[Predictors of clinical response in patients with ulcerative colitis treated with granulocyte-monocyte apheresis: analysis of the apheresis registry data]. / Predittori di risposta clinica in pazienti affetti da colite ulcerosa trattati con granulocito-monocito aferesi: analisi dei dati del registro aferesi.

We analyzed predictors of clinical response after a cycle of granulocytemonocyte apheresis in 173 patients with ulcerative colitis. Hemoglobin levels independently predicted good clinical outcome.

The Italian Registry of Therapeutic Apheresis: granulocyte-monocyte apheresis in the treatment of inflammatory bowel disease. A multicentric study.

Leukocytes are thought to play an important role in the pathogenesis of inflammatory bowel diseases; granulocyte-monocyte adsorptive (GMA) apheresis, an extracorporeal technique aimed at removing activated circulating leukocytes from the blood, may represent a safe and effective therapeutic tool in these patients. The Italian Registry of Therapeutic Apheresis performed an observational, multicentric study involving 24 Gastroenterology Units. In this study, laboratory data and clinical outcomes of 230 patients (148 males, mean age 43.5 years) affected with ulcerative colitis (UC, n = 194) or Crohn's disease (CD, n = 36) who underwent one or more cycles of GMA were analyzed. Each cycle consisted of five GMA treatments. The patients were followed up for a mean of 8.7 (min. 3 to max. 12) months. At 3 months, positive outcome was achieved in 77.7% of UC patients (72.0% remission, 5.7% clinical response) and 61.3% of CD patients (54.8% remission, 6.5% clinical response). The cumulative proportion of positive outcome at 12 months was 87.1% for UC patients (83.7% remission, 3.4% clinical response) and 77.4% for CD patients (74.2% remission, 3.2% clinical response). No single clinical or laboratory parameter among those analyzed (age, sex, disease characteristics, history of smoking, medication history, baseline values of clinical activity index (CAI)/Crohn's disease activity index (CDAI), hemoglobin, white blood cells count, and erythrocyte sedimentation rate) was independently associated with clinical outcome. The procedure was well tolerated with no significant adverse effects registered.

Can calprotectin predict relapse risk in inflammatory bowel disease?

OBJECTIVE: Assessing the clinical course of inflammatory bowel disease (IBD) patients consists of periodical clinical evaluations and laboratory tests. We aimed to assess the role of calprotectin tests in predicting clinical relapse in IBD patients. METHODS: Ninety-seven patients with ulcerative colitis (UC) and 65 with Crohn's disease (CD) in clinical remission were prospectively included in the study. A 10-g stool sample was collected for calprotectin assay. The cutoff level was set at 130 mg/kg of feces. Patients were followed up for 1 yr after the test or until relapse. The cumulative proportion of relapses was estimated by the Kaplan-Meier analysis. Statistics for equality of survival distribution were tested using the log-rank test. RESULTS: The calprotectin test was positive in 44 UC patients and 26 of them relapsed within a year, while 11 of 53 UC patients with a negative calprotectin test relapsed within the same time frame. Thirty CD patients had a positive calprotectin test and 13 of them relapsed within a year, as did 7 of the 35 with a negative test result. A significant correlation emerged between a positive calprotectin test and the probability of relapse in UC patients (P= 0.000). In CD patients, only cases of colonic CD showed a significant correlation between a positive calprotectin test and the probability of relapse, i.e., 6 colonic CD patients were positive for the calprotectin test and 4 relapsed (P= 0.02). CONCLUSIONS: Measuring calprotectin may help to identify UC and colonic CD patients at higher risk of clinical relapse.

Effect of penicillamine and zinc on iron metabolism in Wilson's disease.

OBJECTIVE: The physiology of iron metabolism in Wilson's disease is largely unknown, and there is a paucity of data on the real presence and progression of iron accumulation. The purpose of this study was to assess the iron metabolism parameters, including hepatic iron concentration, in follow-up liver biopsies and serum, and urinary pro-hepcidin. MATERIAL AND METHODS: Twenty-three Wilson's disease patients undergoing long-term treatment were enrolled in the study. RESULTS: Hepatic iron content was significantly increased in penicillamine-treated patients compared with zinc-treated patients. Serum and urinary pro-hepcidin concentrations were significantly higher in Wilson's disease patients than in healthy volunteers, despite a normal biochemical pattern of iron metabolism. CONCLUSIONS: Long-term penicillamine treatment seems to be responsible for a more marked iron accumulation in the liver. This observation may justify a revision of long-term Wilson's disease treatment modalities with penicillamine. The finding that serum and urinary pro-hepcidin is significantly increased in Wilson's disease patients compared with healthy volunteers suggests a role for hepcidin in iron metabolism in Wilson's disease, but this needs to be confirmed by a study of hepatic hepcidin expression in these patients.

