Filling the gap: A thorough investigation for the genetic diagnosis of unsolved polyposis patients with monoallelic MUTYH pathogenic variants.

BACKGROUNDS: MUTYH-associated polyposis (MAP) is an autosomal recessive disease caused by biallelic pathogenic variants (PV) of the MUTYH gene. The aim of this study was to investigate the genetic causes of unexplained polyposis patients with monoallelic MUTYH PV. The analysis focused on 26 patients with suspected MAP, belonging to 23 families. Ten probands carried also one or more additional MUTYH variants of unknown significance. METHODS: Based on variant type and on the collected clinical and molecular data, these variants were reinterpreted by applying the ACMG/AMP rules. Moreover, supplementary analyses were carried out to investigate the presence of other variants and copy number variations in the coding and promoter regions of MUTYH, as well as other polyposis genes (APC, NTHL1, POLE, POLD1, MSH3, RNF43, and MCM9). RESULTS: We reclassified 4 out of 10 MUTYH variants as pathogenic or likely pathogenic, thus supporting the diagnosis of MAP in only four cases. Two other patients belonging to the same family showed a previously undetected deletion of the APC gene promoter. No PVs were found in the other investigated genes. However, 6 out of the 18 remaining families are still interesting MAP candidates, due to the co-presence of a class 3 MUTYH variant that could be reinterpreted in the next future. CONCLUSION: Several efforts are necessary to fully elucidate the genetic etiology of suspected MAP patients, especially those with the most severe polyposis/tumor phenotype. Clinical data, tumor molecular profile, family history, and polyposis inheritance mode may guide variant interpretation and address supplementary studies.

Incidence and distribution of coeliac disease in Campania (Italy): 2011-2013.

BACKGROUND: There exists a wide variation in the reported incidence of coeliac disease in recent decades. We aimed to evaluate the incidence rate of coeliac diagnoses performed in an Italian region, Campania, between 2011 and 2013 and its variation therein. METHODS: All coeliac diagnoses made from 2011 to 2013 and registered within the Campania coeliac disease register (CeliacDB) were identified. Incidence rates were analysed by sex, age and province of residence, with a Poisson model fitted to determine incidence rate ratios. RESULTS: We found 2049 coeliac disease diagnoses registered in the CeliacDB between 2011 and 2013; 1441 of these patients were female (70.4%) and 1059 were aged less than 19 years (51.7%). The overall incidence of coeliac disease in Campania was 11.8 per 100,000 person-years (95% CI 11.3-12.3) during the study period, with marked variation by age [27.4 per 100,000 person-years (95% CI 25.8-29.1) in children under 19 years of age and 7.3 per 100,000 (95% CI 6.8-7.8) in adults] and sex [16.1 per 100,000 person-years in females (95% CI 15.3-16.9) and 7.2 per 100,000 person-years in males (95% CI 6.6-7.8)]. Coeliac disease incidence was roughly similar in Naples, Salerno, Caserta and Avellino, but about half in Benevento. More than 80% of our study population was diagnosed by the combination of positive antitransglutaminase IgA and Marsh 3. More than half of the patients were symptomatic at the time of coeliac disease diagnosis (39.7% had a classical presentation and 21.1% a non-classical one according to the Oslo definition). CONCLUSIONS: Coeliac disease incidence was roughly similar among Campania provinces, except in Benevento where it was about half, probably due to less awareness of coeliac disease in this area. The incidence of coeliac disease in Campania appears to be lower than that reported by most of the previous literature, suggesting the necessity of new coeliac awareness programmes.

Anisakiasis and gastroallergic reactions associated with Anisakis pegreffii infection, Italy.

Human cases of gastric anisakiasis caused by the zoonotic parasite Anisakis pegreffii are increasing in Italy. The disease is caused by ingestion of larval nematodes in lightly cooked or raw seafood. Because symptoms are vague and serodiagnosis is difficult, the disease is often misdiagnosed and cases are understimated.

