Gluten induces rapid reprogramming of natural memory αß and γδ intraepithelial T cells to induce cytotoxicity in celiac disease.

Celiac disease (CD) is an autoimmune disease in which intestinal inflammation is induced by dietary gluten. The means through which gluten-specific CD4+ T cell activation culminates in intraepithelial T cell (T-IEL)-mediated intestinal damage remain unclear. Here, we performed multiplexed single-cell analysis of intestinal and gluten-induced peripheral blood T cells from patients in different CD states and healthy controls. Untreated, active, and potential CD were associated with an enrichment of activated intestinal T cell populations, including CD4+ follicular T helper (TFH) cells, regulatory T cells (Tregs), and natural CD8+ αß and γδ T-IELs. Natural CD8+ αß and γδ T-IELs expressing activating natural killer cell receptors (NKRs) exhibited a distinct TCR repertoire in CD and persisted in patients on a gluten-free diet without intestinal inflammation. Our data further show that NKR-expressing cytotoxic cells, which appear to mediate intestinal damage in CD, arise from a distinct NKR-expressing memory population of T-IELs. After gluten ingestion, both αß and γδ T cell clones from this memory population of T-IELs circulated systemically along with gluten-specific CD4+ T cells and assumed a cytotoxic and activating NKR-expressing phenotype. Collectively, these findings suggest that cytotoxic T cells in CD are rapidly mobilized in parallel with gluten-specific CD4+ T cells after gluten ingestion.

Doxycycline-induced cholestatic liver injury.

Doxycycline-induced liver injury is a rare phenomenon, with an unclear clinical course and etiopathogenesis. The onset of injury may be acute-to-subacute, with a pattern ranging from hepatocellular or cholestatic to mixed, and it often lasts up to several weeks. We present a case of cholestatic liver injury secondary to doxycycline use in a middle-aged woman. In patients with a history of doxycycline exposure and subsequent hepatic injury, an adverse drug reaction due to doxycycline should remain on the differential, and immediate removal of the offending agent with close monitoring of the clinical condition should be pursued.

Characteristics and Outcomes of Patients Undergoing Endoscopy During the COVID-19 Pandemic: A Multicenter Study from New York City.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic has significantly impacted the practice of endoscopy, but characteristics of COVID patients undergoing endoscopy have not been adequately described. AIMS: To compare findings, clinical outcomes, and patient characteristics of endoscopies performed during the pandemic in patients with and without COVID-19. METHODS: This was a retrospective multicenter study of adult endoscopies at six academic hospitals in New York between March 16 and April 30, 2020. Patient and procedure characteristics including age, sex, indication, findings, interventions, and outcomes were compared in patients testing positive, negative, or untested for COVID-19. RESULTS: Six hundred and five endoscopies were performed on 545 patients during the study period. There were 84 (13.9%), 255 (42.2%), and 266 (44.0%) procedures on COVID-positive, negative, and untested patients, respectively. COVID patients were more likely to undergo endoscopy for gastrointestinal bleeding or gastrostomy tube placement, and COVID patients with gastrointestinal bleeding more often required hemostatic interventions on multivariable logistic regression. COVID patients had increased length of stay, intensive care unit admission, and intubation rate. Twenty-seven of 521 patients (5.2%) with no or negative COVID testing prior to endoscopy later tested positive, a median of 13.5 days post-procedure. CONCLUSIONS: Endoscopies in COVID patients were more likely to require interventions, due either to more severe illness or a higher threshold to perform endoscopy. A significant number of patients endoscoped without testing were subsequently found to be COVID-positive. Gastroenterologists in areas affected by the pandemic must adapt to changing patterns of endoscopy practice and ensure pre-endoscopy COVID testing.

Anesthesia Assistance in Screening Colonoscopy and Adenoma Detection Rate Among Trainees.

