Neurological complications of celiac disease and autoimmune mechanisms: preliminary data of a prospective study in adult patients.

Antibodies to gangliosides and Purkinje cells have been reported in patients with celiac disease (CD) with neuropathy and ataxia, respectively. Whether these antibodies are pathogenic is not clear. The response of neurological symptoms and antibody titers to a gluten-free diet is still controversial. The objective of our study was to assess whether neurological manifestations in CD patients correlate with antibody titers and a gluten-free diet.Thirty-five CD patients (9 males, 26 females, mean age 37.1 +/- 12.6 yrs) were followed prospectively. At initial evaluation, 23 were on a gluten-free diet, 12 were not. At recruitment and during follow-up, patients underwent neurological and electrophysiological evaluation. IgG, IgM, and IgA anti-ganglioside antibodies were assayed by ELISA; anti-neuronal antibodies were assessed by immunohistochemistry and Western blot. Four patients, all males, had electrophysiological evidence of neuropathy; three had been on a gluten-free diet for several months, and one was newly diagnosed. One had reduced tendon reflexes; another complained of distal paresthesias. With regard to anti-ganglioside antibodies, three patients had a moderate increase in antibodies without symptoms or signs of neuropathy. No patients had ataxia or cerebellar dysfunction, although in four patients reactivity to neuronal antigens was found. In 17 patients, an electrophysiological follow-up (mean duration of follow-up, 9 months) showed no changes. In conclusion, the preliminary results of this prospective study indicate that neuropathy, usually subclinical, may accompany CD. Antibody titers do not seem to correlate with neurological symptoms/signs or diet. Ongoing follow-up will help confirm these data and clarify the role, if any, of antibodies in neurological involvement in CD.

Transcriptional downregulation of tight junction protein ZO-1 in active coeliac disease is reversed after a gluten-free diet.

UNLABELLED: Coeliac disease is an autoimmune enteropathy characterized by an enhanced permeability of the intestinal epithelial barrier. In epithelial cells paracellular permeability is regulated by intercellular tight junction. The cytoplasmic protein ZO-1 interacts directly with F-actin and plays a pivotal role in the structural and functional organization of tight junction. AIM: The aim of this study was to investigate the expression and localization of ZO-1 in the intestinal mucosa of coeliac patients. PATIENTS AND METHODS: Twenty patients with active coeliac disease, seven of whom underwent a repeat biopsy following a gluten-free diet and 27 control subjects, were studied. In all subjects, three biopsies were obtained from distal duodenum during upper gastrointestinal endoscopy. ZO-1 protein localization and levels were detected by immunofluorescence followed by confocal microscopy analysis and immunoblotting. ZO-1 mRNA expression was assessed by RT-PCR. F-actin distribution was also investigated. RESULTS: In patients with active coeliac disease, both ZO-1 protein levels and mRNA were clearly reduced. Cytoskeletal organization was disrupted with F-actin staining concentrated at the subcortical and basal surface regions. Abnormalities in ZO-1 expression and actin organization were reversed after a gluten-free diet. CONCLUSIONS: In active coeliac disease, ZO-1 protein expression is downregulated at the transcriptional level in association with F-actin redistribution. These changes are completely reversed after a gluten-free diet and could contribute to the increased intestinal paracellular permeability observed in this disorder.

Esophageal hyperalgesia in patients with ulcerative colitis: role of experimental stress.

OBJECTIVES: Intestinal inflammation is associated with enteric nervous system alterations, at both inflamed and noninflamed sites. The perception of stimuli from the GI tract is enhanced during inflammatory conditions, but it is unknown whether visceral hypersensitivity is limited to the inflamed area or diffuse throughout the entire GI tract. Moreover, although stress can reactivate inflammatory processes in the gut, it is unknown if this can alter perception from the GI tract. Our aim was to determine if patients with ulcerative colitis (UC) have increased esophageal sensitivity to distention and whether this is modified by experimental stress. METHODS: Ten UC patients and 12 healthy volunteers (HVs) underwent gradual balloon distension of the esophagus to assess their visceral sensitivity. Perceptive and pain thresholds were evaluated in basal conditions and after induction of experimental stress (cold water pressure test) while blood pressure and heart rate were monitored. RESULTS: Patients with UC had perceptive thresholds to distension similar to HVs (14.8+/-2.0 ml of air vs 14.5+/-3.0 ml); in contrast, the volume increment needed to evoke pain was significantly lower in UC patients than in HVs (58.9% vs 149.9%, p < 0.05). Physical stress caused a similar decrease in perceptive thresholds in HVs (-29.1+/-8.4%) and patients (-17.7+/-9.1%), but pain thresholds were significantly decreased only in HVs (-28.3+/-7.1% vs -11.5+/-12.3%). CONCLUSIONS: UC is characterized by increased esophageal sensitivity, indicating the existence of diffuse hyperalgesia during intestinal inflammatory processes. This increased sensitivity may account for the frequent upper GI symptoms these patients complain of when in clinical remission.