Calprotectin and lactoferrin in the assessment of intestinal inflammation and organic disease.

BACKGROUND AND AIMS: Calprotectin and lactoferrin are specific neutrophil-derived proteins, which can be measured in the feces because they are released by cells in inflammatory conditions. We evaluated the efficacy of calprotectin and lactoferrin in detecting organic disease as assessed by colonoscopy. METHODS: The study comprised 144 patients undergoing colonoscopy for lower gastrointestinal symptoms (abdominal pain, altered bowel habits, and bloody stools) (67), or inflammatory bowel disease activity, or surveillance for dysplasia (77). A single stool sample was assayed for calprotectin and lactoferrin. The proportion of patients correctly diagnosed with each test and the relationship with endoscopic and histological findings were measured. RESULTS: Fecal excretion of calprotectin significantly correlated with the finding of colonic inflammation at endoscopy, both in ulcerative colitis and in Crohn's disease (p<0,001 and p<0,008, respectively), while lactoferrin excretion significantly correlated with histological inflammation (p=0.001 and p=0.009 respectively). Recommended cut-off values need to be adjusted in the inflammatory bowel disease group. Overall sensitivity, specificity, positive predictive value, and diagnostic efficacy were 78, 83, 86, and 80% for calprotectin and 80, 85, 87, and 81% for lactoferrin, respectively. CONCLUSIONS: Fecal calprotectin and lactoferrin appear to be equally recommendable as inflammatory disease markers in patients with lower gastrointestinal symptoms. Both tests are needed to accurately discriminate activity in inflammatory bowel disease patients.

Increased intestinal permeability in obese mice: new evidence in the pathogenesis of nonalcoholic steatohepatitis.

A small percentage of pathologically obese subjects with fatty livers develop histological signs of necroinflammation and fibrosis, suggesting a variety of cofactors in the pathogenesis of obesity-related liver diseases including nonalcoholic steatohepatitis. Since several observations have linked bacterial endotoxins to liver damage, the aim of this study was to determine the effect of obesity on intestinal mucosal integrity and portal blood endotoxemia in two strains of obese mice: leptin-deficient (ob/ob) and hyperleptinemic (db/db) mice. Murine intestinal mucosal barrier function was assessed using a Ussing chamber, whereas ileum tight junction proteins were analyzed by immunocytochemistry and Western blot analysis. Circulating proinflammatory cytokines and portal blood endotoxin levels were measured by ELISA and the limulus test, respectively. The inflammatory and fibrogenic phenotype of murine hepatic stellate cells (HSCs) was determined by ELISA and quantitative RT-PCR. Ob/ob and db/db mice showed lower intestinal resistance, profoundly modified distribution of occludin and zonula occludens-1 in the intestinal mucosa, and higher circulating levels of inflammatory cytokines and portal endotoxemia compared with lean control mice. Moreover, HSCs isolated from ob/ob and db/db mice showed higher membrane CD14 mRNA levels and more pronounced lipopolysaccharide-induced proinflammatory and fibrogenic responses than HSCs from lean animals. In conclusion, genetically obese mice display enhanced intestinal permeability leading to increased portal endotoxemia that makes HSCs more sensitive to bacterial endotoxins. We suggest that in metabolic syndrome, patients may likewise have a greater intestinal mucosa permeability and increased lipopolysaccharide levels in portal blood that can contribute to the liver inflammatory damage.

Phosphatidylinositol 3'-kinase is a critical mediator of interferon-gamma-induced increases in enteric epithelial permeability.

