Gluten induces rapid reprogramming of natural memory αβ 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+ αβ and γδ T-IELs. Natural CD8+ αβ 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 αβ 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.

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.

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.

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.