R. Carratù

Zonulin Upregulation Is Associated With Increased Gut Permeability in Subjects With Type 1 Diabetes and Their Relatives

Zonulin, a protein that modulates intestinal permeability, is upregulated in several autoimmune diseases and is involved in the pathogenesis of autoimmune diabetes in the BB/Wor animal model of the disease. To verify the association between serum zonulin levels and in vivo intestinal permeability in patients with type 1 diabetes, both parameters were investigated in different stages of the autoimmune process. Forty-two percent (141 of 339) of the patients had abnormal serum zonulin levels, as compared with age-matched control subjects. The increased zonulin levels correlated with increased intestinal permeability in vivo and changes in claudin-1, claudin-2, and myosin IXB genes expression, while no changes were detected in ZO1 and occludin genes expression. When tested in serum samples collected during the pre–type 1 diabetes phase, elevated serum zonulin was detected in 70% of subjects and preceded by 3.5 ± 0.9 years the onset of the disease in those patients who went on to develop type 1 diabetes. Combined, these results suggest that zonulin upregulation is associated with increased intestinal permeability in a subgroup of type 1 diabetic patients. Zonulin upregulation seems to precede the onset of the disease, providing a possible link between increased intestinal permeability, environmental exposure to non–self antigens, and the development of autoimmunity in genetically susceptible individuals.

Intestinal permeability in Crohn's disease patients and their first degree relatives.

BACKGROUND Family studies suggested that an altered intestinal permeability plays a role in the genesis of Crohns disease. AIM Aim of the present study was to investigate a possible genetic alteration of the mucosal barrier in Crohns disease. SUBJECTS 16 Crohns disease patients and 26 of their cohabiting first degree relatives were studied. METHODS To investigate intestinal permeability, Cellobiose/Mannitol test was administered to both groups. RESULTS In the two groups, we found that the median intestinal permeability values were higher and statistically different from those obtained in 32 healthy control subjects as well as in five healthy control families. Six (37.5%) Crohns disease patients and three (11.5%) of their first degree relatives showed increased individual intestinal permeability values. Intestinal permeability alteration in Crohns disease patients was unrelated to sex, age, disease activity, localisation, duration, treatment schedule, as well as to serum anti-Saccharomyces cervisiae antibody positivity in a pilot study conducted in 7 Crohns disease patients; anti-Saccharomyces cervisiae antibody values were negative in all 10 first degree relatives investigated. CONCLUSIONS These findings demonstrate the increase in IP in 37% of the patients and in 11% of their relatives. More extensive investigation of the correlation between ASCA alterations and IP will be needed in both patients with Crohns disease and their relatives.

Effect of chemotherapy with 5-fluorouracil on intestinal permeability and absorption in patients with advanced colorectal cancer.

5-Fluorouracil (5-FU), in association with leucovorin (LV), is the most used chemotherapy agent in the treatment of colorectal cancer. Response rate, as well as side-effect incidence, increases with the dose intensity of regimens that are used. The most common dose-limiting toxicity for 5-FU/LV modulation is diarrhea. To assess the modification of small intestinal function, we investigated the changes in intestinal permeability (IP) and intestinal absorption (IA) in 41 chemo-naive patients (21 men and 22 women; mean age, 61 ± 9 years) with advanced colorectal cancer after treatment with the association of folinic acid and 5-FU. After chemotherapy administration, we found a marked increase in IP and a reduction in IA, measured as cellobiose–mannitol (CE–MA) ratio (p < 0.0001) and D-xylose absorption (p = 0.0001), respectively. Patients who experienced diarrhea have an increase in CE–MA ratio and a reduction in D-xylose absorption values, both statistically significant. Cellobiose–mannitol ratio and D-xylose absorption tests can be used for the assessment of toxic effect of 5-FU on mature intestinal epithelium and also for evaluating the role of cytoprotective agents.

