Multidrug resistance gene-1 polymorphisms and resistance to cyclosporine A in patients with steroid resistant ulcerative colitis

BACKGROUND

Cyclosporine A (CsA) is inconstantly effective in inducing remission in acute attacks of ulcerative colitis (UC) not responding to steroids. This study aimed to establish whether multidrug resistance gene (MDR)1 polymorphisms would be associated with CsA failure.

PATIENTS AND METHODS

The distribution of the different genotypes of single nucleotide polymorphisms (SNP) G2677T/A and C3435T of MDR1 exons 21 and 26, respectively, was studied in 154 patients (mean age, 44 yr) who had received CsA to treat severe attacks of steroid resistant UC in 11 centers in France and Belgium. Patients were classified as CsA failure (n = 50) when they needed colectomy within 30 days after CsA initiation. The SNPs were detected by use of a 5' nuclease allelic discrimination assay.

RESULTS

There was a significant association between the G2677T/A polymorphism distribution (exon 21) and the risk for CsA failure (P = 0.0001). The TT genotype of exon 21 was significantly associated with the risk compared with the two other genotypes (odds ratio, 3.77; 95% confidence interval, 1.42-9.97, P = 0.007). There was no significant association between the genotype C3435T distribution (exon 26) and the risk of CsA failure (P = 0.23).

CONCLUSION

The TT genotype of exon 21 MDR1 polymorphisms is associated with a higher risk of CsA failure in patients with steroid resistant UC. Further studies should be performed to establish whether other treatments could be more efficient to avoid surgery in this subset of patients.

Probiotics, prebiotics, synbiotics: ecological treatment for inflammatory bowel disease?

Ecological treatment may be beneficial in patients with ulcerative colitis

[Malnutrition and low bone mineralisation in adults with cystic fibrosis]

With striking advances in its treatment, cystic fibrosis has turned into an adult condition. Respiratory complications and exocrine pancreatic insufficiency work together to cause malnutrition which reduces survival. The management of low bone mineralization (osteoporosis, osteomalacia) is necessary not only to limit growth failure in younger patients but still in adulthood. We received the literature on malnutrition and bone diseases in adults with cystic fibrosis.

Survival of Lactobacillus casei in the human digestive tract after consumption of fermented milk

A human trial was carried out to assess the ileal and fecal survival of Lactobacillus casei DN-114 001 ingested in fermented milk. Survival rates were up to 51.2% in the ileum and 28.4% in the feces. The probiotic bacterium has the capacity to survive during its transit through the human gut.

Review article: the role of bacteria in onset and perpetuation of inflammatory bowel disease

We review the evidence that strongly suggests a role of the intestinal microbiota in the onset and perpetuation of inflammatory bowel disease (IBD). Experimental studies consisted of suppressing micro-organisms from the microbiota (using germ-free or gnotoxenic animals or antibiotics), introducing new micro-organisms or microbial components (e.g. probiotics, CpG-DNA) or selectively increasing some endogenous bacteria (e.g. using prebiotics). Intervention studies were performed in patients or animal models of spontaneous or chemically-induced colitis. Information was also obtained from observational studies that described the composition of the faecal and mucosal microbiota at various stages of the disease process and in controls. Many have used culture-independent techniques that identify bacteria based on the nucleic acid sequence of ribosomal RNA molecules. Microbiota in patients with IBD seem to be characterized by high concentrations of bacteria in contact with the mucosa, instability, the presence of high numbers of unusual bacteria and sometimes a reduction in the biodiversity. Studies searching for a generalized or localized dysbiosis in IBD are discussed, as well as those trying to identify bacterial molecules and receptors, which may be implicated in triggering the inflammatory process.

Temperature gradient gel electrophoresis of fecal 16S rRNA reveals active Escherichia coli in the microbiota of patients with ulcerative colitis

Previous studies of the endogenous microbiota in patients with ulcerative colitis (UC) have not taken bacterial activity into account, yet bacteria with high transcriptional activity might have a more important pathophysiological role than inactive bacteria. We therefore analyzed the biodiversity of active bacteria in the fecal microbiota of UC patients, in comparison with that of healthy subjects. Feces were collected from nine patients with active UC and from nine healthy controls. Total DNA and RNA were extracted, and 16S ribosomal DNA and RNA were amplified by PCR and reverse transcription-PCR, respectively. Amplification products were compared by means of temporal temperature gradient gel electrophoresis (TTGE). Bands of interest were excised, sequenced, and identified by comparison with the GenBank database (NCBI). The dominant-species diversity based on RNA-derived TTGE profiles was significantly lower for UC patients than for healthy controls (P = 0.01). The mean similarity index between the "present" and "active" microbiota was 74% +/- 18% for UC patients. Comparison of the individual "active" microbiota identified a band that was present for eight UC patients and only two controls (89% versus 22%; P = 0.008). The band was sequenced for 6 patients and always corresponded to Escherichia coli. The biodiversity of active bacteria in the dominant fecal microbiota of patients with UC is lower than that of healthy subjects. E. coli is more represented in the active microbiota of UC patients. The possible pathophysiological role of this difference remains to be determined.

