Endoscopic part-task training box scores correlate with endoscopic outcomes.

BACKGROUND: Competency in endoscopy has traditionally been based on number of procedures performed. With movement towards milestone-based accreditation, new standards of establishing competency are required. The Thompson Endoscopic Skills Trainer (TEST) is a training device previously shown to differentiate between novice and expert endoscopists. This study aims to correlate TEST scores to other markers of performance in endoscopy. METHODS: Trainees of a gastroenterology fellowship program were guided through the TEST. Their scores and sub-scores were correlated to their endoscopic metrics of performance, including adenoma detection rate, cecal intubation rate, cecal intubation time, withdrawal time, fentanyl usage, midazolam usage, pain score, overall procedure time, and performance on the ASGE Assessment of Competency in Endoscopy Tool (ACE Tool). RESULTS: The Overall Score positively correlated with the ACE Tool Total Score (r = 0.707, p = 0.010) and sub-scores (Cognitive Skills Score: r = 0.624, p = 0.030; Motor Skills Score: r = 0.756, p = 0.004), and negatively correlated with cecal intubation time (r = - 0.591, p = 0.043). The Gross Motor Score positively correlated with cecal intubation rate (r = 0.593, p = 0.042), ACE Tool Total Score (r = 0.594, p = 0.042) and Motor Skills Score (r = 0.623, p = 0.031), and negatively correlated with cecal intubation time (r = - 0.695, p = 0.012). The Fine Motor Score positively correlated with the ACE Tool Polypectomy Score (r = 0.601, p = 0.039), and negatively correlated with procedure time (r = - 0.640, p = 0.025), cecal intubation time (r = - 0.645, p = 0.024), and withdrawal time (r = - 0.629, p = 0.028). CONCLUSION: This study demonstrates that performance on the TEST correlate to endoscopic measures. Given these results, the TEST may be used in conjunction with existing assessment tools for demonstrating competency in endoscopy.

A Theory-based Educational Pamphlet With Low-residue Diet Improves Colonoscopy Attendance and Bowel Preparation Quality.

GOALS/BACKGROUND: Patients who "no-show" for colonoscopy or present with poor bowel preparation waste endoscopic resources and do not receive adequate examinations for colorectal cancer (CRC) screening. Using the Health Belief Model, we modified an existing patient education pamphlet and evaluated its effect on nonattendance rates and bowel preparation quality. STUDY: We implemented a color patient education pamphlet to target individual perceptions about CRC and changed bowel preparation instructions to include a low-residue diet instead of the previous clear liquid diet. We compared the nonattendance rate over a 2-month period before and after the introduction of the pamphlet, allowing for a washout period during which pamphlet use was inconsistent. We compared the Boston Bowel Preparation Scale (BBPS) in 100 consecutive patients who underwent colonoscopy during each of the 2 periods. RESULTS: Baseline characteristics between the 2 groups were similar, although patients who received the pamphlet were younger (P=0.03). The nonattendance rate was significantly lower in patients who received the pamphlet (13% vs. 21%, P=0.01). The percentage of patients with adequate bowel preparation increased from 82% to 86% after introduction of the pamphlet, although this was not statistically significant (P=0.44). The proportion of patients with a BBPS score of 9 was significantly higher in the pamphlet group (41% vs. 27%, P=0.03). There was no difference in adenoma and sessile serrated adenoma detection rates before and after pamphlet implementation. CONCLUSIONS: After implementing a theory-based patient education intervention with a low-residue diet, our absolute rate for colonoscopy nonattendance decreased by 8% and the proportion of patients with a BBPS score of 9 increased by 14%. The Health Belief Model appears to be a useful construct for CRC screening interventions.

Human Immunodeficiency Virus-Associated Diarrhea: Still an Issue in the Era of Antiretroviral Therapy.

