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Autologous hematopoietic stem cell transplantation (HSCT) and mesenchymal stromal cell therapy have been proposed for patients with refractory Crohn's disease (CD) and fistulizing CD, respectively. Will these highly advanced techniques be available only for select patients, at specialized centers, or is further clinical development justified, with the aim of offering widespread, more definitive therapeutic options for often very difficult to treat disease? Patients with CD who are eligible for HSCT have typically been failed by most approved therapies, have undergone multiple surgeries, and have coped with years of disease activity and poor quality of life. The objective of HSCT is to immediately shut down the immune response and allow the transplanted stem cells to develop into self-tolerant lymphocytes. For patients with fistulizing CD, mesenchymal stromal cell therapy deposits MSCs locally, into fistulizing tracts, to down-regulate the local immune response and induce wound healing. Recent trials have produced promising results for HSCT and mesenchymal stromal cell therapy as alternatives to systemic therapies and antibiotics for patients with inflammatory bowel diseases, but are these immunotherapies ready for prime time?, (Copyright © 2017 AGA Institute. Published by Elsevier Inc. All rights reserved.)

Background & Aims: Selective cyclooxygenase-2 inhibitors were developed to reduce the gastrointestinal risk associated with nonsteroidal anti-inflammatory drugs (NSAIDs). The Therapeutic Arthritis Research and Gastrointestinal Event Trial was the largest study to evaluate primarily the gastrointestinal safety outcomes of selective cyclooxygenase-2 inhibitors. Data from the Therapeutic Arthritis Research and Gastrointestinal Event Trial were used to identify risk factors and investigate the safety of lumiracoxib in subgroups., Methods: Patients with osteoarthritis (age, >or=50 y) were randomized to receive lumiracoxib 400 mg once daily, naproxen 500 mg twice daily, or ibuprofen 800 mg 3 times daily for 12 months. Events were categorized by a blinded adjudication committee. The primary end point was all definite or probable ulcer complications., Results: For patients taking NSAIDs, factors associated with an increased risk of ulcer complications were age 65 years or older (hazard ratio [HR], 2.30; 95% confidence interval [CI], 1.48-3.59), previous history of gastrointestinal bleed or ulcer (HR, 3.61; 95% CI, 1.86-7.00), non-Caucasian racial origin (HR, 2.10; 95% CI, 1.35-3.27), and male sex (HR, 1.70; 95% CI, 1.08-2.68). With lumiracoxib, significant risk factors were age 65 years or older (HR, 3.18; 95% CI, 1.40-7.20), male sex (HR, 2.60; 95% CI, 1.25-5.40), non-Caucasian racial origin (HR, 2.16; 95% CI, 1.02-4.59), and concomitant aspirin use (HR, 2.89; 95% CI, 1.40-5.97). Increased risks in patients age 65 years and older were increased further if other risk factors were present. Lumiracoxib maintained an advantage over NSAIDs across all subgroups except aspirin use., Conclusions: Lumiracoxib was associated with a reduced risk of ulcer complications compared with NSAIDs in all significant subgroups except aspirin users.

Background & Aims: Epidemiologic studies suggest nonsteroidal anti-inflammatory drugs (NSAIDs) increase the risk for lower gastrointestinal (GI) clinical events, but data from prospective trials are lacking. Cyclooxygenase (COX)-2-selective inhibitors decrease upper GI clinical events but the effect on lower GI events has not been determined. We performed a post hoc analysis of serious lower GI clinical events with a nonselective NSAID and a COX-2-selective agent in a prospective, double-blind, randomized GI outcomes trial., Methods: A total of 8076 rheumatoid arthritis patients 50 years or older (or 40 years or older on corticosteroid therapy) expected to require NSAIDs for 1 year or greater were randomly assigned to naproxen 500 mg twice daily or rofecoxib 50 mg daily. The rate of serious lower GI clinical events, defined as bleeding with a 2 g/dL drop in hemoglobin or hospitalization, or hospitalization for perforation, obstruction, ulceration, or diverticulitis, was determined., Results: The rate of serious lower GI events per 100 patient-years was 0.41 for rofecoxib and 0.89 for naproxen (relative risk, 0.46; 95% confidence interval [CI], 0.22-0.93; P = 0.032). Serious lower GI events accounted for 39.4% of all serious GI events (complicated upper GI event or lower GI event) among patients taking naproxen and 42.7% among those taking rofecoxib., Conclusions: Serious lower GI events occurred at a rate of 0.9% per year in rheumatoid arthritis patients taking the nonselective NSAID naproxen, accounting for nearly 40% of the serious GI events that developed in these patients. Serious lower GI events were 54% lower with the use of the selective COX-2 inhibitor rofecoxib.

