Possible role of nuclear factor erythroid 2-related factor 2 in the progression of human colon precancerous lesions

BACKGROUND

Increased levels of oxidative stress/cell inflammation contribute to colorectal cancer (CRC) onset. Nuclear factor-erythroid 2-related factor 2 (Nrf2) and its controlled growth factor erv1-like (Gfer) gene regulate redox-sensitive and anti-inflammatory mechanisms, respectively, which can contribute to promoting cancer development.

AIM

We evaluated Nrf2 and Gfer RNA expression and Nrf2 protein expression in colon mucosa in order to establish their possible involvement in the early stage of CRC.

METHODS

Forty subjects were enrolled after a histological evaluation of their colon biopsies. They included 20 subjects with a sporadic colorectal adenoma (SpCA group) and 20 without precancerous lesions (controls). Biopsy samples were processed for gene expression analysis and protein expression, using Real-time PCR and immunofluorescence confocal microscopy, respectively.

RESULTS

Nrf2 and Gfer mRNA expression were significantly reduced (p=0.007 and p<0.003, respectively) in SpCA tissues compared to normal mucosa from controls. Furthermore, immunofluorescence analysis confirmed a relevant reduction of Nrf2 in SpCA tissue compared to normal tissue from controls.

CONCLUSIONS

Our data confirm the hypothesis that Nrf2 and Gfer expression may be involved in the initial hits contributing to the multistep process of colon carcinogenesis. Further larger studies are needed to confirm if Nrf2 and Gfer are potential risk/prognostic factors for cancer development.

Helicobacter pylori Primary and Secondary Genotypic Resistance to Clarithromycin and Levofloxacin Detection in Stools: A 4-Year Scenario in Southern Italy

Antibiotic resistance has become an emerging problem for treating Helicobacter pylori (H. pylori) infection. Clarithromycin and levofloxacin are two key antibiotics used for its eradication. Therefore, we reviewed our experience with genotypic resistance analysis in stools to both clarithromycin and levofloxacin in the last four years to evaluate time trends, both in naive and failure patients. Patients collected a fecal sample using the THD fecal test device. Real-time polymerase chain reaction was performed to detect point mutations conferring resistance to clarithromycin (A2142C, A2142G, and A2143G in 23S rRNA) and levofloxacin (substitutions at amino acid position 87 and 91 of gyrA). One hundred and thirty-five naive patients were recruited between 2017-2020. Clarithromycin resistance was detected in 37 (27.4%). The time trend did not show any significant variation from 2017 to 2020 (p = 0.33). Primary levofloxacin resistance was found in 26 subjects (19.2%), and we observed a dramatic increase in rates from 2017 (10%) to 2018 (3.3%), 2019 (20%), and 2020 (37.8%). Ninety-one patients with at least one eradication failure were recruited. Secondary resistance to clarithromycin and levofloxacin was found in 59 (64.8%) and 45 patients (59.3%), respectively. In conclusion, our geographic area has a high risk of resistance to clarithromycin. There is also a progressive spreading of levofloxacin-resistant strains.

Silymarin, boswellic acid and curcumin enriched dietetic formulation reduces the growth of inherited intestinal polyps in an animal model

BACKGROUND

Some substances of plant origin have been reported to exert an effect in reducing intestinal neoplasm development, especially in animal models. Adenomatous polyposis coli multiple intestinal neoplasia - Apc^Min/+ is the most studied murine model of genetic intestinal carcinogenesis.

AIM

To assess whether an enriched nutritional formulation (silymarin, boswellic acid and curcumin) with proven “in vitro” and “in vivo” anti-carcinogenetic properties may prevent inherited intestinal cancer in animal model.

