Eduard Cabré

How Effective Is Enteral Nutrition in Inducing Clinical Remission in Active Crohn's Disease? A Meta-Analysis of the Randomized Clinical Trials

BACKGROUND The purpose of the study was to evaluate, using meta-analysis techniques, whether enteral nutrition is effective in inducing clinical remission in active Crohns disease. METHODS Randomized trials either comparing enteral nutrition with steroids or comparing elemental (amino acid-based) with nonelemental diets were selected using MEDLINE (1984 to 1994), reference lists from published articles, reviews, and abstracts from major gastrointestinal meetings. Sixteen studies fulfilled the inclusion criteria (four published as abstracts). Crude rates for induction of remission were collected on an intention-to-treat basis by three independent observers. Each study was given a quality score, based on predetermined criteria. RESULTS The pooled odds ratio (OR) for all type of enteral diets compared with steroid therapy was 0.35 (95% CI, 0.23 to 0.53). This result was similar for the best studies (by quality score) combined, for trials using tube feeding combined, and when noncompliant patients were withdrawn. Further subgroup analyses were conducted on the basis of the type of diet administered. Peptide-based diets were significantly inferior to steroids (pooled OR, 0.32; CI, 0.20 to 0.52). There was a trend to lower remission rate after elemental diets than after steroids (pooled OR, 0.44; CI 0.17 to 1.12). On the other hand, pooled OR for whole protein-based diets compared with elemental diets was 1.28 (CI, 0.40 to 4.02). CONCLUSIONS Data available to date show that steroids are better than enteral nutrition to induce remission in active Crohns disease. These results are more evident when peptide-based diets are administered, but they are not conclusive when either elemental or whole protein-based diets are used.

Polymeric enteral diets as primary treatment of active Crohn's disease: a prospective steroid controlled trial.

Thirty two patients with active Crohns disease were included in a controlled randomised trial to determine the efficacy and safety of polymeric enteral nutrition compared with steroids, to achieve and maintain clinical remission. The polymeric diet was administered through a fine bore nasogastric tube by continuous, pump assisted infusion (2800 (SEM 120) kcal/day). The steroid group received 1 mg/kg/day of prednisone. Both treatments were effective in inducing clinical remission: 15 of the 17 patients given steroids and 12 of the 15 patients assigned to the polymeric diet went into clinical remission (defined by a Van Hees index < 120) within four weeks of treatment. The percentage reduction of the Van Hees index was 34.8 (4.9)% for steroids and 32.3 (5)% for enteral nutrition (mean difference 2.5%; 95% CI--11.8% to +16.8%). Mean time elapsed to achieve remission was similar in both groups (2.0 (1) v 2.4 (1.2) weeks). Tolerance of the enteral diet was excellent. Four patients in the steroid group had mild complications attributable to this treatment. Ten patients (66.6%) in the steroid group and five (41.6%) in the enteral nutrition group relapsed within a year of discharge, but no differences were found in the cumulative probability of relapse during the follow up period. These results suggest that polymeric enteral nutrition is as safe and effective as steroids in inducing short term remission in active Crohns disease.

Fat composition may be a clue to explain the primary therapeutic effect of enteral nutrition in Crohn's disease: results of a double blind randomised multicentre European trial

Background: Dietary fat has been suggested to determine the therapeutic effect of enteral diets in Crohns disease. Aim: To assess the efficacy of two whole protein based diets with different fat compositions (n6 polyunsaturated fatty acids v monounsaturated fatty acids) in inducing clinical remission in active Crohns disease compared with steroids. Methods: Sixty two patients with active Crohns disease were randomised to receive, for not more than 4 weeks: (a) a polymeric enteral diet containing 35 g of lipids per 1000 kcal, high in oleate (79%) and low in linoleate (6.5%) (PEN1), (b) an identical enteral diet except for the type of fat which was high in linoleate (45%) and low in oleate (28%) (PEN2), or (c) oral prednisone (1 mg/kg/day). Diets were double blindly administered. The steroid group received a conventional ward diet. Treatment failure was considered when remission was not achieved at week 4. Clinical activity and biological and nutritional parameters were monitored. Independent predictors of remission were identified by stepwise logistic regression analysis. Results: Overall remission rates (by intention to treat) were 20% (4/20) for PEN1, 52% (12/23) for PEN2, and 79% (15/19) for steroids (overall p=0.001; p<0.0005 steroids v PEN1, and p=0.056 PEN2 v PEN1). After excluding those patients who were non-compliant during the first week (per protocol analysis), remission rates were 27%, 63%, and 79%, respectively (p=0.008, steroids and PEN2 v PEN1). After adjusting for confounding variables, PEN1 remained significantly associated with a poor response. Conclusion: The type of dietary fat may be of importance for the primary therapeutic effect of enteral nutrition in active Crohns disease.