Background & Aims: Epidemiologic data indicate that the risk of nonsteroidal anti-inflammatory drug (NSAID)-related gastrointestinal (GI) clinical events varies based on patients' clinical characteristics. The authors determined risk factors for NSAID-related clinical upper GI events and the event rates, absolute risk reductions, and numbers needed to treat for individual risk factors for a nonselective NSAID and a selective cyclooxygenase 2 inhibitor in a double-blind outcomes trial., Methods: Eight thousand seventy-six rheumatoid arthritis patients aged >or=50 years (or >or=40 on corticosteroid therapy) were randomly assigned to rofecoxib 50 mg daily or naproxen 500 mg twice daily for a median of 9 months. The development of clinical upper GI events (bleeding, perforation, obstruction, and symptomatic ulcer identified on clinically indicated work-up) was assessed., Results: Significant risk factors included prior upper GI events, age >or=65, and severe rheumatoid arthritis (RR, 2.3-3.9). Patients administered naproxen who had prior upper GI complications or who were aged >or=75 years had 18.84 or 14.46 events per 100 patient-years, and the risk of events remained constant over time. The reduction in events with rofecoxib was similar in high- and low-risk subgroups (RR, 0.31-0.68). The number needed to treat with rofecoxib instead of naproxen to avert 1 GI event was 10-12 in highest risk patients (prior event, age >or=75 years, or severe rheumatoid arthritis), 17-33 in patients with other risk factors, and 42-106 in low-risk patients., Conclusions: NSAID-related GI events increase dramatically with risk factors such as prior events or older age. Ten to twelve high-risk patients need to be treated with a protective strategy such as the selective cyclooxygenase 2 inhibitor, rofecoxib, to avert a clinical GI event.

Background & Aims: Rofecoxib, an inhibitor of the inducible cyclooxygenase (COX)-2 enzyme, appears not to cause acute gastroduodenal injury or chronic ulceration. To attribute this to COX-2 selectivity with sparing of gastric mucosal prostaglandin synthesis requires direct proof., Methods: Twenty-four healthy, nonsmoking Helicobacter pylori-negative volunteers were randomized to 1 of 2 separate concurrent blinded crossover studies. Sixteen volunteers received rofecoxib, 50 mg once daily, for 5 days in one treatment period and placebo in the other. Eight volunteers similarly received naproxen, 500 mg twice daily, and placebo. On day 5 of each period, antral mucosal prostaglandin E2 (PGE2) synthesis was measured by radioimmunoassay after vortexing for 3 minutes. Whole blood COX-1 activity was measured as serum thromboxane (TXB)2- and COX-2 activity as lipopolysaccharide (LPS)-induced PGE2., Results: Naproxen decreased gastric mucosal PGE2 synthesis by 65% (90% confidence interval [CI], 53%-74%; P = 0.001 vs. placebo) in contrast to an 18% increase after rofecoxib (90% CI, -11% to 57%; P = 0.313 vs. placebo). Naproxen also significantly inhibited both serum TXB2 by 94% and LPS-induced PGE2 production by 77% (both P < or = 0.002 vs. placebo), but rofecoxib only inhibited COX-2-dependent LPS-induced PGE(2) (by 79%; P < 0.001 vs. placebo)., Conclusions: Rofecoxib (50 mg) lacked naproxen's ability to reduce the availability of gastroprotective prostaglandins.

