

ABSTRACT Helicobacter pylori is the main etiological agent of all malignant tumors caused by an infectious disease. It is a major, at times dominant, factor in the pathogenesis of a large spectrum of diseases such as acute and chronic gastritis, gastric and duodenal ulcers, gastric carcinoma, and lymphoma. Epidemiological and experimental studies suggest that H. pylori chronic infection may be related to different extragastric diseases, including colorectal neoplasms. This concise review aims to explore the association of H. pylori infection with colorectal cancer and adenoma, including the recent epidemiological findings, the diagnostic methods employed to detect H. pylori and virulent factors, and the potentially involved mechanisms. Furthermore, is attempted to establish the current data integration for causal inference using the Bradford-Hill causality criteria. The weak, although global, strength of the epidemiological positive association between H. pylori infection and colonic neoplasms associated to new mechanisms postulated to explain this interaction, including intestinal dysbiosis, should stimulate future studies. Prospective confirmatory studies to establish the role of H. pylori eradication in the process of carcinogenic transformation of the colonic epithelium may define its eventual role in the treatment and prevention of colonic neoplasms.

RESUMO Helicobacter pylori é o principal agente etiológico dos tumores malignos causados por doenças infecciosas. Constitui fator importante, às vezes dominante, na patogênese de um amplo espectro de doenças como gastrite aguda e crônica, úlceras gástricas e duodenais, carcinoma gástrico e linfoma. Estudos epidemiológicos e experimentais sugerem que a infecção crônica por H. pylori pode estar relacionada a diferentes doenças extragástricas, incluindo neoplasias colorretais. Esta concisa revisão tem como objetivo explorar a associação da infecção por H. pylori com câncer colorretal e adenoma, incluindo os recentes achados epidemiológicos, os métodos de diagnóstico empregados para detectar H. pylori e seus fatores de virulência com os mecanismos potencialmente envolvidos nesta relação. Além disso, procura-se estabelecer a integração dos dados atuais na busca de inferência causal com o emprego dos critérios de causalidade de Bradford-Hill. A associação epidemiológica positiva entre infecção por H. pylori e neoplasias do cólon embora classificada como fraca - porém global - do ponto de vista epidemiológico, quando associada a mecanismos recentemente postulados para explicar essa interação, incluindo disbiose intestinal, deverá estimular a realização de investigações futuras. Estudos prospectivos confirmatórios para estabelecer o papel da erradicação do H. pylori no processo de transformação carcinogênica do epitélio do cólon são aguardados para definir seu eventual papel no tratamento e prevenção de neoplasias do cólon.

Circulating Leptin Levels as a Potential Biomarker in Inflammatory Bowel Diseases: A Systematic Review and Meta-Analysis.

BACKGROUND: The differential diagnosis of inflammatory bowel diseases (IBDs) between Crohn's disease (CD) and ulcerative colitis (UC) is important for designing an effective therapeutic regimen. However, without any adequate gold standard method for differential diagnosis currently, therapeutic design remains a major challenge in clinical practice. In this context, recent studies have showed that circulating leptin stands out as a potential biomarker for the categorization of IBDs. Thus, we aimed to summarize the current understanding of the prognostic and diagnostic value of serum leptin in patients with IBDs. METHODS: A systematic search was performed in PubMed/MEDLINE, Scopus, Cochrane Library, and Web of Science databases. Articles that aimed to study the relationship between circulating levels of leptin and IBDs were included. Finally, the meta-analysis was performed with the mean serum leptin levels in patients with IBDs and healthy controls using RevMan 5.3 software, with I2 > 50% as a criterion for substantial heterogeneity. RESULTS: Nineteen studies were included. Serum leptin levels among patients with IBDs and healthy controls did not show a significant difference (95% CI, -2.15 to 0.57; I2, 86%, P ≤ 0.00001). Similarly, there was no association of leptin levels with the activity of IBDs (95% CI, -0.24 to 0.06; I2, 50%; P = 0.13). However, serum leptin levels were significantly higher in patients with CD than those in patients with UC (95% CI, -2.09 to -0.37; I2, 7%; P ≤ 0.36). CONCLUSION: This review suggested that serum leptin levels might be a promising biomarker to help in the differentiation between CD and UC.

STRUCTURING A FECAL MICROBIOTA TRANSPLANTATION CENTER IN A UNIVERSITY HOSPITAL IN BRAZIL.