The epithelial lining of mucosal surfaces acts as a barrier to regulate the entry of antigen and pathogens. Nowhere is this function of the contiguous epithelium more important than in the gut, which is continually exposed to a huge antigenic load and, in the colon, an immense commensal microbiota. We assessed the intracellular signaling events that underlie interferon (IFN) gamma-induced increases in epithelial permeability using monolayers of the human colonic T84 epithelial cell line. Confluent epithelial monolayers on semipermeable supports were treated with IFNgamma (20 ng/ml), and barrier function was assessed 48 h later by measuring transepithelial electrical resistance (TER: reflects passive ion flux), fluxes of (51)Cr-EDTA and horseradish peroxidase (HRP), and transcytosis of noninvasive, nonpathogenic Escherichia coli (strain HB101). Exposure to IFNgamma decreased barrier function as assessed by all four markers. The phosphatidylinositol 3'-kinase (PI-3K) inhibitors, LY294002 [2-(4-morpholinyl)-8-phenyl-1(4H)-benzopyran-4-one hydrochloride] and wortmannin, did not affect baseline permeability characteristics but completely blocked the drop in TER, increased fluxes of (51)Cr-EDTA and HRP, and significantly reduced E. coli transcytosis evoked by IFNgamma. In addition, use of the pan-protein kinase C (PKC) inhibitor, bisindolylmaleimide I (5 muM), but not rottlerin (blocks PKCdelta), partially ameliorated the drop in TER and inhibited increased E. coli transcytosis. Addition of the PI-3K and PKC inhibitors to epithelia 6 h after IFNgamma exposure still prevented the increase in paracellular permeability but not E. coli transcytosis. Thus, IFNgamma-induced increases in epithelial paracellular and transcellular permeability are critically dependent on PI-3K activity, which may represent an epithelial-specific target to treat immune-mediated loss of barrier function.

Small bowel exploration by wireless capsule endoscopy: results from 314 procedures.

OBJECTIVES: To assess the diagnostic efficiency of capsule endoscopy in a large group of patients with different indications, to weigh the reliability of the procedure for excluding small bowel lesions, and to identify factors associated with the likelihood of obtaining a definitive diagnosis. METHODS: Three hundred four consecutive patients (141 female, mean age 55 years, range 12-91 years) underwent capsule endoscopy in two different Gastroenterology Units, for a total of 314 procedures, and were followed-up for a median period of 15 months. Referrals were obscure occult/overt gastrointestinal bleeding (203 patients), suspected small bowel disease (74), gastrointestinal polyposis (18), suspected/previous intestinal or endocrine malignancies (13), previously diagnosed intestinal lymphangectasia (3), and vascular abnormalities (3). RESULTS: Adequate visualization of the small bowel was obtained in 96% of patients, although the capsule did not visualize cecum in 20% of cases. Non-natural excretion of the capsule was observed in 4 patients, all of whom underwent laparotomy for intestinal stenosis. Diagnostic yields were 58% for obscure gastrointestinal bleeding and 31% for patients with suspected small bowel disease. Capsule endoscopy was able to rule out small bowel disease in 14% of patients, and a definitive diagnosis was achieved in 65% of patients. The only parameter associated with the likelihood of reaching a conclusive diagnosis was the indication to the procedure (overall chi-square 13.5, P = .004). CONCLUSIONS: Capsule endoscopy represents a reliable tool for verifying the state of the small bowel. Accurate selection of indications and critical evaluation of the results are essential to fully exploit this procedure.

CD23-mediated IgE transport across human intestinal epithelium: inhibition by blocking sites of translation or binding.

BACKGROUND & AIMS: In previous studies in rodent models of food allergy, we identified that sensitization induces expression of CD23 on intestinal epithelial cells and results in enhanced IgE-dependent transepithelial antigen uptake; further studies in CD23-/- mice provided evidence that CD23 is involved in protected transport of antigen into the body. Little information exists in humans on receptor-mediated immunoglobulin (Ig)E transport across epithelia. The present study was designed to examine expression of CD23 by human epithelial cells, determine its isoform and regulation by interleukin (IL) 4, and identify the role of CD23 in transepithelial IgE transport. METHODS: Epithelial expression of CD23 was studied in cell lines, ileal biopsy specimens, and explanted fetal intestine. Bidirectional transport of IgE was measured across filter-grown cells, either normal cells or those transfected with antisense CD23 oligonucleotides, or in the presence of blocking antibody. RESULTS: Expression of the low-affinity IgE receptor was demonstrated in cultured epithelial cells as well as in situ cells in human intestine. CD23b was the isoform expressed by HT29, T84, and Caco-2 cells. IL-4 up-regulated the expression of epithelial CD23. IgE was transported in both the basal-to-apical direction and the apical-to-basal direction across filter-grown epithelial cells, a process that was inhibited by transfection of cells with CD23 antisense oligonucleotides or pretreatment with nonspecific IgE or anti-CD23 antibody. CONCLUSIONS: These findings provide evidence that CD23 encodes a functional IgE receptor on human intestinal epithelial cells and that this epithelial receptor is likely to play an important role in food allergies.

Clinical relevance of small-bowel findings detected by wireless capsule endoscopy.