Cytomegalovirus infection in patients with inflammatory bowel disease

OBJECTIVE: It has been suggested that, in inflammatory bowel disease, cytomegalovirus behaves in the intestine as a nonpathogenic bystander, and even its finding in intestinal mucosa has unclear clinical relevance. We report our experience with a small series of patients with refractory inflammatory bowel disease and cytomegalovirus infection and their clinical outcome. METHODS AND RESULTS: Nine patients with moderate-severe attacks of inflammatory bowel disease did not respond to i.v. prednisone (1 mg/kg/day) for a mean of 24 days. Four of these patients were further treated with i.v. cyclosporine A (4 mg/kg/day). Cytomegalovirus infection was diagnosed in two patients after resection for treatment failure. In the remaining patients, cytomegalovirus infection was diagnosed in endoscopic mucosal biopsies and i.v. ganciclovir was then administered at a dose of 10 mg/kg/day for 2-3 wk. Five of these patients went into clinical remission, allowing corticosteroid and cyclosporine A discontinuation. Follow-up biopsies were performed and in all cases cytomegalovirus could not be detected in the colonic tissue. Two patients needed to be treated with intravenous cyclosporine A after antiviral therapy because of persistence of clinical symptoms despite the elimination of cytomegalovirus infection. CONCLUSIONS: Cytomegalovirus infection may play a role in the natural history of refractory inflammatory bowel disease and in some of its complications. The clearance of cytomegalovirus in colonic mucosa may lead some of these patients to remission.

Effect of olive oil on early and late events of colon carcinogenesis in rats: modulation of arachidonic acid metabolism and local prostaglandin E2 synthesis

BACKGROUND Animal model studies have shown that the colon tumour promoting effect of dietary fat depends not only on the amount but on its fatty acid composition. With respect to this, the effect of n9 fatty acids, present in olive oil, on colon carcinogenesis has been scarcely investigated. AIMS To assess the effect of an n9 fat diet on precancer events, carcinoma development, and changes in mucosal fatty acid composition and prostaglandin (PG)E2 formation in male Sprague-Dawley rats with azoxymethane induced colon cancer. METHODS Rats were divided into three groups to receive isocaloric diets (5% of the energy as fat) rich in n9, n3, or n6 fat, and were administered azoxymethane subcutaneously once a week for 11 weeks at a dose rate of 7.4 mg/kg body weight. Vehicle treated groups received an equal volume of normal saline. Groups of animals were colectomised at weeks 12 and 19 after the first dose of azoxymethane or saline. Mucosal fatty acids were assessed at 12 and 19 weeks. Aberrant crypt foci and the in vivo intracolonic release of PGE2 were assessed at week 12, and tumour formation at week 19. RESULTS Rats on the n6 diet were found to have colonic aberrant crypt foci and adenocarcinomas more often than those consuming either the n9 or n3 diet. There were no differences between the rats on the n9 and n3 diets. On the other hand, administration of both n9 and n3 diets was associated with a decrease in mucosal arachidonate concentrations as compared with the n6 diet. Carcinogen treatment induced an appreciable increase in PGE2 formation in rats fed the n6 diet, but not in those fed the n3 and n9 diets. CONCLUSIONS Dietary olive oil prevented the development of aberrant crypt foci and colon carcinomas in rats, suggesting that olive oil may have chemopreventive activity against colon carcinogenesis. These effects may be partly due to modulation of arachidonic acid metabolism and local PGE2synthesis.