BACKGROUND: Fecal microbiota transplantation (FMT) is an important therapeutic option for recurrent or refractory Clostridioides difficile infection, being a safe and effective method. Initial results suggest that FMT also plays an important role in other conditions whose pathogenesis involves alteration of the intestinal microbiota. However, its systematized use is not widespread, especially in Brazil. In the last decade, multiple reports and several cases emerged using different protocols for FMT, without standardization of methods and with variable response rates. In Brazil, few isolated cases of FMT have been reported without the implantation of a Fecal Microbiota Transplantation Center (FMTC). OBJECTIVE: The main objective of this study is to describe the process of implanting a FMTC with a stool bank, in a Brazilian university hospital for treatment of recurrent and refractory C. difficile infection. METHODS: The center was structured within the criteria required by international organizations such as the Food and Drug Administration, the European Fecal Microbiota Transplant Group and in line with national epidemiological and regulatory aspects. RESULTS: A whole platform involved in structuring a transplant center with stool bank was established. The criteria for donor selection, processing and storage of samples, handling of recipients before and after the procedure, routes of administration, short and long-term follow-up of transplant patients were determined. Donor selection was conducted in three stages: pre-screening, clinical evaluation and laboratory screening. Most of the candidates were excluded in the first (75.4%) and second stage (72.7%). The main clinical exclusion criteria were: recent acute diarrhea, overweight (body mass index ≥25 kg/m2) and chronic gastrointestinal disorders. Four of the 134 candidates were selected after full screening, with a donor detection rate of 3%. CONCLUSION: The implantation of a transplant center, unprecedented in our country, allows the access of patients with recurrent or refractory C. difficile infection to innovative, safe treatment, with a high success rate and little available in Brazil. Proper selection of qualified donors is vital in the process of implementing a FMTC. The rigorous clinical evaluation of donors allowed the rational use of resources. A transplant center enables treatment on demand, on a larger scale, less personalized, with more security and traceability. This protocol provides subsidies for conducting FMT in emerging countries.

Estruturação de centro de transplante de microbiota fecal em hospital universitário no Brasil / Structuring a fecal microbiota transplantation center in a university hospital in brazil

ABSTRACT BACKGROUND: Fecal microbiota transplantation (FMT) is an important therapeutic option for recurrent or refractory Clostridioides difficile infection, being a safe and effective method. Initial results suggest that FMT also plays an important role in other conditions whose pathogenesis involves alteration of the intestinal microbiota. However, its systematized use is not widespread, especially in Brazil. In the last decade, multiple reports and several cases emerged using different protocols for FMT, without standardization of methods and with variable response rates. In Brazil, few isolated cases of FMT have been reported without the implantation of a Fecal Microbiota Transplantation Center (FMTC). OBJECTIVE: The main objective of this study is to describe the process of implanting a FMTC with a stool bank, in a Brazilian university hospital for treatment of recurrent and refractory C. difficile infection. METHODS: The center was structured within the criteria required by international organizations such as the Food and Drug Administration, the European Fecal Microbiota Transplant Group and in line with national epidemiological and regulatory aspects. RESULTS: A whole platform involved in structuring a transplant center with stool bank was established. The criteria for donor selection, processing and storage of samples, handling of recipients before and after the procedure, routes of administration, short and long-term follow-up of transplant patients were determined. Donor selection was conducted in three stages: pre-screening, clinical evaluation and laboratory screening. Most of the candidates were excluded in the first (75.4%) and second stage (72.7%). The main clinical exclusion criteria were: recent acute diarrhea, overweight (body mass index ≥25 kg/m2) and chronic gastrointestinal disorders. Four of the 134 candidates were selected after full screening, with a donor detection rate of 3%. CONCLUSION: The implantation of a transplant center, unprecedented in our country, allows the access of patients with recurrent or refractory C. difficile infection to innovative, safe treatment, with a high success rate and little available in Brazil. Proper selection of qualified donors is vital in the process of implementing a FMTC. The rigorous clinical evaluation of donors allowed the rational use of resources. A transplant center enables treatment on demand, on a larger scale, less personalized, with more security and traceability. This protocol provides subsidies for conducting FMT in emerging countries.