Over half of patients with human immunodeficiency virus (HIV) experience diarrhea that contributes negatively to quality of life and adherence to antiretroviral therapy (ART). Opportunistic infectious agents that cause diarrhea in patients with HIV span the array of protozoa, fungi, viruses, and bacteria. With global use of ART, the incidence of diarrhea because of opportunistic infections has decreased; however, the incidence of noninfectious diarrhea has increased. The etiology of noninfectious diarrhea in patients with HIV is multifactorial and includes ART-associated diarrhea and gastrointestinal damage related to HIV infection (i.e., HIV enteropathy). A basic algorithm for the diagnosis of diarrhea in patients with HIV includes physical examination, a review of medical history, assessment of HIV viral load and CD4+ T cell count, stool microbiologic assessment, and endoscopic evaluation, if needed. For patients with negative diagnostic results, the diagnosis of noninfectious diarrhea may be considered. Pharmacologic options for the treatment of noninfectious diarrhea are primarily supportive; however, the use of many unapproved agents is based on unstudied and anecdotal information. In addition, these agents can be associated with treatment-limiting adverse events (AEs), such as drug-drug interactions with ART regimens, abuse liability, and additional gastrointestinal AEs. Currently, crofelemer, an antisecretory agent, is the only therapy approved in the USA for the symptomatic relief of noninfectious diarrhea in patients with HIV on ART.

Preferential HIV infection of CCR6+ Th17 cells is associated with higher levels of virus receptor expression and lack of CCR5 ligands.

Th17 cells are enriched in the gut mucosa and play a critical role in maintenance of the mucosal barrier and host defense against extracellular bacteria and fungal infections. During chronic human immunodeficiency virus (HIV) infection, Th17 cells were more depleted compared to Th1 cells, even when the patients had low or undetectable viremia. To investigate the differential effects of HIV infection on Th17 and Th1 cells, a culture system was used in which CCR6(+) CD4(+) T cells were sorted from healthy human peripheral blood and activated in the presence of interleukin 1ß (IL-1ß) and IL-23 to drive expansion of Th17 cells while maintaining Th1 cells. HIV infection of these cultures had minimal effects on Th1 cells but caused depletion of Th17 cells. Th17 loss correlated with greater levels of virus-infected cells and cell death. In identifying cellular factors contributing to higher susceptibility of Th17 cells to HIV, we compared Th17-enriched CCR6(+) and Th17-depleted CCR6(-) CD4 T cell cultures and noted that Th17-enriched CCR6(+) cells expressed higher levels of α4ß7 and bound HIV envelope in an α4ß7-dependent manner. The cells also had greater expression of CD4 and CXCR4, but not CCR5, than CCR6(-) cells. Moreover, unlike Th1 cells, Th17 cells produced little CCR5 ligand, and transfection with one of the CCR5 ligands, MIP-1ß (CCL4), increased their resistance against HIV. These results indicate that features unique to Th17 cells, including higher expression of HIV receptors and lack of autocrine CCR5 ligands, are associated with enhanced permissiveness of these cells to HIV.

Absence of HIV-1 evolution in the gut-associated lymphoid tissue from patients on combination antiviral therapy initiated during primary infection.

Mucosal mononuclear (MMC) CCR5+CD4+ T cells of the gastrointestinal (GI) tract are selectively infected and depleted during acute HIV-1 infection. Despite early initiation of combination antiretroviral therapy (cART), gut-associated lymphoid tissue (GALT) CD4+ T cell depletion and activation persist in the majority of HIV-1 positive individuals studied. This may result from ongoing HIV-1 replication and T-cell activation despite effective cART. We hypothesized that ongoing viral replication in the GI tract during cART would result in measurable viral evolution, with divergent populations emerging over time. Subjects treated during early HIV-1 infection underwent phlebotomy and flexible sigmoidoscopy with biopsies prior to and 15-24 months post initiation of cART. At the 2(nd) biopsy, three GALT phenotypes were noted, characterized by high, intermediate and low levels of immune activation. A representative case from each phenotype was analyzed. Each subject had plasma HIV-1 RNA levels <50 copies/ml at 2(nd) GI biopsy and CD4+ T cell reconstitution in the peripheral blood. Single genome amplification of full-length HIV-1 envelope was performed for each subject pre- and post-initiation of cART in GALT and PBMC. A total of 280 confirmed single genome sequences (SGS) were analyzed for experimental cases. For each subject, maximum likelihood phylogenetic trees derived from molecular sequence data showed no evidence of evolved forms in the GALT over the study period. During treatment, HIV-1 envelope diversity in GALT-derived SGS did not increase and post-treatment GALT-derived SGS showed no substantial genetic divergence from pre-treatment sequences within transmitted groups. Similar results were obtained from PBMC-derived SGS. Our results reveal that initiation of cART during acute/early HIV-1 infection can result in the interruption of measurable viral evolution in the GALT, suggesting the absence of de-novo rounds of HIV-1 replication in this compartment during suppressive cART.

