Herbert Lochs

Spatial organization and composition of the mucosal flora in patients with inflammatory bowel disease.

ABSTRACT The composition and spatial organization of the mucosal flora in biopsy specimens from patients with inflammatory bowel disease (IBD; either Crohns disease or ulcerative colitis), self-limiting colitis, irritable-bowel syndrome (IBS), and healthy controls were investigated by using a broad range of fluorescent bacterial group-specific rRNA-targeted oligonucleotide probes. Each group included 20 subjects. Ten patients who had IBD and who were being treated with antibiotics were also studied. Use of nonaqueous Carnoy fixative to preserve the mucus layer was crucial for detection of bacteria adherent to the mucosal surface (mucosal bacteria). No biofilm was detectable in formalin-fixed biopsy specimens. Mucosal bacteria were found at concentrations greater than 109/ml in 90 to 95% of IBD patients, 95% of patients with self-limiting colitis, 65% of IBS patients, and 35% of healthy controls. The mean density of the mucosal biofilm was 2 powers higher in IBD patients than in patients with IBS or controls, and bacteria were mostly adherent. Bacteroides fragilis was responsible for >60% of the biofilm mass in patients with IBD but for only 30% of the biofilm mass in patients with self-limiting colitis and <15% of the biofilm mass in patients with IBS. In contrast, bacteria which positively hybridized with the probe specific for Eubacterium rectale-Clostridium coccoides accounted for >40% of the biofilm in IBS patients but for <15% of the biofilm in IBD patients. In patients treated with (5-ASA) or antibiotics, the biofilm could be detected with 4,6-diamidino-2-phenylindole but did not hybridize with fluorescence in situ hybridization probes. A Bacteroides fragilis biofilm is the main feature of IBD. This was not previously recognized due to a lack of appropriate tissue fixation. Both 5-ASA and antibiotics suppress but do not eliminate the adherent biofilm.

Genetic basis for increased intestinal permeability in families with Crohn’s disease: role of CARD15 3020insC mutation?

Background and aim: A genetically impaired intestinal barrier function has long been suspected to be a predisposing factor for Crohn’s disease (CD). Recently, mutations of the capsase recruitment domain family, member 15 (CARD15) gene have been identified and associated with CD. We hypothesise that a CARD15 mutation may be associated with an impaired intestinal barrier. Methods: We studied 128 patients with quiescent CD, 129 first degree relatives (CD-R), 66 non-related household members (CD-NR), and 96 healthy controls. The three most common CARD15 polymorphisms (R702W, G908R, and 3020insC) were analysed and intestinal permeability was determined by the lactulose/mannitol ratio. Results: Intestinal permeability was significantly increased in CD and CD-R groups compared with CD-NR and controls. Values above the normal range were seen in 44% of CD and 26% of CD-R but only in 6% of CD-NR, and in none of the controls. A household community with CD patients, representing a common environment, was not associated with increased intestinal permeability in family members. However, 40% of CD first degree relatives carrying a CARD15 3020insC mutation and 75% (3/4) of those CD-R with combined 3020insC and R702W mutations had increased intestinal permeability compared with only 15% of wild-types, indicating a genetic influence on barrier function. R702W and G908R mutations were not associated with high permeability. Conclusions: In healthy first degree relatives, high mucosal permeability is associated with the presence of a CARD15 3020insC mutation. This indicates that genetic factors may be involved in impairment of intestinal barrier function in families with IBD.