Cellobiose and lactulose coupled with mannitol and determined using ion-exchange chromatography with pulsed amperometric detection, are reliable probes for investigation of intestinal permeability

Lactulose/mannitol and cellobiose/mannitol tests are currently used in the investigation of intestinal permeability (IP) in many gastrointestinal diseases. The aim of this study was to produce a good technique for the determination and comparison of the above-mentioned sugar probes to overcome the problem caused by the presence of significant glycosuria in patients affected by particular metabolic disorders such as diabetes mellitus. Tests were performed in 25 healthy volunteers, using either cellobiose (Ce) (5 g) and mannitol (Ma) (2 g), or lactulose (La) (5 g) and mannitol (2 g), given as oral isosmolar loads. Sugars were recovered in urine collected for 5 h. Analysis was carried out by using anion-exchange chromatography (AEC) with pulsed amperometric detection (PAD). Baseline separation of the above carbohydrates was achieved within 13 min by using a Carbopac PA-100 column and linear gradient elution. Carbohydrate quantification was performed by an internal standard method. The calibration curve for each sugar is linear to 40 mM. The limit of sugar detection is 0.01 mM. Recovery of sugar probes is between 98.2 and 100%. The %La, %Ce, %Ma in urine were evaluated and their ratios (Ce/Ma and La/Ma) were calculated. No significant difference in IP parameters were shown (La/Ma to Ce/Ma 0.018+/-0.014 vs. 0.012+/-0.007; the attendant probability of the null hypothesis being P=0.0714). Ce/Ma and/or La/Ma tests result similarly reliable in the clinical investigation of IP and the described new method is also helpful in urine even with high glucose concentration, without any interference.

Age-Related Clinical Severity at Diagnosis in 1705 Patients with Ulcerative Colitis

Clinical–endoscopic parameters of UC presentation were studied in 1705 out-patients, observed consecutively in 17 Italian gastroenterology centers (males 60.2%; average age at diagnosis 38.5 ± 16.4 years), and were subdivided arbitrarily into quartile age groups at diagnosis (0–25, 26–35, 36–50, >50). A significantly greater prevalence in males, increasing with age, was shown at diagnosis (P = 0.0002), which seems to correlate with the condition of being an ex-smoker, most frequently found in males. The greater frequency of exsmokers could also, in part, justify the second peak of incidence in old age. Greater colitis extent, greater clinical activity, and greater use of steroids as the first therapeutic step are shown to prevail among younger patients and among women (P = 0.02 and P = 0.019, respectively). The same is observed for symptoms mainly representing clinical severity such as diarrhea, fever, and weight loss (P = 0.004; P = 0.006; P = 0.009, respectively). This study confirms the UC risk factor represented by the condition of being an ex-smoker and shows a greater severity of illness on diagnosis in younger patients.

Assessment of intestinal permeability and orocecal transit time in patients with systemic sclerosis: analysis of relationships with epidemiologic and clinical parameters

ObjectiveThe aim of this study was to assess intestinal permeability (IP) in patients with systemic sclerosis (SSc) and to relate the results with general disease activity and gastrointestinal involvement.MethodsTwenty-eight females and four males were studied. Patients with severe gastrointestinal involvement were excluded. Thirty-three healthy volunteers served as controls. Intestinal permeability was assessed by means of the orally administered cellobiose/mannitol sugar (Ce/Ma) test. Intestinal transit time (ITT) was investigated with the H2-lactulose breath test.ResultsThe mean value of IP in 32 SSc patients was significantly higher than in 33 controls (P<0.05), although it fell within the normal range. Eleven patients showed abnormally high individual IP values (>0.028) that significantly correlated to disease duration (r=0.73). Altered IP was associated with the higher but not statistically relevant presence of anti-Scl70 antibodies (9/11) and to more severe gastrointestinal involvement. More than half of the SSc patients showed slower orocecal transit times on the H2 breath test. In particular, delayed ITT was observed in 60% of patients with increased IP and in all patients with moderate gastrointestinal involvement according to the scleroderma severity scale.ConclusionIntestinal permeability was altered in 11/32 SSc patients. Correlations between increased IP and duration of disease and degree of gastgrointestinal involvement appear to support the hypothesis of secondary involvement of the intestinal barrier, and the presence of anti-Scl70 antibodies in 82% of the patients with higher IP clearly reinforces the hypothesis of an altered immune response in these subjects.