Recognition of bacterial glycosphingolipids by natural killer T cells.

Natural killer T (NKT) cells constitute a highly conserved T lymphocyte subpopulation that has the potential to regulate many types of immune responses through the rapid secretion of cytokines. NKT cells recognize glycolipids presented by CD1d, a class I-like antigen-presenting molecule. They have an invariant T-cell antigen receptor (TCR) alpha-chain, but whether this invariant TCR recognizes microbial antigens is still controversial. Here we show that most mouse and human NKT cells recognize glycosphingolipids from Sphingomonas, Gram-negative bacteria that do not contain lipopolysaccharide. NKT cells are activated in vivo after exposure to these bacterial antigens or bacteria, and mice that lack NKT cells have a marked defect in the clearance of Sphingomonas from the liver. These data suggest that NKT cells are T lymphocytes that provide an innate-type immune response to certain microorganisms through recognition by their antigen receptor, and that they might be useful in providing protection from bacteria that cannot be detected by pattern recognition receptors such as Toll-like receptor 4.

Primary HIV-1 infection is associated with preferential depletion of CD4+ T lymphocytes from effector sites in the gastrointestinal tract.

Given its population of CCR5-expressing, immunologically activated CD4(+) T cells, the gastrointestinal (GI) mucosa is uniquely susceptible to human immunodeficiency virus (HIV)-1 infection. We undertook this study to assess whether a preferential depletion of mucosal CD4(+) T cells would be observed in HIV-1-infected subjects during the primary infection period, to examine the anatomic subcompartment from which these cells are depleted, and to examine whether suppressive highly active antiretroviral therapy could result in complete immune reconstitution in the mucosal compartment. Our results demonstrate that a significant and preferential depletion of mucosal CD4(+) T cells compared with peripheral blood CD4(+) T cells is seen during primary HIV-1 infection. CD4(+) T cell loss predominated in the effector subcompartment of the GI mucosa, in distinction to the inductive compartment, where HIV-1 RNA was present. Cross-sectional analysis of a cohort of primary HIV-1 infection subjects showed that although chronic suppression of HIV-1 permits near-complete immune recovery of the peripheral blood CD4(+) T cell population, a significantly greater CD4(+) T cell loss remains in the GI mucosa, despite up to 5 yr of fully suppressive therapy. Given the importance of the mucosal compartment in HIV-1 pathogenesis, further study to elucidate the significance of the changes observed here is critical.

Perceptions of fecal microbiota transplantation for Clostridium difficile infection: factors that predict acceptance.

BACKGROUND: Despite the effectiveness of fecal microbiota transplantation (FMT) for treating recurrent Clostridium difficile (C. difficile) infection, some patients are reluctant to accept this therapy. Our study examined attitudes towards FMT and factors that contribute to patients' acceptance of this treatment. METHODS: We distributed patient surveys at a Veterans Affairs hospital, a public hospital, and an academic faculty practice. Multivariable logistic regression was performed, adjusting for factors associated with FMT acceptance on univariate analysis and prior experience with C. difficile infection. RESULTS: Of 267 patients, only 12% knew of FMT prior to the survey, but 77% would undergo the procedure if medically indicated. On multivariable analysis, those with children and with college degrees or higher were more likely to agree to FMT (odds ratio [OR] 2.11, 95% confidence interval [CI] 1.02-4.35; OR 2.27, 95% CI 1.11-4.60 respectively). Sixty-five respondents (71%) chose colonoscopy as the preferred vehicle for FMT, while nasogastric tube was least preferred. Disease transmission was the most common concern (30%, n=242), and FMT success rate was the least selected concern (9.1%). CONCLUSIONS: Most patients in a diverse sample of gastroenterology clinics had no prior knowledge of FMT, but were receptive to the procedure. Having children and higher education levels were predictors for FMT acceptance. Our findings suggest that barriers to FMT utilization may be overcome with counseling about safety concerns. More data on the risk of transmitting diseases or clinical characteristics, such as obesity, through FMT are needed and will be important for the acceptance of this procedure.

