Floriana Giorgio

Mechanisms of Helicobacter pylori antibiotic resistance: An updated appraisal

Helicobacter pylori (H. pylori) antibiotic resistance is the main factor affecting the efficacy of the current eradicating therapies. The aim of this editorial is to report on the recent information about the mechanisms accounting for the resistance to the different antibiotics currently utilized in H. pylori eradicating treatments. Different mechanisms of resistance to clarithromycin, metronidazole, quinolones, amoxicillin and tetracycline are accurately detailed (point mutations, redox intracellular potential, pump efflux systems, membrane permeability) on the basis of the most recent data available from the literature. The next hope for the future is that by improving the knowledge of resistance mechanisms, the elaboration of rational and efficacious associations for the treatment of the infection will be possible. Another auspicious progress might be the possibility of a cheap, feasible and reliable laboratory test to predict the outcome of a therapeutic scheme.

Effect of probiotic or prebiotic supplementation on antibiotic therapy in the small intestinal bacterial overgrowth: A comparative evaluation

UNLABELLED Bacterial intestinal overgrowth syndrome (SIBO) treatment is based on antibiotics. Probiotics have been shown to give similar results, whilst no study is available about prebiotics. This study evaluated the addition of probiotics or prebiotics to antibiotics on SIBO symptoms in a 6-month follow-up. We enrolled 40 patients (14 males and 26 females) reporting abdominal compliant without gastrointestinal diseases/alarm symptoms. SIBO was diagnosed by the agreement of lactulose and glucose breath tests. Patients were randomly divided into two groups homogeneous for sex and age: group 1 received Rifaximin 400 mg/day for 7 days/month followed by Lactobacillus casei for 7 days more and group 2 antibiotic followed by short chain fructo-oligosaccharides. All patients recorded a questionnaire for subjective symptom evaluation according to Rome III criteria and Bristol scale for stool characters before the study and after 6 months. STATISTICS Students t and Fishers exact tests. In group 1, a significant improvement was obtained in 5 out of 6 symptoms, whilst in group 2 in 4 out of 6 symptoms (nausea and number of bowel movements failed to improve). Despite we observed a trend of probiotics to be more effective than prebiotics, the difference in the percentage of improved symptoms was not significant (83,3% vs 66.6%; p= 0.57). Our preliminary data show a good outcome with sequential antibioticprobiotic/ prebiotic administration in patients with SIBO.

DNA sequences and proteic antigens of H. pylori in cholecystic bile and tissue of patients with gallstones

Background : Although Helicobacter pylori DNA sequences have been detected in cholecystic bile and tissue of patients with gallstones, controversial results are reported from different geographic areas.

Alrp, a survival factor that controls the apoptotic process of regenerating liver after partial hepatectomy in rats

Abstract Augmenter of Liver Regeneration (Alrp) enhances, through unknown mechanism/s, hepatocyte proliferation only when administered to partially hepatectomized (PH) rats. Liver resection, besides stimulating hepatocyte proliferation, induces reactive oxygen species (ROS), triggering apoptosis. To clarify the role of Alrp in the process of liver regeneration, hepatocyte proliferation, apoptosis, ROS-induced parameters and morphological findings of regenerating liver were studied from PH rats Alrp-treated for 72 h after the surgery. The same parameters, evaluated on regenerating liver from albumin-treated PH rats, were used as control. The results demonstrated that Alrp administration induces the anti-apoptotic gene expression, inhibits hepatocyte apoptosis and reduces ROS-induced cell damage. These and similar data from in vitro studies and the presence of ‘Alrp homologous proteins’ in viruses as well as in mammals (i) allow to hypothesize that Alrp activity/ies may not be exclusive for regenerating liver and (ii) suggest the use of Alrp in the treatment of oxidative stress-related diseases.

Change of point mutations in Helicobacter pylori rRNA associated with clarithromycin resistance in Italy.