BACKGROUND AND AIMS: The use of anesthesia assistance (AA) for screening colonoscopy has been increasing substantially over the past decade, raising concerns about procedure safety and cost without demonstrating a proven improvement in overall quality indicators such as adenoma detection rate (ADR). The effect of AA on ADR has not been extensively studied among trainees learning colonoscopy. We aimed to determine whether type of sedation used during screening colonoscopy affects trainee ADR. METHODS: Using the electronic endoscopy databases of two hospitals in our medical center, we identified colonoscopies performed by 15 trainees from 2014 through 2018, including all screening examinations in which the cecum was reached. Multivariable logistic regression was used to determine factors associated with adenoma detection. RESULTS: We identified 1420 unique patients who underwent screening colonoscopy by a trainee meeting the inclusion criteria. Of these, 459 (32.3%) were performed with AA. Overall trainee ADR was 39.6%, with ADR increasing from 35.0% in year one of training to 42.8% in year three (p = 0.047). ADR for cases with AA was 37.9%, while ADR for conscious sedation cases was 32.0% (p = 0.374). Despite this 5.9% absolute difference, the use of AA was not associated with finding an adenoma on multivariable analysis when controlling for patient age, sex, smoking status, body mass index, trainee year of training, mean withdrawal time, supervising attending ADR, and bowel preparation quality (OR 0.85; 95% CI 0.67-1.09). CONCLUSIONS: Despite providing the ability to more consistently sedate patients, the use of AA did not affect trainee ADR. These results on trainee ADR and sedation type suggest that the overall lack of association between AA use and ADR is applicable to the trainee setting.

Endoscopic Algorithm for Management of Gastrointestinal Bleeding in Patients With Continuous Flow LVADs: A Prospective Validation Study.

BACKGROUND: Gastrointestinal bleeding (GIB) is a common complication of left ventricular assist device (LVAD) therapy accounting for frequent hospitalizations and high resource utilization. METHODS: We previously developed an endoscopic algorithm emphasizing upfront evaluation of the small bowel and minimizing low-yield procedures in LVAD recipients with GIB. We compared the diagnostic and therapeutic yield of endoscopy, health-care costs, and re-bleeding rates between conventional GIB management and our algorithm using chi-square, Fisher's exact test, Wilcoxon-Mann-Whitney, and Kaplan-Meier analysis. RESULTS: We identified 33 LVAD patients with GIB. Presentation was consistent with upper GIB in 20 (61%), lower GIB in 5 (15%), and occult GIB in 8 (24%) patients. Forty-one endoscopies localized a source in 23 (56%), resulting in 14 (34%) interventions. Algorithm implementation compared with our conventional cohort was associated with a 68% increase in endoscopic diagnostic yield (P< .01), a 113% increase in therapeutic yield (P= .01), a 27% reduction in the number of procedures per patient (P < .01), a 33% decrease in length of stay (P < .01), and an 18% reduction in estimated costs (P < .01). The same median number of red blood cell transfusions were used in the 2 cohorts, with no increase in re-bleeding events in the algorithm cohort (33.3%) compared with our conventional cohort (43.7%). CONCLUSIONS: Our endoscopic management algorithm for GIB in LVAD patients proved effective in reducing low-yield procedures, improving the diagnostic and therapeutic yield of endoscopy, and decreasing health-care resource utilization and costs, while not increasing the risk of a re-bleeding event.

Trainee colonoscopy quality is influenced by the independent and unobserved performance characteristics of supervising physicians.