Integrated Analysis of Biopsies from Inflammatory Bowel Disease Patients Identifies SAA1 as a Link Between Mucosal Microbes with TH17 and TH22 Cells.

BACKGROUND: Inflammatory bowel diseases (IBD) are believed to be driven by dysregulated interactions between the host and the gut microbiota. Our goal is to characterize and infer relationships between mucosal T cells, the host tissue environment, and microbial communities in patients with IBD who will serve as basis for mechanistic studies on human IBD. METHODS: We characterized mucosal CD4 T cells using flow cytometry, along with matching mucosal global gene expression and microbial communities data from 35 pinch biopsy samples from patients with IBD. We analyzed these data sets using an integrated framework to identify predictors of inflammatory states and then reproduced some of the putative relationships formed among these predictors by analyzing data from the pediatric RISK cohort. RESULTS: We identified 26 predictors from our combined data set that were effective in distinguishing between regions of the intestine undergoing active inflammation and regions that were normal. Network analysis on these 26 predictors revealed SAA1 as the most connected node linking the abundance of the genus Bacteroides with the production of IL17 and IL22 by CD4 T cells. These SAA1-linked microbial and transcriptome interactions were further reproduced with data from the pediatric IBD RISK cohort. CONCLUSIONS: This study identifies expression of SAA1 as an important link between mucosal T cells, microbial communities, and their tissue environment in patients with IBD. A combination of T cell effector function data, gene expression and microbial profiling can distinguish between intestinal inflammatory states in IBD regardless of disease types.

Lack of mucosal immune reconstitution during prolonged treatment of acute and early HIV-1 infection.

BACKGROUND: During acute and early HIV-1 infection (AEI), up to 60% of CD4(+) T cells in the lamina propria of the lower gastrointestinal (GI) tract are lost as early as 2-4 wk after infection. Reconstitution in the peripheral blood during therapy with highly active antiretroviral therapy (HAART) is well established. However, the extent of immune reconstitution in the GI tract is unknown. METHODS AND FINDINGS: Fifty-four AEI patients and 18 uninfected control participants underwent colonic biopsy. Forty of the 54 AEI patients were followed after initiation of antiretroviral therapy (18 were studied longitudinally with sequential biopsies over a 3-y period after beginning HAART, and 22 were studied cross sectionally after 1-7 y of uninterrupted therapy). Lymphocyte subsets, markers of immune activation and memory in the peripheral blood and GI tract were determined by flow cytometry and immunohistochemistry. In situ hybridization was performed in order to identify persistent HIV-1 RNA expression. Of the patients studied, 70% maintained, on average, a 50%-60% depletion of lamina propria lymphocytes despite 1-7 y of HAART. Lymphocytes expressing CCR5 and both CCR5 and CXCR4 were persistently and preferentially depleted. Levels of immune activation in the memory cell population, CD45RO+ HLA-DR+, returned to levels seen in the uninfected control participants in the peripheral blood, but were elevated in the GI tract of patients with persistent CD4+ T cell depletion despite therapy. Rare HIV-1 RNA-expressing cells were detected by in situ hybridization. CONCLUSIONS: Apparently suppressive treatment with HAART during acute and early infection does not lead to complete immune reconstitution in the GI mucosa in the majority of patients studied, despite immune reconstitution in the peripheral blood. Though the mechanism remains obscure, the data suggest that there is either viral or immune-mediated accelerated T cell destruction or, possibly, alterations in T cell homing to the GI tract. Although clinically silent over the short term, the long-term consequences of the persistence of this lesion may emerge as the HIV-1-infected population survives longer owing to the benefits of HAART.

HIV-induced immunosuppression is associated with colonization of the proximal gut by environmental bacteria.