OBJECTIVE: Capsule endoscopy is becoming known as a valid tool for identifying sources of obscure gastrointestinal (GI) bleeding. Fewer data are available about its clinical value for other indications. MATERIAL AND METHODS: Sixty patients (31 F, mean age 47 years, range 14-80 years) with no signs of overt GI bleeding were investigated by Given M2A video capsule for suspected small-bowel disease. The main clinical features were: iron deficient anemia (20), abdominal pain (12), chronic diarrhea (9), malabsorption and weight loss (7), Crohn's disease (CD) (5), and familial adenomatous polyposis (3). Three patients underwent wireless endoscopy for suspected GI neoplasm and one for portal thrombosis. RESULTS: Complete vision of the small bowel was achieved in 55 patients. No small-bowel lesions were identified in 17 patients, but 5 of them had gastric abnormalities. Small-bowel abnormality was found in 38 patients. Lesions compatible with CD were found in 14 patients, diffuse or patchy enteropathy in 7 and polyps in 6. Actively bleeding lesions were detected in 6 patients and potential bleeding sources in 5. Capsule endoscopy had an overall diagnostic yield of 62%. In particular, three small-bowel malignancies were detected and 9 patients received a better definition of their already-known pathology. However, further endoscopies were needed in 10 patients to obtain a diagnosis. One patient, diagnosed with ileal CD, underwent surgery, as the capsule remained trapped in a stricture. CONCLUSIONS: Wireless endoscopy effectively visualizes small-bowel abnormalities even though more accurate selection of the patients is needed in order to optimize its diagnostic efficacy.

Effect of Helicobacter pylori and eradication therapy on gastrointestinal permeability. Implications for patients with seronegative spondyloarthritis.

OBJECTIVE: Disruption of intestinal barrier function, followed by increased antigen load, may possibly trigger joint inflammation. In seronegative spondyloarthritis (SpA) both gut inflammation and altered intestinal permeability have been reported. We evaluated the influence of Helicobacter pylori and nonsteroidal antiinflammatory drugs (NSAID) on gastrointestinal (GI) permeability in SpA. Twenty SpA patients (7 women, mean age 47 +/- 13 SD yrs), 30 patients with endoscopic gastritis (EndG; 17 women, mean age 48 +/- 14 yrs), and 35 healthy controls (16 women, mean age 40 +/- 15 yrs) were studied. No patient was undergoing antisecretory therapy. In the SpA group, 8 patients were chronically taking NSAID and 12 took NSAID occasionally, none during the month before the study. All subjects were assessed for gastroduodenal (sucrose) and intestinal (lactulose/mannitol) permeability test and H. pylori status (urea breath test). RESULTS: H. pylori affected GI permeability in both SpA and EndG patients. After eradication therapy, sucrose excretion remained increased in SpA and reverted to normal in EndG patients, whereas lactulose/mannitol test became comparable to controls in both groups. SpA patients taking chronic NSAID had increased gastroduodenal permeability only when H. pylori-positive. In SpA patients, GI permeability did not correlate with clinical activity or biochemical inflammation. CONCLUSION: In SpA, H. pylori and NSAID contribute to impaired GI permeability. Eradication therapy may help to maintain epithelial barrier function and possibly influence clinical improvement in patients with SpA.

Lactulose/mannitol test has high efficacy for excluding organic causes of chronic diarrhea.

OBJECTIVES: Diagnosis in chronic diarrhea in the absence of a distinctive clinical pattern is often challenging, as biochemical tests prescribed at the first evaluation do not show enough sensitivity and specificity to tailor further investigation. Intestinal permeability to sugars is an accurate test for detecting intestinal damage. The aim of this study was to evaluate the diagnostic value of the lactulose/mannitol (L/M) test in patients with chronic diarrhea. METHODS: We conducted a prospective cohort study to evaluate the diagnostic value of the L/M test in chronic diarrhea. The test was administered to 261 consecutive patients presenting with three or more bowel movements daily for at least 3 wk. Biochemical tests including complete blood cell count, acute phase reactive proteins, serum albumin and iron, and stool cultures for bacteria, ova, and parasites were assessed at the same time. Additional diagnostic investigations were directed by clinical features as well as first-line test results. RESULTS: Over 3 yr, 120 (46%) of our patients were found to have an organic cause for chronic diarrhea, whereas in 141 (54%) a functional condition was diagnosed. Multivariate logistic regression analysis revealed that the L/M test and C-reactive protein were independent predictors for the final diagnosis of organic cause of chronic diarrhea, with odds ratios of 1.5 (95% CI = 1.29-1.78) and 5.2 (95% CI = 1.90-14.12), respectively. The area under the receiver operating characteristic (ROC) curve of the adjusted model was 0.82, with positive predictive value of 80.4% and negative predictive value of 77.7%. CONCLUSIONS: The L/M test is a powerful tool for workup in patients with chronic diarrhea. Introducing the L/M test as first-level test effectively improves the selection of patients who need further evaluation.

