Usefulness of Fluoroscopy for Endoscopic Balloon Dilation of Crohn's Disease-Related Strictures.

BACKGROUND: Fluoroscopy is often used for endoscopic balloon dilation (EBD) of Crohn's disease (CD)-related strictures. However, its benefit remains unclear. AIMS: To compare EBD with (EBDF) and without (EBDNF) fluoroscopic guidance in CD patients with strictures. METHODS: Single-center, nested, case-control retrospective study of EBD for CD-related strictures. Technical and clinical success and safety outcomes were compared between EBDF and EBDNF. RESULTS: A total of 122 strictures in 114 CD patients who underwent EBD from 2010 to 2018 at a single institution were reviewed (44 patients EBDF vs. 70 EBDNF). Esophagogastroduodenoscopy was the approach in 8 strictures, colonoscopy in 86, and deep enteroscopy in 28. There were no significant differences in the rates of technical and clinical success, need for repeat dilation and surgery between the two groups, although the mean maximal endoscopic balloon diameter was larger in the EBDNF group (17.1 ± 1.9 vs. 14.1 ± 2.5; p < 0.001). There was one perforation in EBDF and no serious complications in EBDNF. In multivariate analysis, balloon size < 15 mm (odds ratio [OR] 6.388; 95% CI 1.96-20.79; p = 0.002) and multiple strictures (OR 3.897; 95% CI 1.09-14.01; p = 0.037) were associated with repeat EBD, and age < 50 years (OR 7.178; 95% CI 1.38-37.44; p = 0.019) and small bowel (vs. colon) location (OR 7.525; 95% CI 1.51-37.47; p = 0.014) were associated with the need for surgery after EBD. CONCLUSIONS: EBD for CD-related strictures can be performed safely and effectively without fluoroscopic guidance. Balloon size, patient age, stricture location, and multiplicity are associated with clinical success and avoidance of surgery.

Nurse-Administered Propofol Continuous Infusion Sedation for Gastrointestinal Endoscopy in Patients Who Are Difficult to Sedate.

BACKGROUND & AIMS: Patients who chronically use alcohol, marijuana, or opioids, or suffer from post-traumatic stress disorder (PTSD), can be difficult to sedate with midazolam and fentanyl, and often are referred for monitored anesthesia care during endoscopy. Nurse-administered propofol continuous infusion sedation (NAPCIS), which confers the benefit of propofol-based sedation without the added expense of anesthesia, is effective and safe for sedation of healthy patients. We investigated whether NAPCIS also is effective for patients who are difficult to sedate. METHODS: We performed a retrospective study of patients who underwent upper endoscopy or colonoscopy with NAPCIS at a single center from January 2018 through April 2018. We reviewed records from patients who were heavy users of alcohol (n = 105), daily users of marijuana (n = 267) or opioids (n = 178), had a diagnosis of PTSD (n = 91), or were none of these (controls, n = 786). We compared mean fentanyl and propofol doses (adjusted for body weight), procedure and recovery times, procedure success rates, and adverse events. RESULTS: Compared with the controls, the marijuana group required higher mean adjusted sedative doses for colonoscopies (0.6 vs 0.4 mcg/kg fentanyl and 5.0 vs 4.7 mg/kg propofol; P ≤ .025 for both) and upper endoscopies (0.8 vs 0.3 mcg/kg fentanyl and 3.7 vs 3.2 mg/kg propofol; P ≤ .021 for both), the PTSD group required a higher dose of fentanyl for colonoscopies (0.6 vs 0.4 mcg/kg; P = .009), and the alcohol group required a higher dose of fentanyl for upper endoscopies (0.7 vs 0.3 mcg/kg; P < .001). Procedure success rates were high (95.1%-100%) and did not differ significantly between the difficult-to-sedate groups and controls; mean procedure times (7.0-9.0 minutes for upper endoscopies, 21.1-22.9 minutes for colonoscopies) and recovery times (22.5-29.6 minutes) also were similar among groups. Upper endoscopies were associated with lower sedative doses and shorter procedure and recovery times than colonoscopies. Sedation-related adverse events were rare in all groups (only 26 cases total), and there were no serious complications or deaths. CONCLUSIONS: NAPCIS seems to be a safe and effective means of providing sedation for endoscopy to patients who may be difficult to sedate owing to alcohol, marijuana, or opioid use, or PTSD.

Nurse-Administered Propofol Continuous Infusion Sedation: A New Paradigm for Gastrointestinal Procedural Sedation.