Zinc supplementation tightens "leaky gut" in Crohn's disease.

OBJECTIVES: Small intestinal permeability is often increased in patients with Crohn's disease and may be pathogenic for clinical relapses. No effective prophylactic treatment is available for these patients. The aim of this study was to ascertain whether zinc supplementation may improve intestinal permeability. METHODS: We studied 12 patients with quiescent Crohn's disease who had been in remission for at least 3 months and had increased intestinal permeability on two separate occasions within the last 2 months. Patients received oral zinc sulfate supplements (110 mg three times a day) for 8 weeks and were followed-up for 12 months thereafter to monitor relapses. RESULTS: We found that the lactulose/mannitol ratio was significantly higher before supplementation than after (0.041 +/- 0.003 versus 0.026 +/- 0.005). During follow-up, 10 patients had normal intestinal permeability and did not relapse; of the remaining two who had increased intestinal permeability, one relapsed. CONCLUSIONS: Our findings show that zinc supplementation can resolve permeability alterations in patients with Crohn's disease in remission. Improving intestinal barrier function may contribute to reduce the risk of relapse in Crohn's disease.

Reduced plasma antioxidant concentrations and increased oxidative DNA damage in inflammatory bowel disease.

BACKGROUND: Oxidative stress is believed to play a key role in the pathogenesis of inflammatory bowel disease (IBD)-related intestinal damage. Circulating antioxidants may have a role to play in preventing free radical-mediated tissue injury. METHODS: Plasma vitamin A, E and carotenoid concentrations, leukocytic genomic damage and 8-hydroxy-deoxy-guanosine (8-OHdG) concentration were determined in 46 ulcerative colitis (UC) patients, 37 Crohn disease (CD) patients and 386 controls. A 20 ml blood sample was taken from each subject for antioxidant and 8-OHdG measurements. A food frequency questionnaire was administered to a sample of subjects from each group to evaluate daily intake of dietary compounds. RESULTS: Antioxidant concentration was significantly reduced in IBD patients, particularly in those with active disease, with respect to controls (P < 0.0001). 8-OHdG concentrations were significantly increased in IBD patients compared to controls, independent of disease activity (P < 0.05). No correlation was found between antioxidant and 8-OHdG concentrations. Carotenoid concentrations were significantly reduced in malnourished IBD patients (0.89 +/- 0.14 micromol/l) compared to patients with normal or high body mass index (1.83 +/- 0.12 micromol/l; P < 0.05), independent of disease activity or extension. Protein, fruit and vegetable intakes of IBD patients were significantly lower than those of controls. CONCLUSIONS: Depletion of antioxidants is likely to be important in the pathophysiology of IBD: UC and CD patients show increased free radical peripheral leukocyte DNA damage and decreased plasma antioxidant defenses. These results indicate the necessity of further studies to establish whether optimal vitamin status may improve the clinical course of UC and CD.

High plasma levels of alpha- and beta-carotene are associated with a lower risk of atherosclerosis: results from the Bruneck study.