By inhibiting prostaglandin synthesis, nonsteroidal anti-inflammatory drugs (NSAIDs) compromise gastroduodenal defense mechanism including blood flow and mucus/bicarbonate secretion. This has led to NSAIDs being the most widely reported drug cause of adverse events. While NSAIDs also cause dyspepsia, inhibition of prostaglandin synthesis may reduce this from even higher levels that would otherwise prevail and mask ulcer-related dyspepsia, making anticipatory management difficult. On average, the risk of ulcer complications increases 4-fold, resulting in 1.25 additional hospitalizations per 100 patient-years according to one estimate. Older patients, those with a past history, and those taking anticoagulants or corticosteroids are at higher risk. Risk is dose dependent and is lower with ibuprofen at low doses than with other NSAIDs. It is unlikely that Helicobacter pylori increases the risk, and under some circumstances it may be protective. Selective inhibitors of the inducible cyclooxygenase 2 spare gastric mucosal prostaglandin synthesis and do not damage the gastric mucosa. Their place in therapy, compared with use of misoprostol or proton pump inhibitors, is currently emerging. Future competitors may include nitric oxide-donating, zwitterionic, or R-enantiomer NSAIDs.

Background & Aims: Gastric injury by nonsteroidal anti-inflammatory drugs (NSAIDs) is minimal in neutropenic animals. This study examined peptic ulcer development in the presence or absence of gastric neutrophils in patients requiring long-term use of NSAIDs., Methods: Gastric histology, neutrophils, and Helicobacter pylori were assessed in 120 patients randomized to receive placebo or 20 or 40 mg famotidine twice daily as prophylaxis against NSAID-related ulcers and who underwent endoscopy at 0, 4, 12, and 24 weeks., Results: In 43 patients without gastric neutrophils, ulcers developed in 1 of 14 (7.7%) taking placebo, 2 of 16 (12.5%) taking 20 mg famotidine, and none of 13 taking 40 mg famotidine. However, in 77 patients with neutrophils, ulcers developed in 13 of 28 (47. 4%) taking placebo (P < 0.001), 3 of 26 (12.6%) taking 20 mg famotidine, and 3 of 23 (13%) taking 40 mg famotidine. Eight of 46 patients (17%) without H. pylori had neutrophils compared with 69 of 74 (93%) with both H. pylori and neutrophils (P < 0.001)., Conclusions: Gastric neutrophils increase the incidence of ulceration in long-term NSAID users. Because neutrophils exist with H. pylori, eradicating this infection might prevent NSAID-related peptic ulcers.

Background & Aims: Platelet-activating factor (PAF) is increased during relapse of ulcerative colitis. In animal models of experimental colitis, specific inhibition of PAF has reduced inflammation. The aim of this study was to evaluate the efficacy and safety of the PAF antagonist SR27417A in moderately active UC., Methods: A double-blind multicenter trial was conducted during a 28-day period in hospital outpatients with an exacerbation of ulcerative colitis. Patients were randomized to receive 10 mg/day SR27417A or placebo, and both groups were also given 2.4 g mesalazine. Patient classification at the end of the treatment period was based on sigmoidoscopy and clinical scores., Results: One hundred fifty-one subjects entered the study (75 placebo and 76 SR27417A). The remission rate between placebo- and SR27417A-treated patients at 28 days was not significantly different (29.0% and 35.6% respectively; P = 0.44). Similarly, 49.2% treated with SR27417A had a definite or possible improvement of their symptom score compared with 48.3% of those treated with placebo (P = 0.43). Four subjects in the placebo group and 5 subjects in the SR27417A group discontinued the drug treatment because of adverse events. No significant adverse events were thought to be caused by SR27417A., Conclusions: Although the specific PAF antagonist SR27417A is safe in humans, there is no evidence of efficacy in the treatment of acute ulcerative colitis.