Primary clarithromycin resistance is the main factor affecting the efficacy of Helicobacter pylori therapy. This study aimed: (i) to assess the concordance between phenotypic (culture) and genotypic (real-time PCR) tests in resistant strains; (ii) to search, in the case of disagreement between the methods, for point mutations other than those reported as the most frequent in Europe; and (iii) to compare the MICs associated with the single point mutations. In order to perform real-time PCR, we retrieved biopsies from patients in whom H. pylori infection was successful diagnosed by bacterial culture and clarithromycin resistance was assessed using the Etest. Only patients who had never been previously treated, and with H. pylori strains that were either resistant exclusively to clarithromycin or without any resistance, were included. Biopsies from 82 infected patients were analysed, including 42 strains that were clarithromycin resistant and 40 that were clarithromycin susceptible on culture. On genotypic analysis, at least one of the three most frequently reported point mutations (A2142C, A2142G and A2143G) was detected in only 23 cases (54.8%), with a concordance between the two methods of 0.67. Novel point mutations (A2115G, G2141A and A2144T) were detected in a further 14 out of 19 discordant cases, increasing the resistance detection rate of PCR to 88% (P<0.001; odds ratio 6.1, 95% confidence interval 2-18.6) and the concordance to 0.81. No significant differences in MIC values among different point mutations were observed. This study suggests that: (i) the prevalence of the usually reported point mutations may be decreasing, with a concomitant emergence of new mutations; (ii) PCR-based methods should search for at least six point mutations to achieve good accuracy in detecting clarithromycin resistance; and (iii) none of the tested point mutations is associated with significantly higher MIC values than the others.

Mucosal assessment of tumor necrosis factor alpha levels on paraffined samples: a comparison between immunohistochemistry and real time polymerase chain reaction

Author(s) : Enzo IerardiArticle title : Mucosal assessment of tumor necrosis factor alpha levels on paraffined samples:a comparison between immunohistochemistry and real time polymerase chainreactionArticle no : 483739Dear Author,Please check these proofs carefully. It is the responsibility of the corresponding author to checkagainst the original manuscript and approve or amend these proofs. A second proof is notnormally provided. Informa Healthcare cannot be held responsible for uncorrected errors, even ifintroduced during the composition process. The journal reserves the right to charge for excessiveauthor alterations, or for changes requested after the proofing stage has concluded.The following queries have arisen during the editing of your manuscript and are marked in themargins of the proofs. Unless advised otherwise, submit all corrections using the CATS onlinecorrection form. Once you have added all your corrections, please ensure you press the “SubmitAll Corrections” button.

Evolution of nonspecific duodenal lymphocytosis over 2 years of follow-up.

AIM To assess the evolution of duodenal lymphocytosis (DL), a condition characterized by increased intraepithelial lymphocytes (IELs), over 2 years of follow-up. METHODS Consecutive patients undergoing upper endoscopy/histology for abdominal pain, diarrhea, weight loss, weakness or other extraintestinal features compatible with celiac disease (CD) were included. Evaluation of IELs infiltrate in duodenal biopsy samples was carried out by CD3-immunohistochemistry and expressed as number of positive cells/100 enterocytes. Diagnostic agreement on the IELs count was tested by calculating the weighted k coefficient. All patients underwent serological detection of autoantibodies associated with CD: IgG and IgA anti-tissue transglutaminase and endomysium. Each patient underwent further investigations to clarify the origin of DL at baseline and/or in the course of 2 years of follow-up every six months. Autoimmune thyroiditis, intestinal infections, parasitic diseases, bacterial intestinal overgrowth, hypolactasia and wheat allergy were detected. Colonoscopy and enteric magnetic resonance imaging were performed when necessary. Risk factors affecting the final diagnosis were detected by multinomial logistic regression and expressed as OR. RESULTS Eighty-five patients (16 males, 69 females, aged 34.1 ± 12.5 years) were followed up for a mean period of 21.7 ± 11.7 mo. At baseline, endoscopy/duodenal biopsy, CD3 immunohistochemistry revealed: > 25 IELs/100 enterocytes in 22 subjects, 15-25 IELs in 37 and < 15 IELs in 26. They all had negative serum anti-transglutaminase and anti-endomysium, whilst 5 showed IgG anti-gliadin positivity. In the course of follow-up, 23 developed CD seropositivity and gluten sensitivity (GS) was identified in 19. Other diagnoses were: 5 Helicobacter pylori infections, 4 jejunal Crohns disease, 1 lymphocytic colitis and 1 systemic sclerosis. The disease in the remaining 32 patients was classified as irritable bowel syndrome because of the lack of diagnostic evidence. At multivariate analysis, the evolution towards CD was associated with an IELs infiltrate > 25 (OR = 1640.4) or 15-25 (OR = 16.95), human leukocyte antigen (HLA) DQ2/8 (OR = 140.85) or DQA1*0501 (OR = 15.36), diarrhea (OR = 5.56) and weakness (OR = 11.57). GS was associated with IELs 15-25 (OR = 28.59), autoimmune thyroiditis (OR = 87.63), folate deficiency (OR = 48.53) and diarrhea (OR = 54.87). CONCLUSION DL may have a multifactorial origin but the IELs infiltrate and HLA are strong predictive factors for CD development and a clinical diagnosis of GS.