OBJECTIVES: To evaluate the impact of HIV infection on colonization resistance in the proximal gut. DESIGN: It was a case-control study. METHODS: We contrasted microbiota composition between eight HIV-1-infected patients and eight HIV-negative controls to characterize community alteration and detect exogenous bacteria in the esophagus, stomach, and duodenum, as well as the mouth using a universal 16s ribosomal RNA gene survey and correlated the findings with HIV serostatus and peripheral blood T-cell counts. RESULTS: HIV infection was associated with an enrichment of Proteobacteria (P=0.020) and depletion of Firmicutes (P = 0.005) in the proximal gut. In particular, environmental species Burkholderia fungorum and Bradyrhizobium pachyrhizi colonized the duodenum of HIV patients who had abnormal blood CD4 T-cell counts but were absent in HIV-negative controls or HIV patients whose CD4 cell counts were normal. The two species coexisted and exhibited a decreasing trend proximally toward the stomach and esophagus and were virtually absent in the mouth. B. fungorum always outnumbered B. pachyrhizi in a ratio of approximately 15 to 1 regardless of the body sites (P < 0.0001, r = 0.965). Their abundance was inversely correlated with CD4 cell counts (P = 0.004) but not viral load. Overgrowth of potential opportunistic pathogens for example, Prevotella, Fusobacterium, and Ralstonia and depletion of beneficial bacteria, for example, Lactobacillus was also observed in HIV patients. CONCLUSIONS: The colonization of the duodenum by environmental bacteria reflects loss of colonization resistance in HIV infection. Their correlation with CD4 cell counts suggests that compromised immunity could be responsible for the observed invasion by exogenous microbes.

Hepatitis B virus infection: co-infection with hepatitis C virus, hepatitis D virus, and human immunodeficiency virus.

Hepatitis B virus (HBV) shares routes of transmission, namely exchange of infected body fluids, sharing of contaminated needles, and blood transfusion, with other hepatotropic viruses, such as hepatitis C virus (HCV) and hepatitis D virus (HDV) and with systemic retroviral infections, such as the human immunodeficiency virus (HIV). Thus, many HBV infected patients are co-infected with other viral pathogens. Co-infection appears to increase the risk of progression of liver disease and may have important ramifications on choice of antiviral medication and treatment regimen. This article reviews the current knowledge of co-infection of HBV with HCV, HDV, and HIV.

Design aspects of a case-control clinical investigation of the effect of HIV on oral and gastrointestinal soluble innate factors and microbes.

INTRODUCTION: The impaired host defense system in HIV infection impacts the oral and gastrointestinal microbiota and associated opportunistic infections. Antiretroviral treatment is predicted to partially restore host defenses and decrease the oral manifestation of HIV/AIDS. Well-designed longitudinal studies are needed to better understand the interactions of soluble host defense proteins with bacteria and virus in HIV/AIDS. "Crosstalk" was designed as a longitudinal study of host responses along the gastrointestinal (GI) tract and interactions between defense molecules and bacteria in HIV infection and subsequent therapy. PURPOSE: The clinical core formed the infrastructure for the study of the interactions between the proteome, microbiome and innate immune system. The core recruited and retained study subjects, scheduled visits, obtained demographic and medical data, assessed oral health status, collected samples, and guided analysis of the hypotheses. This manuscript presents a well-designed clinical core that may serve as a model for studies that combine clinical and laboratory data. METHODS: Crosstalk was a case-control longitudinal clinical study an initial planned enrollment of 170 subjects. HIV+ antiretroviral naïve subjects were followed for 9 visits over 96 weeks and HIV uninfected subjects for 3 visits over 24 weeks. Clinical prevalence of oral mucosal lesions, dental caries and periodontal disease were assessed. RESULTS: During the study, 116 subjects (47 HIV+, 69 HIV-) were enrolled. Cohorts of HIV+ and HIV- were demographically similar except for a larger proportion of women in the HIV- group. The most prevalent oral mucosal lesions were oral candidiasis and hairy leukoplakia in the HIV+ group. DISCUSSION: The clinical core was essential to enable the links between clinical and laboratory data. The study aims to determine specific differences between oral and GI tissues that account for unique patterns of opportunistic infections and to delineate the differences in their susceptibility to infection by HIV and their responses post-HAART.

Clash of the microbes: let's bring back the good guys.

A 38-year-old man with a history of HIV infection virologically suppressed on antiretroviral therapy presents to his gastroenterologist for evaluation of iron deficiency anemia and weight loss. A diagnostic colonoscopy demonstrates a two-centimeter ulcerated mass in the cecum. Biopsies of the lesion return moderately differentiated adenocarcinoma that is wild type for the KRAS mutation by real-time PCR.

Colorectal cancer screening of high-risk populations: A national survey of physicians.