Background Endoscopy training remains an apprenticeship, and the characteristics that facilitate transfer of high quality procedural skills from role models to trainees are unknown. We sought to determine whether unobserved supervisor performance influences the quality of colonoscopy performed by trainees, by studying how supervisors perform alone and how trainees perform while under those same supervisors. Methods This was a retrospective cross-sectional study conducted among ambulatory adults ≥ 50 years old who underwent colonoscopy for cancer screening or polyp surveillance from 2006 to 2015 at one academic medical center. The primary exposures were the colonoscopy withdrawal time (WT) and adenoma detection rate (ADR) of supervisors while performing colonoscopies alone. The primary outcomes were the WT and ADR of trainees performing colonoscopies under supervision. Results Data were included from 22 attending gastroenterologist supervisors, 56 gastroenterology fellow trainees, and 2777 adults undergoing 3094 colonoscopy procedures. Among all supervised colonoscopies, mean trainee WT was 12.7 minutes (SD 4.9) and trainee ADR was 33.5 %. The trainee WT was 0.42 minutes longer (standard error = 0.16, P  = 0.01) per minute increase in supervisor WT. Similarly, trainee ADR was higher under a high ADR supervisor, and the odds ratio of high compared to low supervisor ADR category was 1.28 (95 %CI 1.01 - 1.62, P  = 0.04) after adjusting for other factors. Conclusions The unobserved performance characteristics of supervising endoscopists may influence the quality of colonoscopy performed by trainees.

Limited usefulness of endoscopic evaluation in patients with continuous-flow left ventricular assist devices and gastrointestinal bleeding.

BACKGROUND: Gastrointestinal bleeding (GIB) is a frequent cause of re-admission in patients with continuous-flow left ventricular assist devices (CF-LVADs) and is associated with multiple endoscopic procedures and high resource utilization. Our aim was to determine the diagnostic and therapeutic yield of endoscopy and to develop a more cost-effective approach for the management of GIB in CF-LVAD recipients. METHODS: We retrospectively reviewed 428 patients implanted with a CF-LVAD between 2009 and 2016 at the Columbia University Medical Center and identified those hospitalized for GIB. Patients were categorized into upper GIB (UGIB), lower GIB (LGIB) and occult GIB (OGIB), based on clinical presentation. RESULTS: Eighty-seven CF-LVAD patients underwent a total of 164 GIBs, resulting in 239 endoscopies. Index presentation was consistent with UGIB in 30 (34.5%), LGIB in 19 (21.8%) and OGIB in 38 (43.7%) patients. On the first GIB, 147 endoscopies localized a bleeding source in 49 (30%), resulting in 24 (16.3%) endoscopic interventions. Of 45 lesions identified, arteriovenous malformations (AVMs) were the most common (22, 48.9%). A gastric or small bowel source (HR 2.8, p = 0.003) and an endoscopic intervention (HR 1.9, p = 0.04) predicted recurrent GIB. The proposed algorithm may reduce the number of endoscopic procedures by 45% and costs by 35%. CONCLUSIONS: Occult GIB is the most common presentation in CF-LVAD patients and carries the lowest diagnostic and therapeutic yield of endoscopy. Performing an intervention was among the strongest predictors of recurrent GIB. Our proposed algorithm may decrease the number of low-yield procedures and improve resource utilization.

Incidence and risk factors for gastrointestinal bleeding among patients admitted to medical intensive care units.

OBJECTIVES: To identify incidence and risk factors for new-onset gastrointestinal bleeding (GIB) in a medical intensive care unit (ICU), a topic for which there is a paucity of recent studies. DESIGN: Retrospective cohort study. SETTING: Medical ICUs at our tertiary-care hospital, from 2007 to 2013. PATIENTS: Patients who developed clinically significant GIB after entering the ICU. INTERVENTIONS: Univariable and multivariable analyses. MAIN OUTCOME MEASURES: Incidence and risk factors for development of GIB. RESULTS: 4439 patients entered the medical ICU without a pre-existing GIB and 58 (1.3%) developed GIB while in the ICU. Risk factors included length of ICU stay (OR per additional day 1. 06; 95% CI 1.04 to 1.09) and elevated creatinine on ICU admission (OR 2.35; 95% CI 1.18 to 4.68, p=0.02). Elevated bilirubin on ICU admission (OR 2.08; 95% CI 0.97 to 4.47, p=0.06), and elevated aspartate transaminase (AST) on ICU admission (OR 2.20; 95% CI 0.96 to 5.03, p=0.06) trended towards increased risk of GIB that did not meet statistical significance. Age, gender, admission coagulation studies and mechanical ventilation were not predictive of GIB. Among those patients with new-onset GIB in the ICU, 47% died during that hospitalisation, as compared with those 30% of those without a GIB, p<0.01. CONCLUSIONS: Onset of GIB is now an infrequent occurrence in the ICU setting; however those with elevated bilirubin, AST and creatinine upon admission, and with longer length of ICU stay appear at increased risk and may benefit from closer monitoring.