METHODS

Forty adenomatous polyposis coli multiple intestinal neoplasia - Apc^Min/+ mice were used for the study of cancer prevention. They were divided into two groups: 20 assumed standard and 20 enriched diet. At the 110^th d animals were sacrificed. In each group, four subgroups received intraperitoneal bromodeoxyuridine injection at different times (24, 48, 72 and 96 h before the sacrifice) in order to assess epithelial turnover. Moreover, we evaluated the following parameters: Intestinal polypoid lesion number and size on autoptic tissue, dysplasia and neoplasia areas by histological examination of the whole small intestine, inflammation by histology and cytokine mRNA expression by real-time polymerase chain reaction, bromodeoxyuridine and TUNEL immuno-fluorescence for epithelial turnover and apoptosis, respectively. Additionally, we performed western blotting analysis for the expression of estrogen alpha and beta receptors, cyclin D1 and cleaved caspase 3 in normal and polypoid tissues.

RESULTS

Compared to standard, enriched diet reduced the total number (203 vs 416) and the mean ± SD/animal (12.6 ± 5.0 vs 26.0 ± 8.8; P < 0.001) of polypoid lesions. In enriched diet group a reduction in polyp size was observed (P < 0.001). Histological inflammation and pro-inflammatory cytokine expression were similar in both groups. Areas of low-grade dysplasia (P < 0.001) and intestinal carcinoma (IC; P < 0.001) were significantly decreased in enriched diet group. IC was observed in 100% in standard and 85% in enriched formulation assuming animals. Enriched diet showed a faster epithelial migration and an increased apoptosis in normal mucosa and low-grade dysplasia areas (P < 0.001). At western blotting, estrogen receptor beta protein was well expressed in normal mucosa of enriched and standard groups, with a more marked trend associated to the first one. Estrogen receptor alpha was similarly expressed in normal and polypoid mucosa of standard and enriched diet group. Cleaved caspase 3 showed in normal mucosa a stronger signal in enriched than in standard diet. Cyclin D1 was more expressed in standard than enriched diet group of both normal and polypoid tissue.

CONCLUSION

Our results are suggestive of a chemo-preventive synergic effect of the components (silymarin, boswellic acid and curcumin) of an enriched formulation in inherited IC. This effect may be mediated by the reduction of epithelial proliferation, the increase of apoptosis and the acceleration of villous cell renewal due to dietary formulation intake.

Curcumin and Colorectal Cancer: From Basic to Clinical Evidences

Curcumin diffuses through cell membranes into the endoplasmic reticulum, mitochondria, and nucleus, where it exerts actions, as an antioxidant property. Therefore, its use has been advocated for chemopreventive, antimetastatic, and anti-angiogenic purposes. We conducted a literature review to summarize studies investigating the relationship between curcumin and colorectal cancer (CRC). In vitro studies, performed on human colon cancer cell lines, showed that curcumin inhibited cellular growth through cycle arrest at the G2/M and G1 phases, as well as stimulated apoptosis by interacting with multiple molecular targets. In vivo studies have been performed in inflammatory and genetic CRC animal models with a chemopreventive effect. To improve curcumin bioavailability, it has been associated with small particles that increase its absorption when orally administered with excellent results on both inflammation and carcinogenesis. Curcumin has been used, moreover, as a component of dietetic formulations for CRC chemoprevention. These combinations showed in vitro and in vivo anticarcinogenetic properties in inflammation-related and genetic CRC. A synergic effect was suggested using an individual constituent dosage, which was lower than that experimentally used "in vivo" for single components. In conclusion, curcumin falls within the category of plant origin substances able to prevent CRC in animals. This property offers promising expectations in humans.

Chemoprevention of inflammation-related colorectal cancer by silymarin-, acetyl-11-keto-beta-boswellic acid-, curcumin- and maltodextrin-enriched dietetic formulation in animal model