BACKGROUND AND PURPOSE: A large number of studies have contributed to the hypothesis that carotenoids, vitamins A and E are protective against atherosclerosis by acting as antioxidants. The aim of this study was to assess the relationship between plasma levels of carotenoids (alpha- and beta- carotene, lutein, lycopene, zeaxanthin, beta-cryptoxanthin), vitamins A and E, and atherosclerosis in the carotid and femoral arteries. METHODS: This prospective and cross sectional study involved a randomly selected population sample of 392 men and women aged 45-65 years. Carotid and femoral artery atherosclerosis was assessed by high-resolution duplex ultrasound. RESULTS: alpha- and beta- carotene plasma levels were inversely associated with the prevalence of atherosclerosis in the carotid and femoral arteries (P=0.004) and with the 5-year incidence of atherosclerotic lesions in the carotid arteries (P=0.04). These findings were obtained after adjustment for other cardiovascular risk factors (sex, age, LDL (low density lipoproteins), ferritin, systolic blood pressure, smoking, categories of alcohol consumption, social status, C-reactive protein). Atherosclerosis risk gradually decreased with increasing plasma alpha- and beta-carotene concentrations (P=0.004). No associations were found between vitamin A and E plasma levels and atherosclerosis. CONCLUSIONS: This study provides further epidemiological evidence of a protective role of high alpha- and beta- carotene in early atherogenesis.

Influence of disease site and activity on peripheral neutrophil function in inflammatory bowel disease.

Reactive oxygen species, released by phagocytes, are involved in tissue injury in inflammatory bowel diseases. The aim of our study was to evaluate peripheral neutrophil function in patients with ulcerative colitis (N = 66) and Crohn's disease (N = 62) with respect to disease activity and extent, using chemiluminometry after three stimuli. Twenty-seven healthy subjects were enrolled as controls. Neutrophils from ulcerative colitis and Crohn's disease patients had a significantly higher response than those from controls following phorbol myristate acetate (86.6 +/- 6.5, 173.8 +/- 11.9, 167.5 +/- 12.2 mV, P < 0.0001), formyl-methionyl-leucyl-phenylalanine (39.5 +/- 3.4, 41.3 +/- 2.7, 58.6 +/- 4.7 mV, P < 0.001), and zymosan (142.6 +/- 10.4, 223.7 +/- 8.9, 231.2 +/- 9.5 mV, P < 0.0001) administration. The increased response was observed during both active disease and remission. The highest chemiluminescence values were found in patients with active ulcerative pancolitis and ileal Crohn's disease. The activation of circulating neutrophils may indicate persistent intestinal inflammation or may be triggered by luminal factors even in the absence of symptoms.

Exercise and inflammatory bowel disease: immunological aspects.

Exercise may promote a healthy life, improving functional capacities. Little is known about the effects of physical activity in inflammatory bowel disease. Altered immunity is implicated in the pathogenesis of inflammatory bowel diseases. An acute, albeit transient acute immune response, follows heavy endurance exercise. Epidemiological data support the role of physical activity in lowering the risk of inflammatory bowel disease. Moderate physical exercise (60% VO2max) does not cause significant changes in symptoms, intestinal transit time, and permeability. Neutrophil function appears to be primed at basal conditions with significant activation after exercise. At present, mild exercise can be recommended to patients with quiescent inflammatory bowel disease as well as other chronic diseases such as rheumatoid arthritis, while caution is still needed for active disease patients. Patients with inflammatory bowel disease show a reduced exercise capacity after surgery, especially after extensive resections.

Plasma antioxidant levels in chronic cholestatic liver diseases.