Background & Aims: Nonsteroidal anti-inflammatory drugs (NSAIDs) are strongly associated with gastroduodenal ulceration. How to manage patients with NSAID-associated ulcers is a common clinical dilemma. High-dose famotidine in the healing and maintenance of NSAID-associated gastroduodenal ulceration was therefore evaluated., Methods: One hundred four patients with rheumatoid or osteoarthritis who had gastroduodenal ulceration received famotidine, 40 mg twice daily. Sixteen patients stopped and 88 continued their NSAID treatment. Ulcer healing was assessed endoscopically at 4 and 12 weeks. Seventy-eight NSAID users with healed ulcers were then randomized to receive 40 mg twice daily famotidine or placebo and underwent endoscopy at 4, 12, and 24 weeks., Results: Cumulative ulcer healing rates at 12 weeks were 89.0% (95% confidence interval [CI], 82.3%-95.7%) for patients who continued NSAID treatment and 100% (95% CI, 82.9%-100.0%) for those who stopped. The subsequent estimated cumulative gastroduodenal ulcer relapse over 6 months for NSAID users who took placebo was 53.5% (95% CI, 36.6%-70.3%). This was reduced to 26.0% (12.1%-39.9%) in patients taking famotidine (P = 0.011)., Conclusions: High-dose famotidine is effective ulcer healing therapy in patients who stop or continue NSAID treatment and significantly reduced the cumulative incidence of gastroduodenal ulcer recurrence compared with placebo when given as maintenance therapy.

Rheumatological conditions often give rise to gastrointestinal (GI) symptoms and vice versa, but the greatest point of contact between rheumatologists and gastroenterologists arises through gastrointestinal toxicity resulting from the use of nonsteroidal antiinflammatory drugs (NSAIDs). Standard NSAIDs are toxic to the entire GI tract. The point prevalence of ulcers in patients on long-term NSAID treatment is about 20% and the annual incidence of complications in these patients is 1% to 4%; 1,200 patients in the United Kingdom die each year as a result. Withdrawing NSAID treatment, or reducing the dose, is not always possible, and approximately 25% of patients require continued long-term antiinflammatory treatment. Misoprostol and acid-suppressing drugs such as ranitidine and omeprazole are helpful as prophylactic treatment in high risk patients, and in healing established ulcers, especially in patients carrying Helicobacter pylori, but there is a pressing need for new, safer antiinflammatory drugs toease the burden of NSAID gastropathy. Selective inhibition of the COX-2 isoform of cyclooxygenase has been proposed as a new and safer therapeutic option. Clinical studies with meloxican, a selective COX-2 inhibitor, support this view. Meloxicam has been extensively studied in arthritis patients and combines antiinflammatory efficacy with a lower incidence of GI toxicity than currently available NSAIDs.

Background & Aims: Leukotriene B4 is a major neutrophil chemoattractant detected during relapse of inflammatory bowel disease and represents a potentional therapeutic target. The aim of this study was to compare the efficacy of zileuton, an active 5-lipoxygenase inhibitor, with mesalazine and placebo in the maintenance of remission in ulcerative colitis., Methods: A double-blind, parallel-group, multicenter, and multinational trial was conducted during a 6-month period in hospital-based patients with inflammatory bowel disease. Three hundred five evaluable patients with ulcerative colitis in remission at the start of the trial were randomized into groups to undergo oral treatment with zileuton (600 mg qid; n = 113), mesalazine (400 mg qid; n = 99), or placebo (n = 111). The primary efficacy outcome was maintenance of remission for 6 months. A multivariate analysis was used to investigate determinants of relapse. Safety was assessed by treatment discontinuation, adverse events, vital signs, and laboratory parameters., Results: After 6 months, 54% of patients receiving zileuton remained in remission compared with 43% receiving placebo (P = 0.094) and 63% on mesalazine (P = 0.266). Relapse rates on mesalazine were significantly lower than those for placebo (P = 0.017). All treatments were well tolerated., Conclusions: Zileuton (600 mg qid) was not significantly better than placebo in the maintenance of remission of ulcerative colitis in this trial and may have limited potential in the treatment of this condition.