Small bowel involvement in Crohn’s disease: a prospective comparison of wireless capsule endoscopy and computed tomography enteroclysis

Background: Wireless capsule endoscopy (WCE) offers endoscopic access to the small bowel and may therefore change diagnostic and therapeutic strategies in small bowel diseases. Aim: The aim of this prospective study was to validate the gain in information and therapeutic impact of WCE in patients with Crohn’s disease. Methods: Fifty six consecutive patients with Crohn’s disease underwent computed tomography (CT) enteroclysis, and if stenoses <10 mm were excluded, WCE was carried out. Results: In 15 patients (27%), WCE could not be performed due to strictures detected by CT enteroclysis. From the other 41 patients, jejunal or ileal lesions were found in 25 patients by WCE compared with 12 by CT enteroclysis (p = 0.004). This gain in information was mainly due to detection of small mucosal lesions such as villous denudation, aphthoid ulcerations, or erosions. Both methods were not significantly different in the detection of lesions in the terminal/neoterminal ileum (WCE 24 patients, CT enteroclysis 20 patients). Therapy was changed due to WCE findings in 10 patients. Consecutively, all of them improved clinically. Conclusions: Capsule endoscopy improves the diagnosis of small bowel Crohn’s disease. This may have significant therapeutic impact.

Prophylaxis of postoperative relapse in Crohn's disease with mesalamine: European cooperative Crohn's disease study VI

BACKGROUND & AIMS This study investigated if long-term treatment with high-dose mesalamine reduces the risk of clinical relapse of Crohns disease after surgical resection. METHODS In a prospective, randomized, double-blind, multicenter study, 4 g of mesalamine (Pentasa; Ferring A/S, Vanlose, Denmark) daily was compared with placebo in 318 patients. Treatment was started within 10 days after resective surgery and continued for 18 months. Primary outcome parameter was clinical relapse as defined by an increase in Crohns Disease Activity Index, reoperation, septic complication, or newly developed fistula. Risk factors for recurrence were prospectively defined to be analyzed in a stepwise proportional hazards model. RESULTS Cumulative relapse rates (+/-SE) after 18 months were 24.5% +/- 3.6% and 31.4% +/- 3.7% in the mesalamine (n = 152) and placebo (n = 166) groups, respectively (P = 0.10, log-rank test, 1-sided). Retrospective analysis showed a significantly reduced relapse rate with mesalamine only in a subgroup of patients with isolated small bowel disease (n = 124; 21.8% +/- 5.6% vs. 39.7% +/- 6.1%; P = 0.02, log-rank test). Probability of relapse was predominantly influenced by the duration of disease (P = 0.0006) and steroid intake before surgery (additional risk, P = 0.0003). CONCLUSIONS Eighteen months of mesalamine, 4 g daily, did not significantly affect the postoperative course of Crohns disease. Some relapse-preventing effect was found in patients with isolated small bowel disease.

Photodynamic therapy of nonresectable cholangiocarcinoma

BACKGROUND & AIMS Successful treatment in nonresectable Bismuth type III and IV cholangiocarcinoma is seldom achieved. The aim of this study was to evaluate the effect of photodynamic therapy on cholestasis, quality of life, and survival in these patients. METHODS Nine patients with advanced nonresectable cholangiocarcinomas Bismuth type III and IV, who showed no sufficient drainage (bilirubin decrease <50%) after endoscopic stent insertion, underwent photodynamic therapy. Two days after intravenous application of a hematoporphyrin derivate, intraluminal photoactivation was performed cholangioscopically. Serum bilirubin, quality of life, and survival time were assessed in two monthly intervals after photodynamic therapy. RESULTS After photodynamic therapy, bilirubin serum levels declined from 318 +/- 72 to 103 +/- 35 micromol/L (P = 0.0039) with no significant increase during the two monthly follow-ups. Quality of life indices improved dramatically and remained stable (e.g., Karnofsky index from 32.2% +/- 8.13% to 68.9% +/- 6.1%; P = 0.0078). Thirty-day mortality was 0%, and median survival time was 439 days. CONCLUSIONS This study provides clear evidence that photodynamic therapy is effective in restoring biliary drainage and improving quality of life in patients with nonresectable disseminated cholangiocarcinomas Bismuth type III and IV. Compared with published data, survival time seems to be prolonged.