Risk factors for inflammatory bowel diseases according to the "hygiene hypothesis": a case-control, multi-centre, prospective study in Southern Italy.

BACKGROUND: Ulcerative colitis (UC) and Crohn's disease (CD) are inflammatory bowel diseases (IBD) of unknown aetiology. The 'hygiene hypothesis' (HH) suggests that several hygiene-related factors may have contributed to the increased incidence of IBD. The aim of the study was to evaluate risk factors for IBD related to HH in a cohort of IBD patients from the south of Italy. METHODS: We prospectively performed a one-year, questionnaire-based, case-control, multi-centre study focusing on the principal risk factors for IBD according to HH. We investigated the main surrogate markers of HH (helmintic infections and antibiotics in childhood; breastfeeding; family size/sibship;urban upbringing; personal and domestic hygiene in childhood) in UC and CD patients, in comparison with a control group of healthy subjects. In addition, the traditional risk factors for IBD were also recorded. RESULTS: The study population included 527 cases of UC, 468 CD and 562 controls. None of the surrogate risk factors of HH was significantly associated with IBD. On the contrary, the traditional risk factors confirmed their statistical significance in this IBD population. Familial aggregation: OR 4.07 for UC; OR 4.83 for CD; smoking: OR 0.38 for UC; OR 1.40 for CD; appendectomy: OR 0.28 for UC; OR 1.61 for CD. CONCLUSION: Even though risk factors associated to the HH have been proposed as a possible explanation for the increasing calendar trend of IBD incidence, their role does not appear to be statistically significant. Familial aggregation, smoking habits and appendectomy still remain the main risk factors associated with IBD.

Predicting mortality in non-variceal upper gastrointestinal bleeders: validation of the Italian PNED Score and Prospective Comparison with the Rockall Score.

OBJECTIVES: We sought (i) to validate a new prediction rule of mortality (Progetto Nazionale Emorragia Digestiva (PNED) score) on an independent population with non-variceal upper gastrointestinal bleeding (UGIB) and (ii) to compare the accuracy of the Italian PNED score vs. the Rockall score in predicting the risk of death. METHODS: We conducted prospective validation of analysis of consecutive patients with UGIB at 21 hospitals from 2007 to 2008. Outcome measure was 30-day mortality. All the variables used to calculate the Rockall score as well as those identified in the Italian predictive model were considered. Calibration of the model was tested using the chi2 goodness-of-fit and performance characteristics with receiver operating characteristic (ROC) analysis. The area under the ROC curve (AUC) was used to quantify the diagnostic accuracy of the two predictive models. RESULTS: Over a 16-month period, data on 1,360 patients were entered in a national database and analyzed. Peptic ulcer bleeding was recorded in 60.7% of cases. One or more comorbidities were present in 66% of patients. Endoscopic treatment was delivered in all high-risk patients followed by high-dose intravenous proton pump inhibitor in 95% of them. Sixty-six patients died (mortality 4.85%; 3.54-5.75). The PNED score showed a high discriminant capability and was significantly superior to the Rockall score in predicting the risk of death (AUC 0.81 (0.72-0.90) vs. 0.66 (0.60-0.72), P<0.000). Positive likelihood ratio for mortality in patients with a PNED risk score >8 was 16.05. CONCLUSIONS: The Italian 10-point score for the prediction of death was successfully validated in this independent population of patients with non-variceal gastrointestinal bleeding. The PNED score is accurate and superior to the Rockall score. Further external validation at the international level is needed.

Characterization of intestinal bacteria tightly bound to the human ileal epithelium.