RESUMO CONTEXTO: O Transplante de microbiota fecal (TMF) é uma importante opção terapêutica para a infecção recorrente ou refratária pelo Clostridioides difficile, sendo método seguro e eficaz. Resultados iniciais sugerem que o TMF também desempenha papel relevante em outras afecções cuja patogênese envolve a alteração da microbiota intestinal. No entanto, seu uso sistematizado é pouco difundido, especialmente no Brasil. Na última década, surgiram múltiplos relatos e séries de casos utilizando diferentes protocolos para o TMF, sem padronização de métodos e com taxas de resposta variáveis. No Brasil, poucos casos isolados de TMF foram relatados sem a implantação de um Centro de Transplante de Microbiota Fecal (CTMF). OBJETIVO: O principal objetivo deste estudo foi descrever o processo de implantação de um CTMF com banco de fezes, em hospital universitário brasileiro, para tratamento de infecção recorrente e refratária pelo C. difficile. MÉTODOS: O CTMF foi estruturado dentro dos critérios exigidos e aprovados por organismos internacionais como o Food and Drug Administration, Grupo Europeu de Transplante de Microbiota Fecal e em consonância com os aspectos epidemiológicos e regulatórios nacionais. RESULTADOS: Foi estabelecida toda uma plataforma envolvida na estruturação de um centro de transplante com fezes congeladas. Determinou-se os critérios para seleção de doadores, processamento e armazenamento de amostras, manejo dos receptores antes e após o procedimento, uniformização de vias de administração do substrato fecal e seguimento a curto e longo prazo dos pacientes transplantados. A seleção dos doadores foi conduzida em três etapas: pré-triagem, avaliação clínica e exames laboratoriais. Boa parte dos candidatos foram excluídos na primeira (75,4%) e segunda etapa (72,7%). Os principais critérios clínicos de exclusão foram: diarreia aguda recente, excesso de peso (IMC ≥25 kg/m2) e distúrbios gastrointestinais crônicos. Quatro dos 134 candidatos foram selecionados após a triagem completa, com taxa de detecção de doadores de 3%. CONCLUSÃO: A implantação de um CTMF, inédito no nosso meio, possibilita o acesso de pacientes com infecção recorrente e refratária pelo C. difficile a tratamento inovador, seguro, com elevada taxa de sucesso e pouco disponível no Brasil. A seleção apropriada de doadores qualificados é vital no processo de implantação de um CTMF. A avaliação clínica rigorosa dos doadores permitiu o uso racional de recursos para realização de exames laboratoriais. Um CTMF possibilita tratamento sob demanda, em maior escala, menos personalizados, com mais segurança e rastreabilidade. Este protocolo fornece subsídios para a realização de TMF em países emergentes.

The diffuse-type gastric cancer epidemiology enigma.

BACKGROUND: Intestinal and diffuse gastric adenocarcinomas differ in clinical, epidemiological and molecular features. However, most of the concepts related to the intestinal-type are translated to gastric adenocarcinoma in general; thus, the peculiarities of the diffuse-type are underappreciated. RESULTS: Besides its growing importance, there are many gaps about the diffuse-type carcinogenesis and, as a result, its epidemiologic and pathogenetic features remain poorly understood. CONCLUSIONS: Alternative hypotheses to explain these features are discussed, including the role of the gastric microbiota, medical therapies, and modifications in the stomach's microenvironment.

PROSPECTIVE STUDY FOR VALIDATION OF A SINGLE PROTOCOL FOR THE 13C-UREA BREATH TEST USING TWO DIFFERENT DEVICES IN THE DIAGNOSIS OF H. PYLORI INFECTION.

BACKGROUND: 13C-urea breath test (UBT) is the gold-standard, noninvasive method for H. pylori diagnosis. However, there is no uniform standardization of the test. This situation can be unpractical for laboratories running with two or more devices. OBJECTIVE: To perform a prospective comparison validation study of UBT employing one validated protocol for two different devices: BreathID Hp Lab System® (Exalenz Bioscience Ltd, Israel), here called device A and IRIS-Doc2® (Wagner Analysen-Technik, Germany, now Mayoly Spindler Group, France), here called device B, in the diagnosis of H. pylori infection. METHODS: A total of 518 consecutive patients (365 females, 153 males, mean age 53 years) referred for UBT were included. All patients received device A protocol as follow: after at least one hour fasting, patients filled two bags prior to the test, then ingested an aqueous solution containing 75 mg of 13C-urea with a 4.0 g citric acid powder and filled another two bags 15 min after ingesting the test solution. One pair of breath sample bags (before and after ingestion) was analyzed by the two different devices. A delta over baseline (DOB) ≥5‰ indicated H. pylori infection. Statistics: Wilcoxon test, kappa coefficient with 95% CI, Wilson's method. RESULTS: Considering the device A protocol as the gold standard, its comparison with device B showed a sensitivity of 99.3% (95% CI: 96.3-99.9) and a specificity of 98.9% (95% CI: 97.3-99.6). Kappa coefficient was 0.976 (95% IC: 0.956-0.997). CONCLUSION: Correlation between the two devices was excellent and supports a uniform standardization of UBT.