Clinical evolution in an outpatient series with indeterminate colitis

PURPOSE: Diagnosis of indeterminate colitis, which is mainly based on histologic criteria, could represent either an interlocutory or a definite classification within inflammatory bowel diseases. A later evaluation could allow elimination of cases with transient attacks of colitis and the eventual change of diagnosis to that of ulcerative colitis (UC) or Crohns disease of the colon in some other patients. METHODS: A clinical follow-up study for a mean of 64 months was performed in 37 patients with inflammatory bowel disease with an initial diagnosis of indeterminate colitis. RESULTS: At the end of the follow-up period, 21 patients complained of persistent symptoms, and in 13 of these patients, endoscopic and histologic evolution of colitis was controlled. In four patients with initially a normal endoscopy, the pattern of normality was confirmed also on a histologic basis at the end of the follow-up. In seven of the remaining nine patients with an initial UC-like endoscopic picture, the UC diagnosis was made eventually also on a histologic basis. CONCLUSIONS: A closer monitoring, as with UC patients, could be recommended only in moderate patients with indeterminate colitis, with an initial UC-like endoscopic picture.

Effect of somatostatin on gastrin, insulin and glucagon secretion in two patients with Zollinger-Ellison syndrome

The somatostatin effects on insulin, glucagon and gastrin secretion were studied in 2 Zollinger-Ellison patients in basal conditionsand afterstimuli: secretin (SE) and bombesin (BBS). Fasting gastrin, glucagon and insulin levels were markedly reduced by somatostatin. Gastrin and glucagon responses to SE and BBS were inhibited during somatostatin infusion; insulin was inhibited in one case. These results suggest a possible usefulness of somatostatin to diagnose and treat patients with Zollinger-Ellison syndrome.

Serum p53 antibodies in patients affected with ulcerative colitis

During tumor progression, theaccumulation in genetic alterations is a fundamental characteristic of malignant cells. p53 gene is frequently mutated in human tumor. Cellular accumulation of p53 protein can initiate an immune response with generation of circulating anti-p53 antibodies. Patients with ulcerative colitis have an increased risk of developing colorectal neoplasm and, among the different genes involved in carcinogenesis, p53 may play a key role. Sera and tissues from 97 patients (M = 53, F = 44) affected with ulcerative colitis (UC) were collected. Serum anti-p53 antibodies (p53Abs) were detected in duplicate with ELISA method. Serum p53Abs were detectable in 9.3% (9/97) of patients affected with UC. In these patients, the titer of p53Ab ranged between 3.1 and 14.9 U/mL (mean, 6.6 U/mL; SD, 4.64). Serum p53Abs were undetectable in control group. With an immunoluminometric assay for the quantitative determination of p53, we found 9/97 positive samples (≥0.69 mg/mg of total proteins). In contrast, the samples of the remaining 89 patients were found negative (≤0.30 mg/mg of total proteins). All patients that were positive for anti-p53 antibodies were also positive with p53 protein accumulation in the tissue of colonic biopsies. In UC, follow-up with colonoscopy has several advantages. The colonoscopy is not well accepted by patients, and poor patient observance has the potential to seriously devalue the technique as a screening tool, despite practical considerations of competence within endoscopy service. Serological detection of p53Abs by enzyme-linked immunosorbent assay (ELISA) is easy to perform, does not require tumor specimen, can be performed in a routine diagnostic procedure, may be used in clinical practice, and could facilitate physicians in patient monitoring. We suggest that serum p53Abs assessment, indirect marker for p53 gene mutations, and abnormally high p53 protein levels could be considered to have a potential for use as a complementary test to improve surveillance program performance.

Prevalence and relative risk of malignancy in relatives of inflammatory bowel disease patients and control subjects.

The relation between inflammatory bowel disease (IBD) and colorectal cancer (CRC) is not clearly defined. Some investigators suggest that patients with extensive colitis have a genetic predisposition to CRC and that long-standing inflammation is not of primary importance in the promotion of cancer. We have assessed any increased risk of colon cancer in the relatives of IBD patients. We studied the prevalence of malignancy in the relatives of 251 IBD patients [198 ulcerative colitis (UC); 53 Crohns disease of the colon (CDC)] and 251 orthopedic patients (ORTHO) as controls. In all patients (UC, CDC) as well as in controls (ORTHO) the prevalence of colon, extracolic digestive and extradigestive malignant tumors in the first-degree relatives was evaluated. We found no significant difference in the number of colorectal tumors or of tumors of any other kind in the diverse group of relatives of patients with IBD and ORTHO patients. Our data do not point to the existence of hereditary factors linking UC or CDC to CRC.