Gastroduodenal and intestinal permeability in primary biliary cirrhosis.

OBJECTIVES: To evaluate gastrointestinal permeability in primary biliary cirrhosis (PBC), using a sensitive method to detect epithelial damage, and to correlate it with the Mayo score, histological stage, ascites, spontaneous bacterial peritonitis, endoscopic signs of portal hypertension and Helicobacter pylori infection. METHODS: Fifty consecutive patients with PBC and 39 patients with cirrhosis of other aetiologies (non-PBC) were enrolled in the study. Coeliac disease was initially ruled out in all participants. Permeability was assessed using sucrose (gastro-duodenum) and lactulose-mannitol (intestine). RESULTS: Sucrose excretion was above the limit in both PBC and non-PBC patients. Twenty-two per cent of PBC patients had an increased result for the lactulose-mannitol test compared to 12.8% of non-PBC cirrhotic patients. PBC patients had high sucrose excretion levels irrespective of the presence of any oesophageal varices, which significantly increased the gastroduodenal permeability in non-PBC patients only when associated with hypertensive gastropathy. Sucrose excretion was significantly enhanced by hypertensive gastropathy in non-PBC patients (P < 0.001) but not in PBC patients. No significant correlation was found in either group between gastrointestinal permeability and the other parameters. CONCLUSIONS: Gastrointestinal permeability is increased in PBC. Portal hypertension contributes to altered gastric mucosal permeability in non-PBC cirrhosis, whereas different epithelial dysfunction can be hypothesized in PBC.

Factors regulating the effect of IL-4 on intestinal epithelial barrier function.

BACKGROUND: Inflammatory bowel disease is associated with an imbalance in cytokine production and defective intestinal barrier function. Previous studies indicate that IL-4, a cytokine increased in food allergy and in early Crohn's disease, enhances epithelial permeability. Here, we characterized the mechanism of action of IL-4 on cultured epithelial cells and examined if the anti-inflammatory cytokines, TGF-beta or IL-10, can modulate the effects of IL-4. METHODS: Confluent monolayers of human T84 epithelial cells were cultured with IL-4 alone or in combination with IL-10 or TGF-beta or with inhibitors of protein synthesis and blockers of IL-4 receptor signalling pathways. Permeability was evaluated by measuring transepithelial resistance (TER), flux of (3)H-fMLP (a small bacterial tripeptide) and horseradish peroxidase (HRP) (a macromolecule). RESULTS: T84 cells cultured with IL-4 showed a significant drop in TER as well as an increased flux of (3)H-fMLP and HRP. Co-treatment with IL-10 did not improve TER, whereas TGF-beta attenuated the resistance drop. However, neither TGF-beta nor IL-10 were able to correct the increased (3)H-fMLP flux. In contrast, the increased HRP flux caused by IL-4 was inhibited by both IL-10 and TGF-beta. TGF-beta and IL-10 significantly reduced IL-4-enhanced values for endosomal area and paracellular spaces containing HRP. Inhibitor studies indicated the requirement for protein synthesis and the involvement of phosphatidylinositol 3-kinase. CONCLUSIONS: These results provide new insights into the regulation of intestinal barrier function and may suggest a novel approach in the treatment of intestinal inflammation.

Effect of zinc supplementation on intestinal permeability in experimental colitis.

Increased small-intestine permeability has been documented in experimental colitis in the rat. Zinc supplementation improves mucosal repair in patients with diarrhea, as well as paracellular permeability in malnourished guinea pigs. In this study, we sought to evaluate the effect of zinc supplementation on small-and large-intestine tight junctions in rats with acute colitis. Rats were given zinc at a dosage of 2 or 30 mg/kg body wt or glucose by gavage starting 3 days before colitis was induced through the intrarectal administration of dinitro-benzene-sulfonic acid and for 7 days thereafter. We evaluated small-intestine permeability by the number of tight junctions showing extravasation of lanthanum under electron microscopy. Low-dose zinc affected none of the examined parameters of colitis severity. Rats given high-dose zinc showed colitis of similar macroscopic and biochemical severity. However, zinc-treated rats weighed more than unsupplemented ones. The number of perfused tight-junction complexes was significantly higher in animals with colitis than in controls and in the rats with colitis given high-dose zinc. Zinc may regulate tight-junction permeability, with possible implications for healing processes in inflammatory bowel diseases.