Background & Aims: Angiogenesis plays an important role in gastric ulcer healing. Considerable heterogeneity exists between endothelial cells from different blood vessels in vitro. Hitherto, it has not been possible to study gastric angiogenesis using relevant endothelial cells. The aim of this study was to isolate and culture human gastric endothelial (HuGE) cells to allow investigation of gastric ulcer angiogenesis., Methods: Gastric mucosa underwent mechanical and enzymatic disruption. Microvessel fragments and endothelial cells were selected using superparamagnetic beads (Dynabeads; Dynal, Wirral, England) coated with a murine monoclonal anti-human platelet-endothelial cell adhesion molecule 1 antibody. Contaminating nonendothelial cells were removed by mechanical weeding and further Dynabead separation of endothelial cells., Results: HuGE cells have been cultured up to passage 19. HuGE cells formed contact-inhibited monolayers on gelatin coated surfaces and tube-like structures on basement membrane matrices. Indirect immunofluorescence studies confirmed the endothelial nature of these cells. Basic and acidic fibroblast growth factors and vascular endothelial growth factor promoted proliferation (but not epidermal growth factor). HuGE cells synthesized less prostaglandin I2 and E2 compared with human umbilical vein endothelial cells., Conclusions: Pure cultures of HuGE cells can be obtained. Physiologically important differences from large vessel endothelial cells require further investigation.

In 1971 interest in the role of prostaglandins in the gastrointestinal tract was stimulated by the publication of two hypotheses--that aspirin damaged the gastric mucosa by inhibiting prostaglandin synthesis (1) and that cholera toxin caused diarrhea by stimulating it (2). Subsequent research into the gastrointestinal actions of prostaglandins has been considerable and now impinges on clinical practice. This paper reviews the involvement of prostaglandins and related compounds in mucosal protection, in ulcer healing, in diarrhea, and in gastrointestinal inflammation, with particular reference to the growing body of human data.

We investigated the proposition that adaptive cytoprotection (enhanced gastric mucosal integrity) caused by exposure to 20% ethanol in rats is mediated by endogenous prostaglandin synthesis. Experiments were performed both without and with indomethacin sufficient to inhibit ex vivo release of prostaglandin E2 by 56% +/- 9% (2.5 mg/kg) or 86% +/- 4% (10 mg/kg). Twenty percent ethanol significantly reduced both macroscopic and histologic signs of injury caused by subsequent exposure to 100% ethanol whether or not the rats were pretreated with indomethacin. Twenty percent ethanol itself caused extensive superficial disruption of the surface epithelium, so that about half of the mucosa was covered by desquamated debris, but did not stimulate prostaglandin release. We conclude that adaptive cytoprotection still occurs after doses of indomethacin sufficient to cause a profound depression of prostaglandin E2 release. The possibility that it could be due to formation of a protective covering of surface debris is worth further investigation.

We have developed an ultrathin endoscope for repeated endoscopy in unsedated subjects and used it with assessment of bleeding rates to investigate aspirin-induced gastric mucosal injury and its prevention by famotidine. Compared with placebo, 900 mg of aspirin b.i.d. taken for 48 h caused significant endoscopic injury (median grade 3.5, interquartile range 2-4, modified Lanza scale, p less than 0.01), with an increase in mucosal bleeding from 2.0 (geometric mean; 95% confidence limits, 1.1-3.9) microliters/12 min, to 8.3 (2.4-28.8) microliters/12 min (p less than 0.05). Famotidine (20 mg b.i.d.) raised intragastric pH and reduced endoscopic antral injury (median 1.5, interquartile range 0.5-2, p less than 0.05) and bleeding [3.1 (1.2-8.3) microliters/12 min, p less than 0.01] to levels not significantly different from placebo [1 (0-1) and 2.0 (1.1-3.9) microliters/12 min, respectively]. By contrast, 2 mg of famotidine b.i.d. had no significant effect on intragastric pH endoscopic injury or bleeding rates. The two assessments of gastric mucosal injury correlated strongly (r = 0.71, p less than 0.01). The reduction in bleeding with famotidine tended to be higher, the greater the intragastric pH (r = 0.66, p = 0.057). Ultrathin endoscopy is a simple technique that validates gastric mucosal bleeding as a measure of acute gastric mucosal injury in humans. Acid suppression is an effective method of ameliorating this injury.