BACKGROUND: [corrected] A predictable consequence of cholestasis is malabsorption of fat-soluble factors, (vitamins A, D, E, K) and other free radical scavengers, such as carotenoids. It has been suggested that oxygen-derived free radicals may be involved in the pathogenesis of chronic liver damage. AIMS: (i) To evaluate retinol, alpha-tocopherol and carotenoid plasma levels in two groups of patients with chronic cholestatic liver disease (primary biliary cirrhosis and primary sclerosing cholangitis); (ii) to compare the respective plasma levels with those of the general population; (iii) to correlate the plasma levels with disease severity. METHODS: A total of 105 patients with chronic cholestasis were included in the study: 86 with primary biliary cirrhosis (81 female, five male, mean age 55.5 +/- 11 years), 19 with primary sclerosing cholangitis (seven female, 12 male, mean age 35 +/- 11 years; six patients had associated inflammatory bowel disease); 105 sex- and age-matched subjects from the general population in the same geographical area (88 female, 17 male, mean age 51.3.5 +/- 10 years) served as controls. Carotenoids (lutein zeaxanthin, lycopene, beta-carotene, alpha-carotene, beta-cryptoxanthin), retinol and alpha-tocopherol were assayed by high-pressure liquid chromatography. A food frequency questionnaire was administered to each subject to evaluate the quality and the quantity of dietary compounds. Data were processed by analysis of variance and linear regression analysis, as appropriate. RESULTS: Both primary biliary cirrhosis and primary sclerosing cholangitis patients had significantly lower levels of retinol, alpha-tocopherol, total carotenoids, lutein, zeaxanthin, lycopene, alpha- and beta-carotene than controls (P < 0.0001). Among the cholestatic patients, no significant difference in the concentration of antioxidants was observed between primary biliary cirrhosis and primary sclerosing cholangitis subjects. Anti-oxidant plasma levels were not affected by the severity of the histological stage in primary biliary cirrhosis, but a negative correlation was found between total carotenoids and both alkaline phosphatase (ALP) and gammaglutamyl transpeptidase (GGT) (P < 0.013 and P < 0.018, respectively). Within the primary sclerosing cholangitis group, no correlation was found between total carotenoids and cholestatic enzymes. Nutritional intake in cholestatic patients was comparable to controls, including fruit and vegetable intake. CONCLUSIONS: Although no clinical sign of deficiency is evident, plasma levels of antioxidants are low in cholestatic patients even in early stages of the disease. This is probably due to malabsorption of fat-soluble vitamins, as well as other mechanisms of hepatic release, suggesting the need for dietary supplementation.

Intestinal permeability test as a predictor of clinical course in Crohn's disease.

OBJECTIVE: The clinical course of Crohn's disease is often unpredictable. The aim of this study was to select the most useful parameters able to predict clinical relapses. METHODS: One hundred-thirty Crohn's disease patients in clinical remission were followed every 4 months for 2 yr or until clinical relapse. Demographic and clinical data were recorded and intestinal permeability (lactulose/mannitol [L/M] test) and biochemical tests (white blood cell count, erythrocyte sedimentation rate, C-reactive protein, alpha1 acid glycoprotein, and serum iron) were performed at study entry. A subgroup of 54 patients had clinical follow-up and repeated tests every 4 months. RESULTS: Fifty-two patients (40%) relapsed during the 2-yr follow-up. A significant correlation was found between relapse and gender (p = 0.030) but not between relapse and age, extent and type of disease, previous surgery, or therapy. Increased L/M test (p = 0.0001) and decreased serum iron level (p = 0.0057) were associated with clinical relapse. Time-dependent analysis, performed on patients receiving serial evaluation, showed that L/M test alteration was the only variable that could predict a relapse (RR 8.84, 95% confidence interval [CI] 1.41-53.37; p < 0.05). CONCLUSIONS: The L/M test identifies Crohn's disease patients in apparent remission, but with a high risk of clinical relapse, better than clinical and biochemical indices. Different treatment strategies might be suggested for this subgroup of patients.

Oxygen-derived free radical production by peripheral blood neutrophils in chronic cholestatic liver diseases.

BACKGROUND/AIMS: Patients with chronic cholestasis, particularly those with associated cirrhosis, are susceptible to infectious complications. From animal models it has been postulated that cholestasis affects systemic polymorphonuclear leukocyte (PMNL) function by impeding chemotaxis, phagocytosis and superoxide release, which are necessary for an adequate immune response. The aim of this study was to evaluate neutrophil activity in the production of oxygen-derived free radicals in chronic cholestatic liver diseases. METHODOLOGY: The following groups were included in the study: 27 primary biliary cirrhosis (PBC) patients, 12 primary sclerosing cholangitis (PSC) patients, and 3 control groups (29 healthy subjects, 19 patients with HCV-related cirrhosis and 23 ulcerative colitis (UC) patients). Peripheral neutrophils were isolated from heparinized blood samples and PMNL activity was measured by free radical production, using a chemiluminometer, after stimulation with fMLP, PMA and Zymosan. The effect of liver disease severity and degree of cholestasis on PMNL function was also evaluated. RESULTS: Both PBC and PSC patients exhibited a normal PMNL activity compared to healthy subjects after the three stimuli used. In PBC patients only (but not in PSC patients), the histological stage of the disease seems to positively influence ROS production. Stage IV PBC patients showed a significantly higher PMNL activity compared to HCV-related cirrhotic patients. PSC patients failed to show any difference according to the association with UC. CONCLUSIONS: The increased susceptibility to bacterial infections in patients with chronic cholestatic liver disease is not related to an impaired PMNL activity. However, our findings may support the influence of biohumoral factors (cytokines?) on PMNL activation.