INTRODUCTION: Nurse-Administered Propofol Continuous Infusion Sedation (NAPCIS) is a new nonanesthesia propofol delivery method for gastrointestinal endoscopy. NAPCIS is adopted from the computer-assisted propofol sedation (CAPS) protocol. We evaluated the effectiveness, efficiency, and safety of NAPCIS in low-risk subjects. METHODS: Between December 2016 and July 2017, patients who underwent esophagogastroduodenoscopy or colonoscopy with NAPCIS at our center were compared against 2 historical control groups of similar patients who had undergone procedures with CAPS or midazolam and fentanyl (MF) sedation. RESULTS: The mean age of the NAPCIS cohort (N = 3,331) was 55.2 years (45.8% male) for 945 esophagogastroduodenoscopies and 57.8 years (48.7% male) for 2,386 colonoscopies. The procedural success rates with NAPCIS were high (99.1%-99.2%) and similar to those seen in 3,603 CAPS (98.8%-99.0%) and 3,809 MF (99.0%-99.3%) controls. NAPCIS recovery times were shorter than both CAPS and MF (24.8 vs 31.7 and 52.4 minutes, respectively; P < 0.001). On arrival at the recovery unit, 86.6% of NAPCIS subjects were recorded as "Awake" compared with 82.8% of CAPS and 40.8% of MF controls (P < 0.001). Validated clinician and patient satisfaction scores were generally higher for NAPCIS compared with CAPS and MF subjects. For NAPCIS, there were only 4 cases of oxygen desaturation requiring transient mask ventilation and no serious sedation-related complications. These low complication rates were similar to those seen with CAPS (8 cases of mask ventilation) and MF (3 cases). DISCUSSION: NAPCIS seems to be a safe, effective, and efficient means of providing moderate sedation for upper endoscopy and colonoscopy in low-risk patients.

Identification of Candidate Biomarkers Associated with Response to Vedolizumab in Inflammatory Bowel Disease.

BACKGROUND/AIMS: Vedolizumab is an anti-α4ß7 monoclonal antibody approved for the treatment of inflammatory bowel disease (IBD). This exploratory study aimed to identify biomarkers associated with vedolizumab response. METHODS: Twenty-six IBD patients (15 with Crohn's, 11 with ulcerative or indeterminate colitis) initiating vedolizumab at a single center between 2014 and 2016 underwent sampling of serum and peripheral blood mononuclear cells (PBMCs) before and during vedolizumab therapy. Response was defined as steroid-free improvement in endoscopic score or Harvey-Bradshaw index/simple clinical colitis activity index (reduction greater than 3 or total less than 3). PBMCs were evaluated for immunophenotype and expression of α4ß7 integrin on lymphocytes before and during vedolizumab therapy. Serum vedolizumab levels and α4ß7 saturation were measured serially after induction. RESULTS: Fourteen out of 26 (54%) patients treated with vedolizumab responded to therapy. Pretreatment α4ß7 expression was higher in responders on multiple subsets of T, B, and NK cells, with terminal effector memory (p = .0009 for CD4 and .0043 for CD8) and NK cells (p = .0047) best discriminating between responders and nonresponders. During therapy, log10 serum vedolizumab levels at trough were higher in responders than nonresponders (p = .0007). Conversely, the percentage of effector memory T cells with free α4ß7 at trough was lower in responders than nonresponders (p < .0001). However, loss of α4ß7 saturation with vedolizumab was more sensitive to low serum vedolizumab in nonresponders. CONCLUSIONS: Pretreatment α4ß7 expression and α4ß7 receptor saturation during maintenance therapy were identified as candidate biomarkers for vedolizumab response.

Medical Management of Inflammatory Bowel Disease.

The past few decades have seen significant advancements in the medical management of both ulcerative colitis (UC) and Crohn's disease (CD). The previous dependence on steroids is no longer an acceptable strategy following the Food and Drug Administration approval for several new classes of medication. These medications include aminosalicylates, immunomodulators, biologics, and oral targeted small-molecule inhibitors. This article highlights several key trials and discusses modern treatment paradigms for both UC and CD based on disease severity.

Wiskott-Aldrich syndrome protein deficiency in innate immune cells leads to mucosal immune dysregulation and colitis in mice.