Estudo prospectivo para validação de protocolo único para o teste respiratório com ureia marcada com carbono-13 empregando dois dispositivos diferentes, no diagnóstico da infecção por H. pylori / Prospective study for validation of a single protocol for the 13c-urea breath test using two different devices in the diagnosis of h. pylori infection

ABSTRACT BACKGROUND: 13C-urea breath test (UBT) is the gold-standard, noninvasive method for H. pylori diagnosis. However, there is no uniform standardization of the test. This situation can be unpractical for laboratories running with two or more devices. OBJECTIVE: To perform a prospective comparison validation study of UBT employing one validated protocol for two different devices: BreathID Hp Lab System® (Exalenz Bioscience Ltd, Israel), here called device A and IRIS-Doc2® (Wagner Analysen-Technik, Germany, now Mayoly Spindler Group, France), here called device B, in the diagnosis of H. pylori infection. METHODS: A total of 518 consecutive patients (365 females, 153 males, mean age 53 years) referred for UBT were included. All patients received device A protocol as follow: after at least one hour fasting, patients filled two bags prior to the test, then ingested an aqueous solution containing 75 mg of 13C-urea with a 4.0 g citric acid powder and filled another two bags 15 min after ingesting the test solution. One pair of breath sample bags (before and after ingestion) was analyzed by the two different devices. A delta over baseline (DOB) ≥5‰ indicated H. pylori infection. Statistics: Wilcoxon test, kappa coefficient with 95% CI, Wilson's method. RESULTS: Considering the device A protocol as the gold standard, its comparison with device B showed a sensitivity of 99.3% (95% CI: 96.3-99.9) and a specificity of 98.9% (95% CI: 97.3-99.6). Kappa coefficient was 0.976 (95% IC: 0.956-0.997). CONCLUSION: Correlation between the two devices was excellent and supports a uniform standardization of UBT.

RESUMO CONTEXTO: O teste respiratório com ureia-marcada com carbono-13 (TR-13C) é o método padrão-ouro para o diagnóstico não invasivo da infecção por H. pylori. Apesar disto, não existe uma uniformização de protocolos para a sua realização, trazendo dificuldades operacionais para laboratórios ou clínicas que operam com equipamentos de fabricantes diferentes. OBJETIVO: Estudo prospectivo e comparativo para validação do TR-13C para o diagnóstico de infecção por H. pylori, com emprego de protocolo único para dois equipamentos diferentes, a saber: BreathID Hp Lab System® (Exalenz Bioscience Ltd, Israel), aqui denominado equipamento A e IRIS-Doc2® (Wagner Analysen-Technik, Alemanha, agora Mayoly Spindler Group, França), aqui denominado equipamento B. MÉTODOS: Um total de 518 pacientes (365 mulheres e 153 homens, idade média de 53 anos) consecutivamente encaminhados para a realização do TR-13C foram incluídos no estudo. Todos os participantes realizaram TR-13C, que foi processado e analisado simultaneamente pelos dois equipamentos. Embora os dois equipamentos possuam protocolos independentes previamente validados, foi optado, por sua maior praticidade, pela utilização de um único protocolo, conforme recomendado pelo fabricante do equipamento A, e assim resumido: após jejum mínimo de 1h, foram amostras de ar expirado coletadas em dois pequenos sacos coletores (120 mL), correspondendo ao tempo-zero (amostra-1, controle). Em seguida, os pacientes ingeriram, em até 2 min, uma solução aquosa (200 mL) contendo 75 mg de 13C-ureia e 4,0 gramas de ácido cítrico em pó, adicionado com edulcorante. Uma segunda coleta de ar expirado era realizada 15 min após a ingestão do substrato em dois novos pequenos sacos coletores, correspondendo à amostra-2. Foram considerados positivos para a presença da infecção por H. pylori quando apresentavam um delta over baseline (DOB) igual ou maior que 5‰. Análise estatística foi realizada com o teste de Wilcoxon, coeficiente kappa com IC 95% e método de Wilson. RESULTADOS: Considerando o protocolo do equipamento A como o padrão-ouro, sua comparação com o equipamento B mostrou sensibilidade de 99,3% (IC 95%: 96,3-99,9) e especificidade de 98,9% (IC 95%: 97,3-99,6). O coeficiente kappa observado foi de 0,976 (IC 95%: 0,956-0,997). CONCLUSÃO: A correlação entre os dois equipamentos foi excelente e contribui para uma uniformização de protocolos para TR-13C.