On the basis of preliminary in vitro experience, we assessed whether an enriched nutritional formulation with estrogen receptor (ER)-beta agonist and anti-inflammatory properties may prevent inflammation-associated colorectal cancer (CRC) in an animal model. Study sample enclosed 110 C57BL/6J male mice. Forty underwent dietary supplement safety assessment (20 standard diet and 20 enriched formulation). Seventy were treated with azoxymethane (AOM)/dextran sulfate sodium and divided into two groups: 35 received standard diet and 35 enriched formulation (curcumin, boswellic acids, silymarin and maltodextrins). Miniature colonoscopy demonstrated colitis and solid lesion development in five mice/group 100 days after first AOM injection. Mice were killed after 10 days. In each group, four subgroups received intraperitoneal bromodeoxyuridine (BrdU) injection at 24th/48th/72nd/96th hour before killing. Anti-inflammatory effect and chemoprevention were evaluated by lesion number/size, histological inflammation/dysplasia/neoplasia assessment, pro-inflammatory cytokine messenger RNA (mRNA), ER-beta/ER-alpha/BrdU immunohistochemistry and TUNEL immunofluorescence. Standard formulation assumption was associated with colon shortening compared with enriched one (P = 0.04), which reduced solid lesion number and size (P < 0.001 for both), histological inflammation score (P = 0.04), pro-inflammatory cytokine mRNA expression (P < 0.001), number of low-grade dysplasia (LGD; P = 0.03) and high-grade dysplasia (P < 0.001) areas. CRC was observed in 69.6% in standard and 23.5% in enriched formulation assuming animals (P < 0.001). Enriched formulation induced lower ER-alpha expression in CRC (P < 0.001) and higher ER-beta expression in LGD (P < 0.001) being associated to higher epithelial turnover (BrdU; P<0.001) in normal mucosa and increased apoptosis in LGD and CRC (P < 0.001 for both). Our results are promising for a successful anti-inflammatory and chemopreventive effect of enriched formulation in CRC arising from inflamed tissue.

New fecal test for non-invasive Helicobacter pylori detection: A diagnostic accuracy study

AIM

To assess the diagnostic accuracy of a new fecal test for detecting Helicobacter pylori (H. pylori), using¹³C-urea breath test as the reference standard, and explore bacterial antibiotic resistance.

METHODS

We conducted a prospective two-center diagnostic test accuracy study. We enrolled consecutive people≥ 18 years without previous diagnosis of H. pylori infection, referred for dyspepsia between February and October 2017. At enrollment, all participants underwent ¹³C-urea breath test. Participants aged over 50 years were scheduled to undergo upper endoscopy with histology. Participants collected stool samples 1-3 d after enrollment for a new fecal investigation (THD fecal test). The detection of bacterial 23S rRNA subunit gene indicated H. pylori infection. We also used the index diagnostic test to examine mutations conferring resistance to clarithromycin and levofloxacin. Independent investigators analyzed index test and reference test standard results blinded to the other test findings. We estimated sensitivity, specificity, positive (PPV) and negative (NPV) predictive value, diagnostic accuracy, positive and negative likelihood ratio (LR), together with 95% confidence intervals (CI).

RESULTS

We enrolled 294 consecutive participants (age: Median 37.0 years, IQR: 29.0-46.0 years; men: 39.8%). Ninety-five (32.3%) participants had a positive¹³C-urea breath test. Twenty-three (7.8%) participants underwent upper endoscopy with histology, with a full concordance between ¹³C-urea breath test and histology in detecting H. pylori infection. Four (1.4%) out of the 294 participants withdrew from the study after the enrollment visit and did not undergo THD fecal testing. In the 290 participants who completed the study, the THD fecal test sensitivity was 90.2% (CI: 84.2%-96.3%), specificity 98.5% (CI:96.8%-100%), PPV 96.5% (CI: 92.6%-100%), NPV 95.6% (CI: 92.8%-98.4%), accuracy 95.9% (CI: 93.6%-98.2%), positive LR 59.5(CI: 19.3-183.4), negative LR 0.10 (CI: 0.05-0.18). Out of 83 infected participants identified with the THD fecal test, 34 (41.0%) had bacterial genotypic changes consistent with antibiotic-resistant H. pylori infection. Of these, 27 (32.5%) had bacterial strains resistant to clarithromycin, 3 (3.6%) to levofloxacin, and 4 (4.8%) to both antibiotics.

CONCLUSION

The THD fecal test has high performance for the non-invasive diagnosis of H. pylori infection while additionally enabling the assessment of bacterial antibiotic resistances.