Effects of a 3-mo consumption of short-chain fructo-oligosaccharides on parameters of colorectal carcinogenesis in patients with or without small or large colorectal adenomas

Intervention studies of colorectal adenoma recurrence have demonstrated the need for surrogate markers of the cancer risk. Short-chain fructo-oligosaccharides (sc-FOS) have protective actions on colon carcinogenesis in animal models. We investigated differences in biological markers between adenoma and adenoma-free subjects, before and after 3 mo of daily intake of 10 g sc-FOS, within a multicenter study. After a full colonoscopy, 3 groups were studied at baseline and after 3 mo: 26 subjects with small colorectal adenoma(s), 18 with large adenoma(s), and 30 with no adenoma. At baseline, the mean fecal butyrate concentration was significantly lower in the adenoma groups than in the adenoma-free group (12.01 +/- 5.08 vs. 17.28 +/- 7.34 mmol/g dry weight) but was significantly increased in that group after 3-mo ingestion of sc-FOS (15.7 +/- 8.0 mmol/g; P = 0.02). In subjects without adenoma, sc-FOS ingestion was associated with a decrease in fecal lithocholic acid (P = 0.02) and an increase in cholic acid (P = 0.02), chenodeoxycholic acid (P = 0.04), total primary bile acids (P = 0.03), and ursodeoxycholic acid (P = 0.05). Fecal pH, blood parameters, and crypt cell proliferation were not significantly modified by sc-FOS ingestion in either group. In subjects with and without adenoma, sc-FOS affects some aspects of the colonic environment, which may be involved in prevention of colorectal neoplasia.

Ineffectiveness of Lactobacillus johnsonii LA1 for prophylaxis of postoperative recurrence in Crohn's disease: a randomised, double blind, placebo controlled GETAID trial

BACKGROUND AND AIMS

Early endoscopic recurrence is frequent after intestinal resection for Crohn's disease. Bacteria are involved, and probiotics may modulate immune responses to the intestinal flora. Here we tested the probiotic strain Lactobacillus johnsonii LA1 in this setting.

PATIENTS AND METHODS

This was a randomised, double blind, placebo controlled study. Patients were eligible if they had undergone surgical resection of <1 m, removing all macroscopic lesions within the past 21 days. Patients were randomised to receive two packets per day of lyophilised LA1 (2 x 10(9) cfu) or placebo for six months; no other treatment was allowed. The primary endpoint was endoscopic recurrence at six months, with grade >1 in Rutgeerts' classification or an adapted classification for colonic lesions. Endoscopic score was the maximal grade of ileal and colonic lesions. Analyses were performed primarily on an intent to treat basis.

RESULTS

Ninety eight patients were enrolled (48 in the LA1 group). At six months, endoscopic recurrence was observed in 30/47 patients (64%) in the placebo group and in 21/43 (49%) in the LA1 group (p = 0.15). Per protocol analysis confirmed this result. Endoscopic score distribution did not differ significantly between the LA1 and placebo groups. There were four clinical recurrences in the LA1 group and three in the placebo group.

CONCLUSION

L johnsonii LA1 (4 x 10(9) cfu/day) did not have a sufficient effect, if any, to prevent endoscopic recurrence of Crohn's disease.

Ileal Crohn's disease in a woman with Hermansky-Pudlak syndrome

Hermansky-Pudlak syndrome (HPS) is a rare autosomal recessive disorder characterized by oculocutaneous albinism and platelet dysfunction. A subset of patients also show ceroid deposition, which can result in pulmonary fibrosis or granulomatous colitis. Whether this colitis may be considered Crohn's disease is under debate. We report a case of a patient with HPS associated with inflammatory bowel disease which affected the distal small bowel but not the colon. Ileitis was severe, and recurred rapidly after surgery. Search for mutations in HPS1, ADTB3A, HPS3, HPS4 and for CARD15 were negative. Symptoms and ileal ulcerations which recurred after surgery were successfully treated with azathioprine and infliximab.