Suicide journey of H. pylori through gastric carcinogenesis: the role of non-H. pylori microbiome and potential consequences for clinical practice.

Despite being one of the most studied cancer-related infections, the relationship between Helicobacter pylori infection and gastric adenocarcinoma (GC) remains, in some points, obscure. Based on a critical analysis of the available literature regarding stomach microbiota, we aimed to shed light to a possible new interpretation of the current understanding about the Helicobacter pylori-related GC carcinogenesis. We analyzed data from the literature on Helicobacter pylori and other potential carcinogenic pathogens, in both benignant conditions and gastric adenocarcinoma. Helicobacter pylori is the dominant microorganism in benignant conditions as non-complicated gastritis. In atrophic gastritis, metaplasia and, mainly, in gastric adenocarcinoma, a strong reduction in Helicobacter pylori abundance, and increased occurrence of other microorganisms is strongly demonstrated by metagenomic experiments. While causing peptic disease and keeping the stomach's high acidity, Helicobacter pylori infection avoids gastric infection by carcinogenic intestinal microbiota. Nevertheless, Helicobacter pylori persistence may also provoke an atrophic gastritis, a condition that causes its own decline, due to a microenvironment modification, including reduced acidity, resulting in Helicobacter pylori substitution by a cancer-prone microbiota. This new interpretation might result in a dramatic modification on clinical management of Helicobacter pylori-related gastric disease.

Identification of DNA mutations in gastric washes from gastric adenocarcinoma patients: Possible implications for liquid biopsies and patient follow-up.

Whereas cancer patients have benefited from liquid biopsies, the scenario for gastric adenocarcinoma (GAC) is still dismal. We used next-generation deep sequencing of TP53-a highly mutated and informative gene in GAC-to assess mutations in tumor biopsies, plasma (PL) and stomach fluids (gastric wash-GW). We evaluated their potential to reveal tumor-derived mutations, useful for monitoring mutational dynamics at diagnosis, progression and treatment. Exon-capture libraries were constructed from 46 patients including tumor biopsies, GW and PL pre and post-treatment (196 samples), with high vertical coverage >8,000×. At diagnosis, we detected TP53 mutations in 15/46 biopsies (32.6%), 7/46 GW- (15.2%) and 6/46 PL-samples (13%). Biopsies and GW were concordant in 38/46 cases (82.6%) for the presence/absence of mutations and, furthermore, four GW-exclusive mutations were identified, suggesting tumor heterogeneity. Considering the combined analysis of GW and PL, TP53 mutations found in biopsies were also identified in 9/15 (60%) of cases, the highest detection level reported for GAC. Our study indicates that GW could be useful to track DNA alterations, especially if anchored to a comprehensive gene-panel designed for this malignancy.

IVTH BRAZILIAN CONSENSUS CONFERENCE ON HELICOBACTER PYLORI INFECTION.

Significant progress has been obtained since the III Brazilian Consensus Conference on H. pylori infection held in 2012, in Bento Gonçalves, Brazil, and justify a fourth meeting to establish updated guidelines on the current management of H. pylori infection. Therefore, the Núcleo Brasileiro para Estudo do Helicobacter pylori e Microbiota (NBEHPM), association linked to Brazilian Federation of Gastroenterology (FBG) held its fourth meeting again in Bento Gonçalves, RS, Brazil, on August 25-27, 2017. Twenty-six delegates, including gastroenterologists, endoscopists, and pathologists from the five regions of Brazil as well as one international guest from the United States, participated in the meeting. The participants were invited based on their knowledge and contribution to the study of H. pylori infection. The meeting sought to review different aspects of treatment for infection; establish a correlation between infection, dyspepsia, intestinal microbiota changes, and other disorders with a special emphasis on gastric cancer; and reassess the epidemiological and diagnostic aspects of H. pylori infection. Participants were allocated into four groups as follows: 1) Epidemiology and Diagnosis, 2) Dyspepsia, intestinal microbiota and other afections, 3) Gastric Cancer, and, 4) Treatment. Before the consensus meeting, participants received a topic to be discussed and prepared a document containing a recent literature review and statements that should be discussed and eventually modified during the face-to-face meeting. All statements were evaluated in two rounds of voting. Initially, each participant discussed the document and statements with his group for possible modifications and voting. Subsequently, during a second voting in a plenary session in the presence of all participants, the statements were voted upon and eventually modified. The participants could vote using five alternatives: 1) strongly agree; 2) partially agree; 3) undecided; 4) disagree; and 5) strongly disagree. The adopted consensus index was that 80% of the participants responded that they strongly or partially agreed with each statement. The recommendations reported are intended to provide the most current and relevant evidences to management of H. pylori infection in adult population in Brazil.