In order to perform selective isolation of bacteria tightly bound to the human gut, ileal biopsies of healthy volunteers were treated to wash out the mucus layer and loosely bound bacterial cells. Rod-shaped anaerobic bacteria that had remained attached to the epithelial cells were isolated and identified at the species level. One isolate was identified as belonging to the Bifidobacterium breve species, while all the others were lactobacilli of only two species, Lactobacillus mucosae and Lactobacillus gasseri. Members of these species were found previously in intestinal samples, but their predominance among bacteria strictly associated with the epithelium was not suspected before and suggests that these species may represent a specific subpopulation of tissue-bound bacteria. Physiological analysis indicated that all isolates were able to produce antimicrobials, grow and form biofilm in simulated intestinal fluid after exposure to gastric conditions. Some isolates were able to degrade mucin while none showed cytotoxicity in vitro on HT29 cells. The tight association of the strains isolated with ileal epithelial cells is presumably indicative of a direct interaction with the host cells. For this reason and for the absence of cytotoxicity in vitro, those isolates can be proposed as potential probiotic strains for human use.

Overactivity of the intestinal endocannabinoid system in celiac disease and in methotrexate-treated rats.

The endocannabinoid system is upregulated in both human inflammatory bowel diseases and experimental models of colitis. In this study, we investigated whether this upregulation is a marker also of celiac disease-induced atrophy. The levels of the cannabinoid CB(1) receptor, of the endocannabinoids, anandamide, and 2-arachidonoyl-glycerol (2-AG), and of the anti-inflammatory mediator palmitoylethanolamide (PEA) were analyzed in bioptic samples from the duodenal mucosa of celiac patients at first diagnosis assessed by the determination of antiendomysial antibodies and histological examination. Samples were analyzed during the active phase of atrophy and after remission and compared to control samples from non-celiac patients. The levels of anandamide and PEA were significantly elevated (approx. 2- and 1.8-fold, respectively) in active celiac patients and so were those of CB(1) receptors. Anandamide levels returned to normal after remission with a gluten-free diet. We also analyzed endocannabinoid and PEA levels in the jejunum of rats 2, 3, and 7 days after treatment with methotrexate, which causes inflammatory features (assessed by histopathological analyses and myeloperoxidase activity) similar to those of celiac patients. In both muscle/serosa and mucosa layers, the levels of anandamide, 2-AG, and PEA peaked 3 days after treatment and returned to basal levels at remission, 7 days after treatment. Thus, intestinal endocannabinoid levels peak with atrophy and regress with remission in both celiac patients and methotrexate-treated rats. The latter might be used as a model to study the role of the endocannabinoid system in celiac disease.

Up-regulation of anandamide levels as an endogenous mechanism and a pharmacological strategy to limit colon inflammation.

Direct stimulation of cannabinoid CB1 receptors exerts a protective function in animal models of inflammatory bowel diseases (IBDs). However, it is not known whether endocannabinoids are up-regulated during IBDs in animals or humans, nor whether pharmacological elevation of endocannabinoid levels can be exploited therapeutically in these disorders. In this study we addressed these questions. Colon inflammation was induced in mice and rats with 2,4-dinitrobenzene- and 2,4,6-trinitrobenzene sulfonic acids (DNBS and TNBS), respectively. DNBS-treated mice were treated chronically (for 3 or 7 days) with inhibitors of anandamide enzymatic hydrolysis (N-arachidonoyl-serotonin, AA-5-HT) or reuptake (VDM11), 10 or 5 mg/kg, s.c., or with 5-amino-salicilic acid (5-ASA, 1.4 mg/kg, i.r.). Endocannabinoids (anandamide and 2-arachidonoylglycerol, 2-AG) were quantified in mouse colon, or in rat colon mucosa and submucosa, and in bioptic samples from the colon of patients with untreated ulcerative colitis, by liquid chromatography-mass spectrometry. A strong elevation of anandamide, but not 2-AG, levels was found in the colon of DNBS-treated mice, in the colon submucosa of TNBS-treated rats, and in the biopsies of patients with ulcerative colitis. VDM-11 significantly elevated anandamide levels in the colon of DNBS-treated mice and concomitantly abolished inflammation, whereas AA-5-HT did not affect endocannabinoid levels and was significantly less efficacious at attenuating colitis. 5-ASA also increased anandamide levels and abolished colitis. Thus, anandamide is elevated in the inflamed colon of patients with ulcerative colitis, as well as in animal models of IBDs, to control inflammation, and elevation of its levels with inhibitors of its cellular reuptake might be used in the treatment of IBDs.