Biological markers for non-celiac gluten sensitivity: a question awaiting for a convincing answer

Non Celiac Gluten Sensitivity (NCGS) is characterized by immunological, morphological or symptomatic manifestations precipitated by gluten ingestion in individuals without celiac disease (CD). The most important challenge in NCGS is the diagnosis, currently based only on clinical observation. The "Salerno criteria" have been pointed out to achieve a reliable diagnosis even if they lack immediacy and practicality, thus making questionable patient's adherence. Therefore, biological indicators supporting the clinical diagnosis of NCGS are advisable. For these reasons, many attempts have been performed in order to identify possible serological, immunological, histopathological, immunohistochemical and pathophysiological aspects characterizing this condition with the aim of using them for diagnostic purposes. In the present narrative review, we carried out an update of the current scenario of potential markers of NCGS. The main fault of available studies is that, in most cases investigations have been pointed out towards molecules, which cannot be searched in the current laboratories of clinical analysis. Therefore, the matter has been confined within basic research. Additionally, in these studies, sensitivity and specificity of biological markers were not computable. This is a relevant limit, since an ideal test for NCGS should have a good discriminative power against both CD and other causes of microscopic enteritis. Until now, serological tests have failed, while the search for a soluble marker indicative of activation of innate immune system as well as immunohistochemistry could be the promising bases for the development of appropriate investigations in the future.

Regulation of apoptosis is impaired in atrophic gastritis associated with gastric cancer

BACKGROUND

Gastric premalignant conditions, atrophic gastritis (AG) and intestinal metaplasia (IM) are characterized by an increase of proliferation and a reduction of apoptosis in epithelial cells. The epithelial cell kinetics in AG and IM in gastric mucosa adjacent to gastric cancer is still unclear. The aim of this study was to evaluate the epithelial cell turnover and expression of proliferation and apoptosis-related genes in gastric cancer (GC) and adjacent mucosa with atrophic gastritis or intestinal metaplasia (AG/IM GC+), as well as in atrophic gastritis or intestinal metaplasia mucosa of patients without GC (AG/IM GC-) and in control biopsy samples of non-transformed gastric mucosa (Control).

METHODS

We selected 58 patients (M: F = 34:24; age range 20-84 years, median 61.06 years) with 4 well defined histological conditions: 20 controls with histological finding of non-transformed gastric mucosa, 20 patients with AG or IM (AG/IM GC-), and 18 patients with intestinal type gastric adenocarcinoma (GC) and AG or IM in the adjacent mucosa (3 cm from the macroscopic tumour margin, AG/IM GC+). We performed an immunohistochemical staining of Ki67 and TUNEL and quantitative RT-PCR to determine the expression of PCNA and Bax/Bcl-2.

RESULTS

The immunohistochemical expression of Ki67 and TUNEL in AG/IM GC- was significantly increased compared to not transformed gastric mucosa (p < 0.0001) but not compared to AG/IM in gastric mucosa adjacent to GC. Levels of Bcl-2 were reduced in GC and AG/IM GC- compared to controls as well as in AG/IM GC- compared to AG/IM in mucosa adjacent to GC+ (p < 0.05). Proliferation and apoptosis markers did not correlate with H.pylori status in our study population.

CONCLUSIONS

In AG/IM associated with GC, no significant changes in the epithelial cell turnover were detected. Decreased Bcl-2 gene expression signified atrophic gastritis and IM in presence of cancer, as well as intestinal type gastric adenocarcinoma.

Small intestinal bacterial overgrowth and celiac disease: A systematic review with pooled-data analysis

BACKGROUND

A link between small intestinal bacterial overgrowth (SIBO) and celiac disease (CD) has been hypothesized.

METHODS

Literature search was performed in main medical databases. Methods of analysis/inclusion criteria were based on Preferred Reporting Items for Systematic reviews and Meta-Analyses recommendations. The end-point was to estimate, by a pooled-data analysis, SIBO prevalence in CD. Proportions/percentages and their 95% confidence intervals (CI) were calculated by inverse variance method, whereas odd ratios (OR) and their 95% CI were estimated, where available, based on the Mantel-Haenszel method. Data were entered into the RevMan 5.3 software.