Expression of the c-MET, HGF and VEGF biomarkers in intestinal and diffuse gastric cancer in the Brazilian population: a pilot study for the standardization of the quantitative PCR technique

Background: Gastric carcinoma (GC) is the third leading cause of death among malignant tumors worldwide, causing approximately 900,000 deaths/year. Changes in oncogenes that encode tyrosine kinase receptors play an important role in the pathogenesis of GC. MET gene is a proto-oncogene that encodes a tyrosine kinase receptor c-MET and it is required for embryonic development and tissue repair. The hepatocyte growth factor (HGF) is the only known ligand for c-Met receptor. The MET oncogene activation suppresses apoptosis and promotes the survival, proliferation, migration, differentiation and angiogenesis of cells. Among the angiogenic factors, VEGF is the main regulator. Its biological function includes the promotion of endothelial cells mitosis to stimulate cells proliferation. These biomarkers expression in GC is relatively recent and population-based studies are required to define the expression pattern. The aim of this study was to determine qPCR technical standardization to evaluate quantitatively, in paraffin tissue samples, the presence of gene 23 expression of the MET, HGF and VEGF in diffuse and intestinal GC types. Methods: Twenty GC patients were studied, 10 patients were intestinal-type GC (average age 72.1 years) and 10 diffuse-type (average age 50.1 years). In all patients, tissue samples were analyzed from the tumor and distant areas of the tumor tissue. The relative expressions of the tumor markers c-Met, HGF and VEGF were performed by qPCR technique by comparing tumor and non-tumoral samples and they were normalized with the GAPDH constitutive gene. Statistical analysis was performed through T-test. Results: For c-Met, 18/20 (90%) patients expressed the marker and 9/20 (45%) overexpressed this gene, in which three were intestinal-type GC and six were diffuse-type GC. For HGF, only 7/20 (35%) patients expressed this gene and it was overexpressed in 4/20 (20%), in which two were intestinal-type GC and two were diffuse-type GC. For VEGF, 20/20 (100%) patients expressed this marker and in 12/20 (60%) were observed overexpression, in which eight patients had diffuse-type GC and four had intestinal-type GC. Conclusions: qPCR technique was standardized and suitable for expression analysis of the three biomarkers using paraffin embedded tissue samples. Further studies should be carried out to characterize the expression pattern of these biomarkers in GC in the Brazilian population (AU)

MOLECULAR DETECTION OF CLARITHROMYCIN AND FLUOROQUINOLONES RESISTANCE IN HELICOBACTER PYLORI INFECTION, DIRECTLY APPLIED TO GASTRIC BIOPSIES, IN AN URBAN BRAZILIAN POPULATION.

BACKGROUND: - Antimicrobial resistance is the major factor leading to eradication failure in H. pylori treatment. Molecular tests are useful to detect genetic mutations predictive of clarithromycin and fluoroquinolones resistance. Knowledge of the local prevalence rate of resistance is important to define the best recommended treatment. OBJECTIVE: - To assess the prevalence of primary resistance of H. pylori to clarithromycin and fluoroquinolones, using a molecular test, in a Southeastern urban Brazilian population. METHODS: - A total of 72 H. pylori seropositive patients [65% female, mean age 39 (19-73) years] never treated before for this infection were studied. All patients underwent gastroscopy in addition to antrum and corpus biopsies and molecular test GenoType HelicoDR (Hain Life Science, Germany) to detect H. pylori and point mutations in genes responsible for clarithromycin and fluoroquinolone resistance. The molecular procedure was divided into three steps: DNA extraction from biopsy samples, a multiplex amplification with biotinylated primers and a reverse hybridization. The most frequent point mutations involved in resistance to the two antibiotics were evaluated. RESULTS: - Resistance to clarithromycin was detected in nine (12.5%) patients and to fluoroquinolones in eight (11.1%) patients. The point mutation A2147G was the most common (77.8%) among resistant strains to clarithromycin. In 50% of the resistant strains to fluoroquinolones, the mutant codon couldn't be identified. CONCLUSION: - The resistance rates to clarithromycin and fluorquinolones in a large urban population in the Southeast of Brazil were acceptable, suggesting that these drugs remain appropriate options to first and second-line of H. pylori treatment. The molecular test represents an adequate diagnostic tool for monitoring H. pylori resistance.