Adherent Biofilms in Bacterial Vaginosis

OBJECTIVE: Bacterial vaginosis is a common infectious disorder. Although known since ancient times, little progress has occurred in identifying causal factors. Our aims were to study the bacterial community structure and the spatial organization of microbiota on the epithelial surfaces of vaginal biopsy specimens. METHODS: We investigated the composition and spatial organization of bacteria associated with the vaginal epithelium in biopsy specimens from 20 patients with bacterial vaginosis and 40 normal premenopausal and postmenopausal controls using a broad range of fluorescent bacterial group-specific rRNA-targeted oligonucleotide probes. RESULTS: Bacterial vaginosis was associated with greater occurrence and higher concentrations of a variety of bacterial groups. However, only Gardnerella vaginalis developed a characteristic adherent biofilm that was specific for bacterial vaginosis. CONCLUSION: A biofilm comprised of confluent G vaginalis with other bacterial groups incorporated in the adherent layer is a prominent feature of bacterial vaginosis. LEVEL OF EVIDENCE: II-2

Comparative study of the intestinal mucus barrier in normal and inflamed colon

Aim: To study the role of mucus in the spatial separation of intestinal bacteria from mucosa. Patients and methods: Mucus barrier characteristics were evaluated using histological material obtained by biopsy from purged colon, colon prepared with enema and material from untreated appendices fixed with non-aqueous Carnoy solution. Bacteria were evaluated using fluorescence in situ hybridization, with bacterial 16S RNA probes and related to the periodic acid Schiff alcian blue stain. Biopsies from controls (n = 20), patients with self-limiting colitis (SLC; n = 20), ulcerative colitis (n = 20) and 60 randomly selected appendices were investigated. Results: The mucosal surface beneath the mucus layer was free of bacteria in ⩾80% of the normal appendices and biopsies from controls. The thickness of the mucus layer and its spread decreased with increasing severity of the inflammation; the epithelial surface showed bacterial adherence, epithelial tissue defects and deep mucosal infiltration with bacteria and leucocytes. Bacteria and leucocytes were found within mucus in all biopsy specimens from patients with ulcerative colitis, SLC, and acute appendicitis. The concentration of bacteria within mucus was inversely correlated to the numbers of leucocytes. Conclusions: The large bowel mucus layer effectively prevents contact between the highly concentrated luminal bacteria and the epithelial cells in all parts of the normal colon. Colonic inflammation is always accompanied by breaks in the mucus barrier. Although the inflammatory response gradually reduces the number of bacteria in mucus and faeces, the inflammation itself is not capable of preventing bacterial migration, adherence to and invasion of the mucosa.

Increased secretion of pro-inflammatory cytokines by circulating polymorphonuclear neutrophils and regulation by interleukin 10 during intestinal inflammation

Background—Concentrations of pro-inflammatory cytokines are increased in the intestinal mucosa of patients with active inflammatory bowel disease (IBD). Polymorphonuclear neutrophil granulocytes (PMN) are the most abundant cell type in intestinal lesions in IBD. Interleukin 10 (IL-10) is an important contra-inflammatory cytokine which induces downregulation of pro-inflammatory cytokines. Aims—To investigate whether PMN from patients with IBD or infectious colitis, respectively, secrete increased amounts of pro-inflammatory cytokines and can be regulated by IL-10. Methods—Secretion (ELISA) as well as corresponding mRNA levels (semiquantitative RT-PCR) of pro-inflammatory cytokines (IL-1β, TNF-α) and of IL-1 receptor antagonist were assessed in peripheral PMN. Results—PMN from patients with IBD are primed to secrete enhanced amounts of pro-inflammatory cytokines accompanied by detection of corresponding mRNAs in comparison with normal controls. This finding is not specific for IBD but rather reflects intestinal inflammation in general. IL-10 markedly inhibited pro-inflammatory cytokine secretion as well as corresponding mRNA concentrations. Conclusions—PMN are an important source of pro-inflammatory cytokines in patients with intestinal inflammation and can be downregulated by IL-10.