KEY RESULTS

Eleven articles fulfilled considered criteria. The pooled mean prevalence of SIBO in CD was 20% (95% CI of 10%-30%). In comparison to asymptomatic controls, CD was associated to higher risk of SIBO, with an OR of 10.52 (95% CI 2.69-41.21, P=.0007). Jejunal aspirate culture assessed SIBO prevalence of 11% (95% CI 3%-19%) in CD, whereas breath tests detected a higher value (23%, 95% CI 10%-37%). The pooled prevalence of SIBO in CD patients who were symptomatic despite a GFD was 28% (95% CI 10%-47%), higher than in asymptomatic celiac patients (pooled prevalence of 10%, with a 95% CI of 3%-16%), despite not statistically significant (P=.06). When GFD-unresponsive CD was defined only by clinical persistence of symptoms, the prevalence of SIBO was higher than in the case of villous atrophy association (31% vs 16% P=.33).

CONCLUSIONS

The heterogeneity of available studies may not support a relationship SIBO-CD. Nevertheless, SIBO could be more common in CD when symptoms do not improve after GFD.

Noninvasive molecular analysis of Helicobacter pylori: Is it time for tailored first-line therapy?

The main problem of Helicobacter pylori (H. pylori) infection management is linked to antibiotic resistances. This phenomenon has grown in the last decade, inducing a dramatic decline in conventional regimen effectiveness. The causes of resistance are point mutations in bacterial DNA, which interfere with antibiotic mechanism of action, especially clarithromycin and levofloxacin. Therefore, international guidelines have recently discouraged their use in areas with a relevant resistance percentage, suggesting first-line schedules with expected high eradication rates, i.e., bismuth containing or non-bismuth quadruple therapies. These regimens require the daily assumption of a large number of tablets. Consequently, a complete adherence is expected only in subjects who may be motivated by the presence of major disorders. However, an incomplete adherence to antibiotic therapies may lead to resistance onset, since sub-inhibitory concentrations could stimulate the selection of resistant mutants. Of note, a recent meta-analysis suggests that susceptibility tests may be more useful for the choice of first than second-line or rescue treatment. Additionally, susceptibility guided therapy has been demonstrated to be highly effective and superior to empiric treatments by both meta-analyses and recent clinical studies. Conventional susceptibility test is represented by culture and antibiogram. However, the method is not available everywhere mainly for methodology-related factors and fails to detect hetero-resistances. Polymerase chain reaction (PCR)-based, culture-free techniques on gastric biopsy samples are accurate in finding even minimal traces of genotypic resistant strains and hetero-resistant status by the identification of specific point mutations. The need for an invasive endoscopic procedure has been the most important limit to their spread. A further step has, moreover, been the detection of point mutations in bacterial DNA fecal samples. Few studies on clarithromycin susceptibility have shown an overall high sensitivity and specificity when compared with culture or PCR on gastric biopsies. On these bases, two commercial tests are now available although they have shown some controversial findings. A novel PCR method showed a full concordance between tissue and stool results in a preliminary experience. In conclusion, despite poor validation, there is increasing evidence of a potential availability of noninvasive investigations able to detect H. pylori resistances to antibiotics. These kinds of analysis are currently at a very early phase of development and caution should be paid about their clinical application. Only further studies aimed to evaluate their sensitivity and specificity will afford novel data for solid considerations. Nevertheless, noninvasive molecular tests may improve patient compliance, time/cost of infection management and therapeutic outcome. Moreover, the potential risk of a future increase of resistance to quadruple regimens as a consequence of their use on large scale and incomplete patient adherence could be avoided.