Effect of moderate exercise on Crohn's disease patients in remission.

BACKGROUND: Physical exercise may exacerbate the disturbed homeostasis of Crohn's disease patients. AIM: To examine the effect of moderate physical exercise on gastrointestinal function in a group of Crohn's disease patients in remission. PATIENTS AND METHODS: The effect of one-hour's exercise at a maximum of 60% oxygen consumption was evaluated in six males with ileal Crohn's disease in remission on orocaecal transit time (breath test to lactulose), intestinal permeability (6-hours' urinary excretion of a sugar mixture of lactulose/mannitol), polymorphonuclear leucocytes function (peripheral blood chemiluminescence), lipoperoxidation (plasma malondialdehyde) and antioxidant trace elements (urinary and plasma zinc and copper concentrations). Six healthy age-matched subjects served as controls. RESULTS: Exercise did not elicit subjective symptoms or changes in intestinal permeability and lipoperoxidation. Orocaecal transit time increased after exercise in Crohn's disease patients (72 min +/- 30 vs 100 min +/- 34) with no significant difference from controls (77 min +/- 20 vs 83 min +/- 23). Neutrophils, primed pre-exercise in Crohn's disease patients showed an increased post-exercise chemiluminescence similar to controls. Zinc urinary output significantly increased after exercise in Crohn's disease patients and remained unchanged in control subjects. CONCLUSIONS: Moderate aerobic exercise has no significant effect on the gastrointestinal parameters examined. However, basal neutrophil activation and exercise in Crohn's disease patients may trigger an excessive production of oxygen metabolites. Moreover, exercise may contribute to an increased risk of zinc deficiency.

Altered plasma and mucosal concentrations of trace elements and antioxidants in active ulcerative colitis.

BACKGROUND: The production of free radicals is increased in inflammatory bowel disease, and trace elements are crucial components of several antioxidants. Trace elements deficiency may therefore compromise the defense against oxidative damage. The aims of this study were to measure plasma and tissue concentration of trace elements and antioxidants and to relate this to disease activity. METHODS: A 10-ml blood sample and six colonic biopsy specimens were obtained from 24 patients with either active ulcerative colitis or in remission and 10 patients with irritable bowel syndrome for measurement of trace elements and trace element-dependent enzymes. RESULTS: Patients with moderately active disease had significantly lower plasma iron, selenium, and glutathione peroxidase levels than patients in remission and controls, whereas no significant differences were found between the zinc and copper values of patients and controls. Mucosal concentrations of zinc and metallothionein were reduced, whereas iron and glutathione peroxidase concentrations were increased in patients with endoscopically active disease as compared with controls and patients in remission. CONCLUSIONS: Patients with ulcerative colitis have altered plasma and tissue levels of trace elements and antioxidant-related enzymes. The resulting reduced protection against free radicals may contribute to the inflammatory process.

Hepatocyte tight-junctional permeability is increased in rat experimental colitis.

BACKGROUND & AIMS: Hepatobiliary complications occur in inflammatory bowel disease and may be caused by the translocation of intestinal toxins from portal blood into bile through leaky hepatocyte tight junctions. The role of tight junctions in the pathogenesis of hepatobiliary complications in experimental inflammatory bowel disease was investigated. METHODS: Colitis was induced in rats by intracolonic instillation of trinitrobenzene sulfonic acid. The function of hepatocellular tight junctions was evaluated in perfused livers by measuring early (paracellular) horseradish peroxidase excretion into the bile and by electron microscopy and semiquantitative analysis of lanthanum penetration through the tight junction and into bile canaliculi. Immunofluorescent localization of cingulin and ZO-1 was used to study the structure of hepatocyte junctions. RESULTS: Colitis was associated with increased serum bilirubin and bile acid concentrations, a 2.5-fold increase in paracellular biliary excretion of horseradish peroxidase, and a ninefold increase in lanthanum permeability. Liver histology and cingulin and ZO-1 localizations were similar to normal liver. CONCLUSIONS: Experimental colitis is associated with hepatobiliary complications and an increased hepatocyte tight junctional permeability to horseradish peroxidase and lanthanum. Subtle alterations in tight junction function may be involved in the pathogenesis of hepatobiliary injuries in inflammatory bowel disease.