BACKGROUND & AIMS: Immunodeficiency and autoimmune sequelae, including colitis, develop in patients and mice deficient in Wiskott-Aldrich syndrome protein (WASP), a hematopoietic cell-specific intracellular signaling molecule that regulates the actin cytoskeleton. Development of colitis in WASP-deficient mice requires lymphocytes; transfer of T cells is sufficient to induce colitis in immunodeficient mice. We investigated the interactions between innate and adaptive immune cells in mucosal regulation during development of T cell-mediated colitis in mice with WASP-deficient cells of the innate immune system. METHODS: Naïve and/or regulatory CD4(+) T cells were transferred from 129 SvEv mice into RAG-2-deficient (RAG-2 KO) mice or mice lacking WASP and RAG-2 (WRDKO). Animals were observed for the development of colitis; effector and regulatory functions of innate immune and T cells were analyzed with in vivo and in vitro assays. RESULTS: Transfer of unfractionated CD4(+) T cells induced severe colitis in WRDKO, but not RAG-2 KO, mice. Naïve wild-type T cells had higher levels of effector activity and regulatory T cells had reduced suppressive function when transferred into WRDKO mice compared with RAG-2 KO mice. Regulatory T-cell proliferation, generation, and maintenance of FoxP3 expression were reduced in WRDKO recipients and associated with reduced numbers of CD103(+) tolerogenic dendritic cells and levels of interleukin-10. Administration of interleukin-10 prevented induction of colitis following transfer of T cells into WRDKO mice. CONCLUSIONS: Defective interactions between WASP-deficient innate immune cells and normal T cells disrupt mucosal regulation, potentially by altering the functions of tolerogenic dendritic cells, production of interleukin-10, and homeostasis of regulatory T cells.

Vedolizumab Efficacy Is Associated With Decreased Intracolonic Dendritic Cells, Not Memory T Cells.

BACKGROUND: Vedolizumab, an antibody blocking integrin α4ß7, is a safe and effective therapy for Crohn's disease and ulcerative colitis. Blocking α4ß7 from binding its cognate addressin MAdCAM-1 on intestinal blood vessel endothelial cells prevents T cells from migrating to the gut mucosa in animal models. However, data supporting this mechanism of action in humans is limited. METHODS: We conducted a cross-sectional case-control study to evaluate the effect of vedolizumab on intestinal immune cell populations while avoiding the confounding effect of resolving inflammation on the cellularity of the colonic mucosa in treatment-responsive patients. Colon biopsies from 65 case subjects receiving vedolizumab were matched with biopsies from 65 control individuals, similar in disease type, medications, anatomic location, and inflammation. Biopsies were analyzed by flow cytometry and full messenger RNA transcriptome sequencing of sorted T cells. RESULTS: No difference was seen between vedolizumab recipients and control individuals in the quantity of any antigen-experienced T lymphocyte subset or in the quality of the transcriptome in any experienced T cell subset. Fewer naïve colonic B and T cells were seen in vedolizumab recipients than control individuals, regardless of response. However, the most striking finding was a marked reduction in CD1c+ (BDCA1+) dendritic cells exclusively in vedolizumab-responsive patients. In blood, these dendritic cells ubiquitously express high levels of α4ß7, which is rapidly downregulated upon vedolizumab exposure. CONCLUSIONS: The clinical effects of vedolizumab reveal integrin α4ß7-dependent dendritic cell migration to the intestinal mucosa to be central to inflammatory bowel disease pathogenesis.

Vedolizumab had no effect on the number or gene expression of memory T lymphocytes in the colons of recipients relative to control individuals. However, the colons of vedolizumab-responsive patients had distinctly fewer dendritic cells, which in blood express the most integrin α4ß7.

Escherichiacoli-Specific CD4+ T Cells Have Public T-Cell Receptors and Low Interleukin 10 Production in Crohn's Disease.

BACKGROUND & AIMS: Crohn's disease (CD) likely represents decreased immune tolerance to intestinal bacterial antigens. Most CD patients have high titers of antibodies to intestinal commensal proteins, including the outer membrane porin C (OmpC) of Escherichia coli. METHODS: By using major histocompatibility complex II tetramers, we identified an HLA-DRB1∗15:01-restricted peptide epitope of OmpC recognized by CD4+ T cells in peripheral blood mononuclear cells from HLA-DRB1∗15:01+ healthy control (HC) and CD patients. RESULTS: The precursor frequency of these cells in CD correlated with anti-OmpC IgA titers, but did not differ from that of HCs. In both cohorts, they showed a CD161+, integrin α4ß7+ phenotype ex vivo by flow cytometry, distinct from the C-X-C Motif Chemokine Receptor 3 phenotype of autologous influenza hemagglutinin (Flu) peptide-specific T cells. The T-cell receptor α and ß chains of in vitro-expanded OmpC-specific T-cell clones often contained public amino acid sequences that were identical in cells from different patients. Expanded T-cell clones from CD subjects produced significantly less interleukin (IL)10 (P < .0001) than those from HCs, and a trend toward decreased production of the T helper 2 cell-associated IL4, IL5, and IL13 by CD clones also was seen. CONCLUSIONS: Both HCs and CD patients have detectable OmpC-specific T cells in circulation, with similar immunophenotypes and often identical T-cell-receptor sequences. However, expanded clones from patients with CD produce less of the immunoregulatory cytokine IL10, showing a selective defect in the regulatory function of intestinal microbial antigen-specific T cells in patients with CD.