Recombinant Erythropoietin for the Treatment of Anemia in Inflammatory Bowel Disease

BACKGROUND Some patients with inflammatory bowel disease have anemia that is refractory to treatment with iron and vitamins. We examined whether administering iron and recombinant erythropoietin could raise hemoglobin levels in such patients. METHODS Thirty-four patients with inflammatory bowel disease (15 with ulcerative colitis and 19 with Crohns disease) and anemia refractory to iron therapy (hemoglobin concentrations below 10.0 g per deciliter [6.2 mmol per liter]) were randomly assigned in a prospective, double-blind, 12-week trial to receive either oral iron (100 mg per day) and subcutaneous erythropoietin (150 U per kilogram of body weight twice per week) (n=17) or oral iron and placebo (n=17). The primary measure of efficacy was an increase in hemoglobin levels of more than 1.0 g per deciliter (0.62 mmol per liter). Additional analyses were performed with other patients with inflammatory bowel disease. RESULTS The severity of anemia was related to clinical disease activity as well as to in vitro monocyte secretion of interleukin-1 beta, a proinflammatory cytokine. Serum erythropoietin concentrations were increased in 52 randomly selected outpatients with inflammatory bowel disease and anemia, but the concentrations were inadequate in relation to the degree of anemia. Twelve weeks of therapy with recombinant erythropoietin and oral iron increased mean (+/-SE) hemoglobin concentrations from 8.81+/-0.27 g per deciliter (5.47+/-0.17 micromol per liter) to 10.52+/-0.41 g per deciliter (6.5+/-0.25 micromol per liter), whereas hemoglobin concentrations in the placebo group decreased from 8.69+/-0.11 g per deciliter (5.4+/-0.068 micromol per liter) to 7.84+/- 0.33 g per deciliter (4.9+/-0.2 mmol per liter) (P<0.001). After 12 weeks, hemoglobin levels had increased by more than 1.0 g per deciliter in 82 percent of the patients in the erythropoietin group, as compared with 24 percent of those in the placebo group (P=0.002). There were five treatment failures in the placebo group and two in the erythropoietin group (P=0.18); treatment failure was defined as a decrease in hemoglobin levels of more than 2.0 g per deciliter (1.24 micromol per liter) to a value below 8.0 g per deciliter (4.96 micromol per liter) or any decrease to less than 6.5 g per deciliter (4.03 micromol per liter). CONCLUSIONS In patients with inflammatory bowel disease and anemia refractory to treatment with iron and vitamins, treatment with oral iron and recombinant erythropoietin can raise hemoglobin levels.

Association between intraepithelial Escherichia coli and colorectal cancer

BACKGROUND & AIMS Although multiple studies have focused on Helicobacter pylori, little is known about the mucosa-associated flora of the colon. The aim of this study was to detect bacteria directly in colonic mucosa from patients screened for colorectal cancer. METHODS Bacteria were quantified with the polymerase chain reaction and identified by comparative sequence analysis in colonoscopic biopsy specimens from 31 asymptomatic and 34 symptomatic controls with normal colonoscopic findings, 29 patients with colonic adenoma, and 31 patients with colorectal carcinoma. In 41 patients, intra- and extracellular location of bacteria was confirmed with the gentamicin protection assay. RESULTS No bacteria were detected in biopsy specimens from 97% of asymptomatic and 69% of symptomatic controls. In contrast, bacterial concentrations of 10(3)-10(5) colony-forming units per microliter were detected in biopsy specimens from both malignant and macroscopically normal tissue in 90% and 93% of patients with adenoma and carcinoma, respectively. E. coli and coli-like bacteria were shown to colonize the colonic mucosa in 82% of these patients. The gentamicin protection assay indicated that E. coli was partially intracellular in 87% of patients with adenoma and carcinoma and in none of the controls. CONCLUSIONS The colonic mucosa of patients with colorectal carcinoma but not normal colonic mucosa is colonized by intracellular E. coli.