Helicobacter pylori, liver cirrhosis, and portal hypertension: an updated appraisal

OBJECTIVE

Helicobacter pylori (H. pylori) is the most common cause of gastritis and peptic ulcer. However, H. pylori is even involved in extragastric diseases, and it has been hypothesized that H. pylori could be a risk factor for several hepatic diseases. For instance, a direct involvement of H. pylori in the development of portal hypertension (PH) in cirrhotic patients has been postulated.

METHODS

We performed a literature search in major databases to elucidate the relationship between H. pylori, portal hypertension, and liver cirrhosis.

RESULTS

The effect of H. pylori on PH may be multifactorial. Endothelial dysfunction, alterations in the vasodilating dynamics, and neoangiogenesis are the most appealing theories about this issue, but the proofs come mainly from experimental studies, therefore a solid pathophysiological basis is still to be demonstrated. Congestive gastropathy (CG) and gastric antral vascular ectasia (GAVE) are two common endoscopic entities responsible for acute/chronic upper gastrointestinal bleeding, and a link with H. pylori has been hypothesized: the gastric mucosa, exposed to H. pylori, could develop both inflammatory microcirculatory alterations and thrombi, resembling the histologic pattern of GAVE.

CONCLUSIONS

Despite clues for an association between H. pylori and PH have been shown, these evidences are mostly experimental, therefore, in the absence of a direct proof on human beings, the role of H. pylori in the development of PH is uncertain. However, since this germ may be a cause of peptic ulcer, it should be found and eradicated in cirrhotic patients to reduce the risk of blood loss anemia.

Helicobacter pylori DNA isolation in the stool: an essential pre-requisite for bacterial noninvasive molecular analysis

PURPOSE

Real-time polymerase chain reaction (RT-PCR) is a widely used technique for bacterial and viral infection diagnosis. Herein, we report our preliminary experience in retrieving H. pylori genetic sequences in stools and analyzing genotypic clarithromycin resistance by RT-PCR (noninvasive), with the aim of comparing this procedure with that performed on biopsy samples (invasive).

MATERIALS AND METHODS

After 'in vitro' demonstration of H. pylori DNA detection from pure and stool-mixed bacteria, 52 consecutive patients at the first diagnosis of infection were investigated. DNA was extracted from biopsy tissue and stool samples (THD^® Fecal Test, Italy). RT-PCR was performed to detect 23S rRNA encoding bacterial subunit gene and search A2143G, A2142C, A2142G point mutations for clarithromycin resistance assessment.

RESULTS

RT-PCR showed H. pylori positive DNA in all infected patients with full concordance between tissue and stool detection (100%). We found A2143G mutation in 10 (19.2%), A2142G in 4 (7.7%) and A2142C in 5 (9.6%) patients; there was a full agreement between biopsy and fecal samples. A2143G was found in all the four A2142G positive cases and in three out of the five A2142C positive strains. Overall clarithromycin resistance rate in our series was 23%.

CONCLUSIONS

Despite the need of confirmation on large sample, stool RT-PCR analysis could represent a feasible tool to detect H. pylori DNA sequences and antibiotic resistance point mutations. As compared to tissue molecular analysis, this technique is noninvasive, with potential advantages such as improvement of patient compliance, reduction of diagnostic procedure time/cost and improvement of therapeutic outcome.

Role of concomitant therapy for Helicobacter pylori eradication: A technical note

We read with interest the recent meta-analysis by Lin et al who evaluated the effectiveness of concomitant regimen for Helicobacter pylori (H. pylori) in Chinese regions. They found that 7-d concomitant regimen is undoubtedly superior to 7-d triple therapy (91.2% vs 77.9%, P < 0.0001). However, it is a common belief that a triple therapy lasting 7 d should be definitively removed from the clinical practice for its ineffectiveness. Only its prolongation to 14 d may give satisfactory success rate. Thus, the assessment of an old and outdated treatment versus a more recent and successful one does not seem to bring novel and useful information. Moreover, a 7-d duration has not been ascertained for concomitant regimen, as main guidelines recommend a 10-d schedule for this scheme. Therefore, only studies comparing 10-d concomitant versus 14-d triple seem to be appropriate according to current Guidelines and would clarify which regimen is the most suitable worldwide. Additionally, in this meta-analysis concomitant and sequential therapy showed similar performances, despite it is common opinion that sequential is more prone than concomitant therapy to fail when metronidazole resistance occurs, and China is characterized by high rate of resistance to this antibiotic. None of the included studies evaluated a priori antibiotic resistances, and the lack of this detail hampers the unveiling of this apparent contradiction. In conclusion, the lack of the evaluation of the quality of included trials as well as their high heterogeneity constitute a burdensome limit to draw solid conclusions in this meta-analysis. On the bases of these considerations and the low number of examined trials, we believe that further studies and the knowledge of antibiotic resistances will support with high quality evidence which is the best regimen and its optimal duration.