Quinone-induced DNA single strand breaks in a human colon carcinoma cell line.

It has been demonstrated that synthetic quinones, such as menadione, cause DNA damage in different cell systems, possibly being mediated by free radicals generated during redox cycling. It has been suggested that the damage caused could be related to tumor induction in different sites. To our knowledge it has not yet been demonstrated that the natural quinones, vitamin K1 and K2, exert the same activity. Using a colon carcinoma cell line, HT-29, we examined the extent of DNA damage induced by menadione, vitamin K1 and K2. Menadione caused significant DNA damage at low concentrations (25-200 microM) with a linear correlation of r = 0.95. In the presence of dicoumarol, a DT-diaphorase inhibitor, the damage was detected at concentrations five times lower indicating that free radicals generated during the redox cycling play a key role. Neither vitamin K1, incorporated in micelles, nor K2 caused detectable single strand breaks with respect to the controls either in the presence or in absence of dicoumarol. Our results demonstrate that, despite their redox cycling properties, the natural forms of vitamin K do not cause DNA damage in HT-29 cells as menadione does in the experimental conditions used.

Taste alterations in liver cirrhosis: are they related to zinc deficiency?

Patients with chronic liver disease may have taste impairment and altered zinc metabolism. We evaluated Taste Detection Thresholds (TDTs) in 60 patients with liver cirrhosis and correlated the findings with disease severity and alcoholic etiology. Plasma zinc levels and urinary output were also measured. A placebo-controlled treatment trial with zinc sulphate was made in 15 patients with compensated cirrhosis in order to ascertain whether zinc deficiency caused taste alterations. Taste detection of salty, sweet and acid tastants was significantly impaired in all cirrhotic patients in comparison with normal subjects. TDTs were not influenced either by the etiology or the severity of the disease. All groups of patients had low plasma zinc levels and decompensated cirrhosis had a significantly increased urinary output of zinc. No correlation was found between taste acuity and plasma zinc levels when only cirrhotic patients were considered. The effect of zinc supplementation on TDTs did not appear to be inferior to that of the placebo. Our results indicate that taste impairment in cirrhotics is due to the disease process per se and not to zinc deficiency.

Inhibition of gastric acid secretion reduces zinc absorption in man.

Numerous factors seem to affect zinc absorption. Gastric acid secretion has been demonstrated to facilitate iron absorption. The zinc tolerance test (ZTT with ZnSO4 220 mg p.o.) was performed in 11 healthy volunteers to study the effects of administering the acid secretion inhibitor cimetidine (1 g/day p.o. for 3 days) and to evaluate the influence of HCl gastric secretion on zinc absorption in physiological conditions. Zinc absorption was reduced after cimetidine administration (p less than 0.005), suggesting that gastric pH influences zinc absorption. To rule out any direct effect of the drug on zinc absorption in five other healthy adults we further evaluated zinc absorption by using a different H2 antagonist (ranitidine 300 mg/day for 3 days and 300 mg before the test). Cimetidine was also tested in these subjects at half the dosage administered to the first group of subjects. Gastric acidity was monitored at 60-min intervals throughout the test via a nasogastric tube. The areas under the plasma concentration curves for zinc were significantly reduced after ranitidine (p less than 0.01), but not after cimetidine administration. Gastric acid was also reduced after ranitidine, but not after cimetidine (500 mg) administration, suggesting that gastric acid secretion plays a role in the regulation of zinc absorption in man.

Psychiatric diagnoses in ulcerative colitis. A controlled study.

Fifty patients with UC and 50 matched controls with urolithiasis were interviewed with the SADS (lifetime version) and completed the SCL-90. According to information given during the SADS, there was a history of psychiatric disturbance in 11 UC patients (22%) and 8 controls (16%). At the time of the interview a psychiatric disturbance was present in 31 UC patients (62%) and four controls (8%), the most frequent diagnoses in the former being minor depression and generalised anxiety disorder. Patients with UC scored significantly higher than the controls on all the different SCL-90 subscales.