[Digestive complications in adults with cystic fibrosis]

In France the median life expectancy of patients with cystic fibrosis (CF) is 36 years and one third of patients are adults. Respiratory disorders are the main determinants of survival during adulthood, although gastrointestinal complications can also have a major impact on quality of life and nutritional status. We reviewed gastro-intestinal and pancreatic manifestations of CF in adults. Some complications (diabetes, distal intestinal obstruction syndrome and acute pancreatitis) are more frequent in adulthood than in childhood. Clinical and therapeutic aspects of specific conditions (such as distal intestinal obstruction syndrome) or atypical presentations (including appendicular complications) are presented herein.

European evidence based consensus on the diagnosis and management of Crohn's disease: current management

This second section of the European Crohn's and Colitis Organisation (ECCO) Consensus on the management of Crohn's disease concerns treatment of active disease, maintenance of medically induced remission, and surgery. The first section on definitions and diagnosis includes the aims and methods of the consensus, as well as sections on diagnosis, pathology, and classification of Crohn's disease. The third section on special situations in Crohn's disease includes postoperative recurrence, fistulating disease, paediatrics, pregnancy, psychosomatics, extraintestinal manifestations, and alternative therapy for Crohn's disease.

Reduced diversity of faecal microbiota in Crohn's disease revealed by a metagenomic approach

BACKGROUND AND AIM

A role for the intestinal microbial community (microbiota) in the onset and chronicity of Crohn's disease (CD) is strongly suspected. However, investigation of such a complex ecosystem is difficult, even with culture independent molecular approaches.

METHODS

We used, for the first time, a comprehensive metagenomic approach to investigate the full range of intestinal microbial diversity. We used a fosmid vector to construct two libraries of genomic DNA isolated directly from faecal samples of six healthy donors and six patients with CD. Bacterial diversity was analysed by screening the two DNA libraries, each composed of 25,000 clones, for the 16S rRNA gene by DNA hybridisation.

RESULTS

Among 1190 selected clones, we identified 125 non-redundant ribotypes mainly represented by the phyla Bacteroidetes and Firmicutes. Among the Firmicutes, 43 distinct ribotypes were identified in the healthy microbiota, compared with only 13 in CD (p<0.025). Fluorescent in situ hybridisation directly targeting 16S rRNA in faecal samples analysed individually (n=12) confirmed the significant reduction in the proportion of bacteria belonging to this phylum in CD patients (p<0.02).

CONCLUSION

The metagenomic approach allowed us to detect a reduced complexity of the bacterial phylum Firmicutes as a signature of the faecal microbiota in patients with CD. It also indicated the presence of new bacterial species.

Efficacy of infliximab in Crohn's disease. Results of a retrospective multicenter study with a 15-month follow-up

OBJECTIVES

To evaluate prescription practices and response to infliximab treatment for Crohn's disease (CD).

PATIENTS AND METHODS

The files of CD patients treated with at least one infusion of infliximab treated in gastroenterology units belonging to university teaching hospitals of the Parisian hospitals group (Assistance Publique-Hôpitaux de Paris (AP-HP) during the year 2000 were analyzed retrospectively.

RESULTS

One hundred and thirty-seven patients (36.0 +/- 12.7 years, 92 females) from 12 centers were studied. Indication for treatment was fistulae or perianal disease in 39% of patients, active Crohn's disease in 45% and mixed conditions in 16%. Mean follow-up was 15.2 +/- 7.2 months. The overall response rate was 85%. No predictive factor of sustained remission could be identified. The mean time to relapse was to 3.9 +/- 3.1 months. Thirty-eight patients were on maintenance therapy at the end of the follow up; 37% exhibiting progressive lost of response to treatment. Immunosuppressive therapy was added to infliximab in 78% of cases but response to infliximab was not modified by addition of immunosuppressive drugs. Adverse events, most frequently minor, were noted in 23% of the patients.

CONCLUSION

This retrospective study confirms the efficacy and safety of infliximab in CD.

Specificities of the fecal microbiota in inflammatory bowel disease

BACKGROUND

Abnormalities have been described in the fecal microbiota of patients with IBD, but it is not known whether they are specific for inflammatory bowel disease (IBD) or to some extent common to other forms of colitis. The aim of this study was to compare the bacterial composition of the dominant fecal microbiota in patients with Crohn's disease (CD), ulcerative colitis (UC), infectious colitis (IC), and in healthy subjects (HS).

METHODS

Fluorescent in situ hybridization adapted to flow cytometry was used to analyze the bacterial composition of fecal samples from 13 patients with active CD, 13 patients with active UC, 5 patients with IC, and 13 HS. We used 6 group-specific probes targeting 16S rRNA and spanning the main phylogenetic groups of the fecal microbiota.