Metabolic syndrome and gastro-esophageal reflux: A link towards a growing interest in developed countries

The aim of this Editorial is to describe the growing possibility of a link between gastro-esophageal reflux disease (GERD) and metabolic syndrome on the light of recent epidemiological and pathophysiological evidence. The state of the art of GERD is described, based on recent definitions, pathophysiological evidence, epidemiology in developed countries, clinical subtypes together with a diagnostic approach specifically focussed on the appropriateness of endoscopy. Metabolic syndrome is accurately defined and the pivotal role of insulin resistance is emphasized. The strong relationship between GERD and metabolic syndrome has been pathophysiologically analyzed, taking into account the role of obesity, mechanical factors and metabolic changes. Data collected by our group regarding eating habits and GERD are briefly summarized at the end of a pathophysiological analysis. The literature on the subject strongly supports the possibility that lifestyle and eating habits may be involved in both GERD and metabolic syndrome in developed countries.

Infliximab therapy downregulation of basic fibroblast growth factor/syndecan 1 link: a possible molecular pathway of mucosal healing in ulcerative colitis

Background It is known that syndecan 1 in inflammatory bowel diseases is able to migrate from epithelial basolateral site to the stromal area and apical surface of epithelium with a consequent activation and modulation of basic fibroblast growth factor (bFGF), and this process sustains mucosal healing of ulcers. On the other hand, tumour necrosis factor (TNF) α mucosal levels are directly related to the entity of the damage in these disorders. Aim of the study A ‘post-hoc’ retrospective study was performed to estimate mucosal TNF α in rectal biopsies of subjects with ulcerative colitis (UC) before and after effective infliximab therapy and its relationship with syndecan 1, bFGF and endoscopic mucosal healing. Material and methods Paraffin-embedded rectal samples from 12 patients with UC responders to infliximab were analysed for TNF α, syndecan 1 and bFGF before and 6 months after therapy using a real-time reverse transcriptase polymersase chain reaction. Additionally, syndecan 1 location was evaluated by immunohistochemistry. Samples from 12 subjects with irritable bowel symptoms without endoscopic/histological abnormalities represented the control group. Mucosal healing induced by the treatment was defined by an endoscopic Mayo subscore changing from 2–3 to 0. ANOVA plus Student–Newman–Keuls was used for statistical analysis. Results The authors found that in the active disease, an increase in TNF α (p<0.001) is accompanied by raised levels of both syndecan 1 (p<0.005) and bFGF (p<0.005) compared with the control group. Infliximab-induced TNF α decrease to levels similar to controls is associated with both endoscopic mucosal healing and adhesion molecule/growth factor significant reduction. Additionally, syndecan 1 location, which is predominant in the stromal cells and apical epithelium in the active disorder, is quite exclusively located at the basolateral epithelial area in both healed mucosa and controls. Conclusions Balanced interaction among TNF α inhibition by infliximab, syndecan 1 migration, bFGF repair modulation and final adhesion molecule reversal to its normal location might represent a suitable molecular pathway of endoscopic mucosal healing in UC.

Seronegative Celiac Disease and Immunoglobulin Deficiency: Where to Look in the Submerged Iceberg?

In the present narrative review, we analyzed the relationship between seronegative celiac disease (SNCD) and immunoglobulin deficiencies. For this purpose, we conducted a literature search on the main medical databases. SNCD poses a diagnostic dilemma. Villous blunting, intraepithelial lymphocytes (IELs) count and gluten “challenge” are the most reliable markers. Immunohistochemistry/immunofluorescence tissue transglutaminase (tTG)-targeted mucosal immunoglobulin A (IgA) immune complexes in the intestinal mucosa of SNCD patients may be useful. In our experience, tTG-mRNA was similarly increased in seropositive celiac disease (CD) and suspected SNCD, and strongly correlated with the IELs count. This increase is found even in the IELs’ range of 15–25/100 enterocytes, suggesting that there may be a “grey zone” of gluten-related disorders. An immune deregulation (severely lacking B-cell differentiation) underlies the association of SNCD with immunoglobulin deficiencies. Therefore, CD may be linked to autoimmune disorders and immune deficits (common variable immunodeficiency (CVID)/IgA selective deficiency). CVID is a heterogeneous group of antibodies dysfunction, whose association with CD is demonstrated only by the response to a gluten-free diet (GFD). We hypothesized a familial inheritance between CD and CVID. Selective IgA deficiency, commonly associated with CD, accounts for IgA-tTG seronegativity. Selective IgM deficiency (sIgMD) is rare (<300 cases) and associated to CD in 5% of cases. We diagnosed SNCD in a patient affected by sIgMD using the tTG-mRNA assay. One-year GFD induced IgM restoration. This evidence, supporting a link between SNCD and immunoglobulin deficiencies, suggests that we should take a closer look at this association.