Molecular detection of clarithromycin and fluoroquinolones resistance in helicobacter pylori infection, directly applied to gastric biopsies, in an urban brazilian population

ABSTRACT Background - Antimicrobial resistance is the major factor leading to eradication failure in H. pylori treatment. Molecular tests are useful to detect genetic mutations predictive of clarithromycin and fluoroquinolones resistance. Knowledge of the local prevalence rate of resistance is important to define the best recommended treatment. Objective - To assess the prevalence of primary resistance of H. pylori to clarithromycin and fluoroquinolones, using a molecular test, in a Southeastern urban Brazilian population. Methods - A total of 72 H. pylori seropositive patients [65% female, mean age 39 (19-73) years] never treated before for this infection were studied. All patients underwent gastroscopy in addition to antrum and corpus biopsies and molecular test GenoType HelicoDR (Hain Life Science, Germany) to detect H. pylori and point mutations in genes responsible for clarithromycin and fluoroquinolone resistance. The molecular procedure was divided into three steps: DNA extraction from biopsy samples, a multiplex amplification with biotinylated primers and a reverse hybridization. The most frequent point mutations involved in resistance to the two antibiotics were evaluated. Results - Resistance to clarithromycin was detected in nine (12.5%) patients and to fluoroquinolones in eight (11.1%) patients. The point mutation A2147G was the most common (77.8%) among resistant strains to clarithromycin. In 50% of the resistant strains to fluoroquinolones, the mutant codon couldn't be identified. Conclusion - The resistance rates to clarithromycin and fluorquinolones in a large urban population in the Southeast of Brazil were acceptable, suggesting that these drugs remain appropriate options to first and second-line of H. pylori treatment. The molecular test represents an adequate diagnostic tool for monitoring H. pylori resistance.

RESUMO Contexto - A resistência aos antimicrobianos é o principal fator associado à falha terapêutica no tratamento do H. pylori. Testes moleculares são úteis na detecção das mutações genéticas associadas ao desenvolvimento de resistência à claritromicina e fluorquinolonas. O conhecimento da taxa de prevalência local de resistência é importante na definição do melhor esquema terapêutico. Objetivo - Estimar a prevalência de resistência primária do H. pylori à claritromicina e fluorquinolonas, empregando-se um teste molecular, em uma capital do Sudeste do Brasil. Métodos - Setenta e dois pacientes com sorologia positiva para H. pylori [65% mulheres, idade média 39 (19-73) anos], nunca tratados previamente para essa infecção, foram selecionados. Todos os pacientes submeteram-se à endoscopia digestiva com biópsias de antro e corpo e realização do teste molecular GenoType HelicoDR (Hain Life Science, Alemanha) para a detecção do H. pylori e das mutações pontuais dos genes responsáveis pela resistência à claritromicina e fluorquinolonas. O procedimento molecular constituía-se de três etapas: extração do DNA a partir das amostras endoscópicas, amplificação multiplex com primers biotinilados e hibridização reversa. As mutações pontuais mais frequentemente envolvidas com resistência aos dois antibióticos foram avaliadas. Resultados - Resistência à claritromicina foi detectada em nove (12,5%) pacientes e às fluorquinolonas em oito (11,1%) pacientes. A mutação pontual A2147G foi a mais comum (77,8%) entre as cepas resistentes à claritromicina. Em 50% das cepas resistentes à fluorquinolonas, o códon mutante não pôde ser identificado. Conclusão - As taxas de resistência à claritromicina (12,5%) e às fluorquinolonas (11,1%), em uma importante capital do Sudeste do Brasil, mostraram índices aceitáveis, sugerindo que essas drogas permanecem opções apropriadas para o tratamento de primeira e segunda linha do H. pylori. O teste molecular constitui uma ferramenta diagnóstica adequada para monitorar a resistência do H. pylori.

Helicobacter pylori and t(11;18)(q21;q21) translocation in gastric malt lymphoma.