Cytomegalovirus infection in ulcerative colitis: A prospective, comparative study on prevalence and diagnostic strategy

Background: Cytomegalovirus (CMV) infection has been reported in ulcerative colitis (UC), especially in severe, steroid‐refractory disease. However, its role in steroid‐refractoriness remains unknown. Our goals were to evaluate the prevalence of CMV disease in UC, the best diagnostic strategy, and the influence of disease activity and/or treatment in its development. Methods: Prospective, observational study including 114 subjects with active UC requiring intravenous steroids, steroid‐refractory UC, inactive UC on mesalamine, inactive UC on azathioprine, and healthy controls. CMV antibodies, pp65‐antigenemia, and rectal biopsies for hematoxylin and eosin staining, immunohistochemistry, and CMV‐pp67 mRNA were performed. These procedures were repeated after medical treatment only in patients with active UC. CMV disease was defined by the presence of inclusion bodies and/or positive immunohistochemistry in colonic biopsies. Results: CMV disease was found in 6 steroid‐refractory, CMV‐IgG‐positive UC patients but not among controls, inactive UC, or steroid‐responding UC patients. In 5 out of the 6 patients, CMV disease was diagnosed after 7–10 days on cyclosporine. Conclusions: CMV disease in UC only affects seropositive, steroid‐refractory UC patients. Steroid/cyclosporine treatment together with disease activity may predispose to latent colonic CMV reactivation. The impact of antiviral therapy on the clinical outcome of these patients remains to be elucidated.

Translocated intenstinal bacteria cause spontaneous bacterial peritonitis in cirrhotic rats: molecular epidemiologic evidence

BACKGROUND/AIMS Intestinal bacterial translocation is common in cirrhotic rats with spontaneous bacterial peritonitis, and it is thought to play a major pathogenic role. There has so far been no evidence for clonality between bacteria isolated from intestine and ascites. This study aimed to use molecular epidemiology techniques to show that spontaneous bacterial peritonitis is due to translocated intestinal bacteria. METHODS Samples of ascitic fluid, portal blood, mesenteric lymph nodes and ileal contents from healthy (n=10) and ascitic cirrhotic rats with (n=12) or without (n=15) spontaneous bacterial peritonitis were cultured. In six infected rats, DNA macrorestriction fragments of 30 bacterial isolates [Escherichia coli (n=13), Enterococcus faecalis (n=12) and Proteus mirabilis (n=5)] from ascites (n=8), mesenteric lymph nodes (n=7), portal blood (n=6), and ileal flora (n=9) were compared. RESULTS Bacterial translocation was more frequent in animals with (58%) than in those without spontaneous bacterial peritonitis (20%, p=0.049) or controls (10%, p=0.026). The same bacterial strain was simultaneously isolated in ascites and in mesenteric lymph nodes and/or ileum in 7/8 (87%) instances. The identity rate for bacteria present in both ascites and mesenteric lymph nodes was 80% (4/5). Likewise, identity was demonstrated in 3/4 instances of bacteria found in both ascites and portal blood. CONCLUSIONS These results indicate that spontaneous bacterial peritonitis in cirrhotic rats is mainly due to intestinal bacteria translocated to mesenteric lymph nodes. Portal blood could be a less frequent route.

Bacterial translocation in cirrhotic rats. Its role in the development of spontaneous bacterial peritonitis.