Low adherence to national guidelines for proton-pump inhibitor prescription in patients receiving combination aspirin and anticoagulation.

BACKGROUND: Aspirin, when used with concurrent anticoagulation, increases the risk of gastrointestinal bleeding (GIB). Therefore, multisociety guidelines recommend prophylactic proton-pump inhibitors (PPIs) for patients receiving aspirin and anticoagulation. We aimed to determine rates and predictors of adherence to these recommendations. METHODS: All adult inpatients discharged from the hospital on aspirin and anticoagulation from July 2009 to June 2014 were retrospectively evaluated for PPI prescription on discharge instructions. We used univariate and multivariate logistic regression to test for predictors of PPI prescription. RESULTS: A total of 2422 patients were discharged on aspirin and anticoagulation; the mean age was 68 years and 53.2% were male; 42.2% were prescribed a PPI at discharge. On univariate analysis, factors associated with discharge PPI prescription included increased age (47.1% versus 37.9%), white race (47.3% versus 37.1-40.2%), higher aspirin dose (55.1% versus 39.4%), being married (46.2% versus 39.4%) and preadmission PPI use (96.6% versus 23.4%). On multivariate analysis, significant predictors of discharge PPI prescription were age 60-69 years [odds ratio (OR) 1.61] and 70-79 years (OR 1.48), and preadmission PPI use (OR 120.03). Lower odds of discharge PPI prescription included Medicaid (OR 0.55) or Medicare (OR 0.71) insurance, Spanish language (OR 0.63), and lower dose aspirin (81 mg) (OR 0.40). CONCLUSIONS: A total of 42.2% of patients discharged on aspirin and anticoagulation were prescribed PPIs. Older age and preadmission PPI use were predictive of PPI prescription, while Medicaid/Medicare insurance, Spanish language, and lower dose aspirin decreased the likelihood of discharge PPI prescription. This creates an opportunity to improve primary GIB prevention through quality improvement interventions.

Interferon-alpha-2b and ribavirin for retreatment of chronic hepatitis C.

BACKGROUND/AIMS: Subjects with chronic hepatitis C who fail treatment with interferon-alpha are generally divided into two groups: "relapsers" who normalized serum aminotransferase activity and have undetectable viral RNA during treatment and "non-responders" who do not achieve these results. The aim of this study was to examine retreatment of such subjects. METHODOLOGY: We studied 117 subjects with chronic hepatitis C who failed treatment with interferon-alpha, 87 of whom were "non-responders" and 30 "relapsers." Retreatment was with either interferon-alpha-2b plus ribavirin for 48 weeks or with interferon-alpha-2b plus placebo for 24 weeks followed by 24 weeks of combined therapy. RESULTS: Sustained response rates, defined as undetectable viral RNA in serum 6 months after retreatment, were 53% in "relapsers" and 10% in "non-responders" (P < 0.005). There was no significant difference if ribavirin was given for 24 or 48 weeks. In "non-responders" infected with genotypes other than type 1, 42% achieved a sustained response compared to 5% infected with genotype 1 (P = 0.027; odds ratio 7.09). CONCLUSIONS: Treatment with interferon-alpha-2b plus ribavirin is effective in approximately 50% of "relapsers" and "non-responders" infected with non-type 1 genotypes of hepatitis C virus. This therapy is only marginally effective in "non-responders" infected with genotype 1a or 1b.