RESULTS

A significantly higher proportion of the total fecal bacteria were recognized by the 6 probes in HS (86.6%+/-12.7) and in IC (84.0%+/-11.7) than in patients with IBD (70.9%+/-15 in CD and 60.1%+/-25.7 in UC). The Clostridium coccoides group was reduced in UC (20.0%+/-13.3 versus 42.0%+/-12.0 in HS; P<.001), whereas the C leptum group was reduced in CD (13.1%+/-11.9 versus 25.2%+/-14.2 in HS; P=.002). The Bacteroides group was more abundant in IC (36.4%+/-22.9) than in the other 3 groups (13.8%+/-11.8 in CD, 11.7%+/-11.7 in UC, 12.1%+/-7.0 in HS; P<.001 for all 3 comparisons).

CONCLUSIONS

In IBD the dominant fecal microbiota comprises unusual bacterial species. Moreover, CD and UC fecal microbiota harbor specific discrepancies and differ from that of IC and healthy subjects.

Living drugs for gastrointestinal diseases: the case for probiotics

Nonpathogenic micro-organisms may contain or produce molecules of potential therapeutic interest. This led to the concept of using ingested living micro-organisms to produce and transport these molecules to targets in the proximal or distal intestine. Several characteristics of this pharmacological approach are very original: potential for in vivo production of active molecules, for targeting immune cells, for presenting immunogenic molecules in a microbial context, for duodenal delivery using bile sensitivity. Probiotics have been studied for some decades and more recently worm eggs have also received some interest. This paper summarizes facts (especially results of randomized controlled trials and pharmacokinetic studies), and ideas about the use of probiotics to treat or prevent gastrointestinal diseases. The safety of this approach (exceptional cases of infections have been observed), and the potential for using new agents or genetically modified micro-organisms (ongoing trials in humans with Crohn's disease) are also discussed.

Search for localized dysbiosis in Crohn's disease ulcerations by temporal temperature gradient gel electrophoresis of 16S rRNA

The mucosa-associated microbiota lining the gut epithelium might play a central role in the activation and/or perpetuation of mucosal inflammation in Crohn's disease (CD). We sought for localized dysbiosis by comparing the biodiversity and composition of the microbiotas in ulcerated and nonulcerated mucosal samples from patients with CD. Biopsy samples (n = 75) of ulcerated and adjacent nonulcerated mucosa were collected during colonoscopy from 15 patients, from the ileum, right colon, left colon, and rectum. Temporal temperature gradient gel electrophoresis (TTGE) of bacterial 16S rRNAs was used to evaluate the dominant bacterial species. TTGE profiles were compared using software that calculates similarity percentages. For a given patient, average similarity indexes between ulcerated and nonulcerated mucosal TTGE profiles ranged from 95.2% +/- 4.2% to 97.9% +/- 1.7% (means +/- standard deviations) for the different segments. The mean values did not differ significantly. Average interindividual similarity indexes for a given segment among the different patients ranged from 33.6% +/- 15.5% to 42.0% +/- 25.6%. In CD, the dominant microbiotas do not differ qualitatively between ulcerated and nonulcerated mucosae. Biodiversity remains high in ulcerated mucosa. This argues against a pathogenic role of localized qualitative dysbiosis in CD-associated ulceration.

Small bowel adenocarcinoma in patients with Crohn's disease compared with small bowel adenocarcinoma de novo

BACKGROUND

Data concerning small bowel adenocarcinoma (SBA) in Crohn's disease (CD) come from case reports and small retrospective series. The aim of this study was to further describe SBA in patients with CD and compare it with SBA de novo.

METHODS

Twenty patients with CD with SBA recruited in French university hospitals were studied and compared with 40 patients with SBA de novo recruited from a population-based registry. SBA occurred after a median time of 15 years of CD and was located within the inflamed areas of the ileum (n=19) or jejunum (n=1), whereas in patients with SBA de novo, it was distributed all along the small intestine. Median age at diagnosis of SBA was 47 years (range, 33-72 yr) in patients with CD and 68 years (range, 41-95 yr) in those with SBA de novo.

RESULTS

The cumulative risk of SBA, assessed in a subgroup of patients, was 0.2% and 2.2% after 10 and 25 years of ileal CD, respectively. SBA accounted for 25% and 45% of the risk of gastrointestinal carcinoma after 10 and 25 years of CD, respectively. Diagnosis was made preoperatively in 1/20 patients with CD and 22/40 patients with SBA de novo. Signet ring cells were found in 35% of patients with CD but not in patients with SBA de novo. Relative survival was not significantly different in these 2 categories of patients (54 versus 37% and 35 versus 30% in patients with and without CD at 2 and 5 yr, respectively).

CONCLUSIONS

SBA in CD is different from SBA de novo. It arises from longstanding ileal inflammation and is difficult to diagnose. SBA cumulative risk increases after 10 years of CD and is likely to cause premature mortality in patients with early-onset CD.