Bacterial translocation occurs in ascitic cirrhotic rats, but its association with ascites infection is unknown. The aim of this study was to assess the relation between bacterial translocation and ascites infection in cirrhotic rats. Male Sprague-Dawley rats were induced to cirrhosis with intragastric CCl4. Ascitic fluid, portal and peripheral blood, mesenteric lymph nodes, liver and spleen samples were cultured before death in those cirrhotic rats with less (group A) or more (group B) than 250 polymorphonuclear neutrophils/mm3 in ascitic fluid, as well as in healthy control rats. Histological examination of jejunum, ileum, and caecum was also performed. Bacterial translocation occurred in 45% of ascitic rats (without differences between groups A and B), but in 0% controls (p = 0.01). Bacterial translocation was associated with positive ascitic fluid culture in 60% of the cases. In all of them the same bacterial species was isolated in both mesenteric lymph node and ascitic fluid. Submucosal caecal oedema (100%), ileal lymphangiectasia (41%), and caecal inflammatory infiltrate (41%) occurred in ascitic rats, the last being associated with ascitic fluid positive culture (p = 0.04). These results suggests that bacterial translocation occurs frequently in ascitic cirrhotic rats, and may play a permissive, but not unique, part in a number of ascites infections. Whether histological changes seen in cirrhotic ascitic rats favour bacterial translocation remains to be elucidated.

Safety of thiopurine therapy in inflammatory bowel disease: long-term follow-up study of 3931 patients.

Background:To evaluate the safety of thiopurines in patients with inflammatory bowel disease. To identify predictive factors associated with the development of thiopurine-induced adverse events. Methods:Long-term incidence of adverse events was estimated in patients from a prospectively maintained Spanish nationwide database using Kaplan–Meier analysis. Cox regression analysis was performed to identify potential predictive factors of adverse events. Results:Three thousand nine hundred and thirty-one patients were included. Ninety-five percent of patients were on azathioprine. The median follow-up with thiopurines was 44 months (range, 0–420). Adverse events occurred at a median of 1 month after starting treatment. The cumulative incidence of adverse events was 26%, with an annual risk of 7% per patient-year of treatment. Most frequent adverse events were nausea (8%), hepatotoxicity (4%), myelotoxicity (4%), and pancreatitis (4%). Four patients had lymphoma. Female and Crohns disease increased the risk of having nausea. The risk of hepatotoxicity was lower in females and higher in Crohns disease. The risk of myelotoxicity was significantly higher in patients treated with mercaptopurine and in females. The risk of pancreatitis was higher in Crohns disease. Overall, 17% of patients discontinued thiopurine treatment due to adverse events. Thirty-seven percent of these patients started thiopurines again and 40% of them had adverse events again. Conclusions:As many as 1 of 4 patients on thiopurine therapy had adverse events during follow-up. A relatively high proportion of patients (17%) had to discontinue the treatment with thiopurines due to adverse events. However, more than half of patients that restarted thiopurine treatment after its discontinuation due to adverse events tolerated it. Several predictive factors for some adverse events have been identified.

Spontaneous bacterial peritonitis in patients with cirrhosis undergoing selective intestinal decontamination: A retrospective study of 229 spontaneous bacterial peritonitis episodes

BACKGROUND/AIMS Selective intestinal decontamination with norfloxacin is widely used to prevent spontaneous bacterial infections in cirrhosis. The study was performed to compare the spontaneous bacterial peritonitis occurring in patients with and without prophylactic norfloxacin. METHODS Two hundred and twenty-nine consecutive episodes of spontaneous bacterial peritonitis, (193 in patients without (Group A) and 36 in patients with norfloxacin prophylaxis (Group B)), were retrospectively analyzed. In 100 episodes (86 and 14, respectively), the responsible organism was isolated in ascitic fluid. RESULTS Clinical and laboratory data at diagnosis were comparable in both groups. There were marked differences (p < 0.001) between group A and B in the frequency of peritonitis caused by gram-negative (67.4% vs. 14.3%) and gram-positive (30.2% vs. 78.6%) bacteria. There were three polymicrobial episodes. Bacteria resistant to cefotaxime and gram-negative bacilli resistant to quinolones were isolated in ascitic fluid in nine (seven in Group A and two in Group B) and three episodes (all in Group A), respectively. No differences in the course of infection and patient survival were observed between groups. CONCLUSIONS Spontaneous bacterial peritonitis in patients with and without prophylaxis with norfloxacin are not different in clinical features, response to treatment and prognosis. Spontaneous bacterial peritonitis caused by gram-negative organisms resistant to quinolones is extremely uncommon in patients with cirrhosis receiving prophylactic norfloxacin.