BACKGROUND: The incidence of colorectal cancer can be decreased by appropriate use of screening modalities. Patients with a family history of colon cancer and of African-American ethnicity are known to be at higher risk of developing colorectal cancer. We aimed to determine if there is a lack of physician knowledge for colorectal cancer screening guidelines based on family history and ethnicity. Between February and April 2009 an anonymous web-based survey was administered to a random sample selected from a national list of 25,000 internists, family physicians and gastroenterologists. A stratified sampling strategy was used to include practitioners from states with high as well as low CRC incidence. All data analyses were performed following data collection in 2009. RESULTS: The average knowledge score was 37 ± 18% among the 512 respondents. Gastroenterologists averaged higher scores compared to internists, and family physicians, p = 0.001. Only 28% of physicians correctly identified the screening initiation point for African-Americans while only 12% of physicians correctly identified the screening initiation point and interval for a patient with a family history of CRC. The most commonly cited barriers to referring high-risk patients for CRC screening were "patient refusal" and "lack of insurance reimbursement." CONCLUSIONS: There is a lack of knowledge amongst physicians of the screening guidelines for high-risk populations, based on family history and ethnicity. Educational programs to improve physician knowledge and to reduce perceived barriers to CRC screening are warranted to address health disparities in colorectal cancer.

TH17, TH22 and Treg cells are enriched in the healthy human cecum.

There is increasing evidence that dysregulation of CD4(+) T cell populations leads to intestinal inflammation, but the regional distribution of these populations throughout the intestinal tract in healthy individuals remains unclear. Here, we show that T(H)17, T(H)22 and T(Reg) cells are enriched in the healthy human cecum compared to the terminal ileum and sigmoid colon, whereas T(H)1 and T(H)2 cells do not significantly vary by location. Transcriptional profiling analysis of paired pinch biopsies from different regions of the intestine identified significant differences in the metabolic state of the terminal ileum, cecum, and sigmoid colon. An increased proportion of T(H)17 cells was positively associated with expression of resistin (RETN) and negatively associated with expression of trefoil factor 1 (TFF1). These results suggest that CD4(+) T helper cells that are important in maintaining mucosal barrier function may be enriched in the cecum as a result of metabolic differences of the surrounding microenvironment.

Design of 16S rRNA gene primers for 454 pyrosequencing of the human foregut microbiome.

AIM: To design and validate broad-range 16S rRNA primers for use in high throughput sequencing to classify bacteria isolated from the human foregut microbiome. METHODS: A foregut microbiome dataset was constructed using 16S rRNA gene sequences obtained from oral, esophageal, and gastric microbiomes produced by Sanger sequencing in previous studies represented by 219 bacterial species. Candidate primers evaluated were from the European rRNA database. To assess the effect of sequence length on accuracy of classification, 16S rRNA genes of various lengths were created by trimming the full length sequences. Sequences spanning various hypervariable regions were selected to simulate the amplicons that would be obtained using possible primer pairs. The sequences were compared with full length 16S rRNA genes for accuracy in taxonomic classification using online software at the Ribosomal Database Project (RDP). The universality of the primer set was evaluated using the RDP 16S rRNA database which is comprised of 433 306 16S rRNA genes, represented by 36 phyla. RESULTS: Truncation to 100 nucleotides (nt) downstream from the position corresponding to base 28 in the Escherichia coli 16S rRNA gene caused misclassification of 87 (39.7%) of the 219 sequences, compared with misclassification of only 29 (13.2%) sequences with truncation to 350 nt. Among 350-nt sequence reads within various regions of the 16S rRNA gene, the reverse read of an amplicon generated using the 343F/798R primers had the least (8.2%) effect on classification. In comparison, truncation to 900 nt mimicking single pass Sanger reads misclassified 5.0% of the 219 sequences. The 343F/798R amplicon accurately assigned 91.8% of the 219 sequences at the species level. Weighted by abundance of the species in the esophageal dataset, the 343F/798R amplicon yielded similar classification accuracy without a significant loss in species coverage (92%). Modification of the 343F/798R primers to 347F/803R increased their universality among foregut species. Assuming that a typical polymerase chain reaction can tolerate 2 mismatches between a primer and a template, the modified 347F and 803R primers should be able to anneal 98% and 99.6% of all 16S rRNA genes in the RDP database. CONCLUSION: 347F/803R is the most suitable pair of primers for classification of foregut 16S rRNA genes but also possess universality suitable for analyses of other complex microbiomes.