Involvement of the cannabimimetic compound, N-palmitoyl-ethanolamine, in inflammatory and neuropathic conditions: review of the available pre-clinical data, and first human studies.

The endogenous cannabimimetic compound, and anandamide analogue, N-palmitoyl-ethanolamine (PEA), was shown to exert potent anti-inflammatory and analgesic effects in experimental models of visceral, neuropathic and inflammatory pain by acting via several possible mechanisms. However, only scant data have been reported on the regulation of PEA levels during pathological conditions in animals or, particularly, humans. We review the current literature on PEA and report the results of three separate studies indicating that its concentrations are significantly increased during three different inflammatory and neuropathic conditions, two of which have been assessed in humans, and one in a mouse model. In patients affected with chronic low back pain, blood PEA levels were not significantly different from those of healthy volunteers, but were significantly and differentially increased (1.6-fold, P<0.01, N=10 per group) 30 min following an osteopathic manipulative treatment. In the second study, the paw skin levels of PEA in mice with streptozotocin-induced diabetic neuropathic pain were found to be significantly higher (1.5-fold, P<0.005, N=5) than those of control mice. In the third study, colonic PEA levels in biopsies from patients with ulcerative colitis were found to be 1.8-fold higher (P<0.05, N=8-10) than those in healthy subjects. These heterogeneous data, together with previous findings reviewed here, substantiate the hypothesis that PEA is an endogenous mediator whose levels are increased following neuroinflammatory or neuropathic conditions in both animals and humans, possibly to exert a local anti-inflammatory and analgesic action.

Possible endocannabinoid control of colorectal cancer growth.

BACKGROUND & AIMS: The endocannabinoids anandamide and 2-arachidonoylglycerol (2-AG) inhibit cancer cell proliferation by acting at cannabinoid receptors (CBRs). We studied (1). the levels of endocannabinoids, cannabinoid CB(1) and CB(2) receptors, and fatty acid amide hydrolase (FAAH, which catalyzes endocannabinoid hydrolysis) in colorectal carcinomas (CRC), adenomatous polyps, and neighboring healthy mucosa; and (2). the effects of endocannabinoids, and of inhibitors of their inactivation, on human CRC cell proliferation. METHODS: Tissues were obtained from 21 patients by biopsy during colonoscopy. Endocannabinoids were measured by liquid chromatography-mass spectrometry (LC-MS). CB(1), CB(2), and FAAH expression were analyzed by RT-PCR and Western immunoblotting. CRC cell lines (CaCo-2 and DLD-1) were used to test antiproliferative effects. RESULTS: All tissues and cells analyzed contain anandamide, 2-AG, CBRs, and FAAH. The levels of the endocannabinoids are 3- and 2-fold higher in adenomas and CRCs than normal mucosa. Anandamide, 2-AG, and the CBR agonist HU-210 potently inhibit CaCo-2 cell proliferation. This effect is blocked by the CB(1) antagonist SR141716A, but not by the CB(2) antagonist SR144528, and is mimicked by CB(1)-selective, but not CB(2)-selective, agonists. In DLD-1 cells, both CB(1) and CB(2) receptors mediate inhibition of proliferation. Inhibitors of endocannabinoid inactivation enhance CaCo-2 cell endocannabinoid levels and block cell proliferation, this effect being antagonized by SR141716A. CaCo-2 cell differentiation into noninvasive cells results in increased FAAH expression, lower endocannabinoid levels, and no responsiveness to cannabinoids. CONCLUSIONS: Endocannabinoid levels are enhanced in transformed colon mucosa cells possibly to counteract proliferation via CBRs. Inhibitors of endocannabinoid inactivation may prove useful anticancer agents.