CONTEXT: Gastric mucosa-associated lymphoid tissue (MALT) lymphoma is clearly associated with Helicobacter pylori gastritis and can be cured with anti- H pylori therapy alone. The presence of t(11;18)(q21;q21) translocation is thought to predict a lower response rate to anti- H pylori treatment. OBJECTIVES: To study the presence of t(11;18)(q21;q21) genetic translocation and its clinical impact in low-grade gastric MALT lymphoma Brazilian patients. METHODS: A consecutive series of eight patients with gastric MALT lymphoma were submitted to gastroscopy, endoscopic ultrasound, histopathological examination, H pylori search and RT-PCR-based methodology. All patients received anti-H pylori treatment. Eradicated patients were followed-up every 3-6 months for 2 years. RESULTS: Eight patients were studied. All patients had tumor involvement restricted to the mucosa or submucosa and seven patients had low-grade gastric MALT lymphoma. All infected patients achieved H pylori eradication. Histological tumor regression was observed in 5/7 (71%) of the low-grade gastric MALT lymphoma patients. The presence of t(11;18)(q21;q21) translocation was found in 4 (57%) of these patients; among them only two had histological tumor regression following H pylori eradication. CONCLUSIONS: RT-PCR is a feasible and efficient method to detect t(11;18)(q21;q21) translocation, being carried out in routine molecular biology laboratories. The early detection of such translocation can be very helpful for better targeting the therapy to be applied to gastric MALT lymphoma patients.

HELICOBACTER PYLORI AND t(11;18)(q21;q21) TRANSLOCATION IN GASTRIC MALT LYMPHOMA / Helicobacter pylori e presença de translocação t(11;18)(q21;q21) em pacientes portadores de linfoma MALT gástrico

Context Gastric mucosa-associated lymphoid tissue (MALT) lymphoma is clearly associated with Helicobacter pylori gastritis and can be cured with anti- H pylori therapy alone. The presence of t(11;18)(q21;q21) translocation is thought to predict a lower response rate to anti- H pylori treatment. Objectives To study the presence of t(11;18)(q21;q21) genetic translocation and its clinical impact in low-grade gastric MALT lymphoma Brazilian patients. Methods A consecutive series of eight patients with gastric MALT lymphoma were submitted to gastroscopy, endoscopic ultrasound, histopathological examination, H pylori search and RT-PCR-based methodology. All patients received anti-H pylori treatment. Eradicated patients were followed-up every 3-6 months for 2 years. Results Eight patients were studied. All patients had tumor involvement restricted to the mucosa or submucosa and seven patients had low-grade gastric MALT lymphoma. All infected patients achieved H pylori eradication. Histological tumor regression was observed in 5/7 (71%) of the low-grade gastric MALT lymphoma patients. The presence of t(11;18)(q21;q21) translocation was found in 4 (57%) of these patients; among them only two had histological tumor regression following H pylori eradication. Conclusions RT-PCR is a feasible and efficient method to detect t(11;18)(q21;q21) translocation, being carried out in routine molecular biology laboratories. The early detection of such translocation can be very helpful for better targeting the therapy to be applied to gastric MALT lymphoma patients. .

Contexto A patogênese do linfoma MALT (tecido linfoide associado à mucosa) gástrico, também conhecido como linfoma de zona marginal de células B, está claramente associada à gastrite por infecção pelo Helicobacter pylori e, a maioria desses tumores pode ser curada apenas com a erradicação da bactéria. A presença da translocação t(11;18)(q21;q21) tem sido identificada como a anomalia citogenética mais comum do linfoma MALT gástrico e sua presença pode prever uma menor taxa de resposta ao tratamento anti-H pylori. Objetivos Estudo da translocação genética t(11;18)(q21;q21) e seu impacto na evolução clínica de pacientes portadores de linfoma MALT gástrico de baixo grau. Métodos Uma série consecutiva de oito pacientes com linfoma MALT gástrico foi submetida à endoscopia digestiva, ultra-sonografia endoscópica, exame histopatológico, pesquisa do H pylori e metodologia rotineira de transcrição reversa seguida de reação em cadeia da polimerase (RT-PCR) utilizando primers específicos para API2-MALT1. Todos os pacientes receberam tratamento anti-H pylori e retratamento, quando necessário. Após a erradicação, exames endoscópicos foram realizados a cada 3-6 meses durante 2 anos para acompanhamento da evolução do tumor. Resultados Foram estudados oito pacientes (seis mulheres, idade média: 57 anos). Todos apresentavam à ecoendoscopia envolvimento tumoral restrito à mucosa ou submucosa com aparência endoscópica variável. A histologia mostrou que sete pacientes tinham linfoma MALT gástrico de baixo grau e um de alto grau. A erradicação do H pylori foi obtida em todos os pacientes, embora a bactéria não tenha sido identificada em um deles. Foi observada regressão histológica ...