Immunologic Alterations Associated With Oral Delivery of Anti-CD3 (OKT3) Monoclonal Antibodies in Patients With Moderate-to-Severe Ulcerative Colitis.

AIM: The aim of this study was to determine the immunologic effects and safety of oral anti-CD3 in patients with ulcerative colitis (UC). METHODS: An open-label pilot study of orally delivered anti-CD3 was performed in patients with moderate-to-severe UC. The primary end points were changes in immunologic parameters and evaluation for safety. RESULTS: Six subjects received oral OKT3. Biologic effects of oral anti-CD3 included significantly increased proliferation in response to anti-CD3 and anti-inflammatory gene expression profile in peripheral blood mononuclear cells. No serious treatment-related adverse events occurred. CONCLUSION: Orally delivered anti-CD3 resulted in immunologic changes in patients with UC.

Regulatory T cells in inflammatory bowel disease.

PURPOSE OF REVIEW: The intestinal immune system must orchestrate a complex balance between proinflammatory and anti-inflammatory responses to luminal antigens, and disruptions in this balance can result in inflammatory bowel disease (IBD). This review explores recent data that elucidate the role of regulatory T cells (Tregs) in the pathogenesis of IBD in mice and humans. RECENT FINDINGS: Data from murine models of colitis implicate several novel mechanisms critical to Treg function and generation including the inhibitory cytokine interleukin-35, pericellular adenosine generation and cytokine deprivation-induced apoptosis. Although Tregs are essential in mice for the maintenance of intestinal homeostasis, their role in human IBD remains unclear. Patients with IBD appear to have relatively reduced numbers of Tregs in the blood and colon; however, Tregs from these patients are functional in vitro. SUMMARY: Tregs are important for the maintenance of intestinal self-tolerance and will likely prove to be an important avenue for therapeutic manipulation in IBD.

The role of CD28 and CTLA4 in the function and homeostasis of CD4+CD25+ regulatory T cells.

CD4+CD25+ T cells regulate a variety of autoimmune and alloimmune responses including the development of autoimmune diabetes in non-obese diabetic (NOD) mice. We have examined the role of CD28/CTLA4/B7 interactions in the expansion and survival of CD4+CD25+ regulatory T cells (T(reg)) in this setting. CD28/ B7 interactions are essential in the development of T(reg) in the thymus and for their survival in the periphery. The CD28-mediated homeostasis of these cells is independent of Il2, OX40, CD40L, and survival factor Bcl-XI. In addition, analysis of T(reg) from CTLA4-deficient mice suggests that CTLA4 expression is not required for their development or function. However, non-activating anti-CTLA4 antibodies blocked the suppressor activity of regulatory cells in vitro. Thus, clinical application of co-stimulatory blockade using agents such as CTLA4Ig in the treatment of autoimmune disease may result in complicated outcomes.

Distinct roles of CTLA-4 and TGF-beta in CD4+CD25+ regulatory T cell function.

Both CTLA-4 and TGF-beta have been implicated in suppression by CD4+CD25+ regulatory T cells (Treg). In this study, the relationship between CTLA-4 and TGF-beta in Treg function was examined. Blocking CTLA-4 on wild-type Treg abrogated their suppressive activity in vitro, whereas neutralizing TGF-beta had no effect, supporting a TGF-beta-independent role for CTLA-4 in Treg-mediated suppression in vitro. In CTLA-4-deficient mice, Treg development and homeostasis was normal. Moreover, Treg from CTLA-4-deficient mice exhibited uncompromised suppressive activity in vitro. These CTLA-4-deficient Treg expressed increased levels of the suppressive cytokines IL-10 and TGF-beta, and in vitro suppression mediated by CTLA-4(-/-) Treg was markedly reduced by neutralizing TGF-beta, suggesting that CTLA-4-deficient Treg develop a compensatory suppressive mechanism through CTLA-4-independent production of TGF-beta. Together, these data suggest that CTLA-4 regulates Treg function by two distinct mechanisms, one during functional development of Treg and the other during the effector phase, when the CTLA-4 signaling pathway is required for suppression. These results help explain contradictions in the literature and support the existence of functionally distinct Treg.

Cutting edge: CD28 controls peripheral homeostasis of CD4+CD25+ regulatory T cells.

CD28/B7 blockade leads to exacerbated autoimmune disease in the nonobese diabetic mouse strain as a result of a marked reduction in the number of CD4(+)CD25(+) regulatory T cells (Tregs). Herein, we demonstrate that CD28 controls both thymic development and peripheral homeostasis of Tregs. CD28 maintains a stable pool of peripheral Tregs by both supporting their survival and promoting their self-renewal. CD28 engagement promotes survival by regulating IL-2 production by conventional T cells and CD25 expression on Tregs.