May the assessment of baseline mucosal molecular pattern predict the development of gluten related disorders among microscopic enteritis?

AIM

To evaluate mucosal baseline mRNA expression of tissue transglutaminase 2 (tTG2), interferon gamma (IFNγ), toll-like receptor 2 (TLR2) and Myeloid Differentiation factor 88 (MyD88) in patients with microscopic enteritis (ME).

METHODS

We retrospectively enrolled 89 patients with ME of different etiology, which was defined within a 2-year mean period of follow-up. Baseline histological examination was performed on Hematoxylin-Eosin stained sections and CD3 lymphocyte immunohistochemistry was used for intraepithelial lymphocyte count (IELs). ME was defined according to the criteria of Bucharest Consensus Conference. For each patient, formalin embedded biopsy samples of the duodenum referred to the period of ME diagnosis were retrieved. Real-time polymerase chain reaction (RT-PCR) was used to detect the amount of mRNA coding for tTG2, IFNγ, TLR2 and MyD88, and the quantity was expressed as fold change compared to controls. Control group was represented by duodenal normal specimens from 15 healthy subjects undergoing endoscopy for functional symptoms. Comparisons among continuous variables were performed by One way analysis of variance (ANOVA) and Bonferroni’s test. The χ² test was used for categorical variables. Pearson’s test was used to evaluate correlations. Receiver operating curves were drawn for all four markers to estimate sensitivity and specificity in discriminating the development of CD and GS.

RESULTS

After a period of follow up of 21.7 ± 11.7 mo, the following diagnoses were achieved: gluten related disorders in 48 subjects (31 CD; 17 GS) and non-gluten related ones in 41 (29 Irritable Bowel Syndrome - IBS; 12 Others). CD patients had the highest tTG2 levels (8.3 ± 4.5). The ANOVA plus Bonferroni analysis showed that CD > Other ME > GS = IBS > negative controls. A cut off value of 2.258 was able to discriminate between CD and GS with a sensitivity of 52.94% and a specificity of 87.1%. Additionally, CD patients had the highest IFNγ levels (8.5 ± 4.1). ANOVA plus Bonferroni demonstrated CD > Other ME > GS = IBS > negative controls. A cut off of 1.853 was able to differentiate CD and GS with a sensitivity of 47.06% and a specificity of 96.77%. Patients with non gluten-related causes of ME exhibited the highest TLR2 levels (6.1 ± 1.9) as follows: Other ME > CD = GS = IBS > negative controls. TLR2 was unable to discriminate CD from GS. Patients with CD overexpressed MyD88 levels similarly to non gluten-related causes of DL (7.8 ± 4.9 and 6.7 ± 2.9), thus CD = Other ME > GS = IBS > negative controls. A cut off of 3.722 was able to differentiate CD from GS with a sensitivity of 52.94% and a specificity of 74.19%. IELs count (15-25 and more than 25/100 enterocytes) strongly correlated with mRNA levels of all tested molecules (P < 0.0001).

CONCLUSION

Our results confirm that a single marker is unable to predict a discrimination among ME underlying conditions as well as between CD and GS. Mucosal high levels of tTG and IFNγ mRNA may predict the development of CD more than GS with high specificity, despite an expected low sensitivity. TLR2 does not discriminate the development of CD from GS. MyD88 levels indicate that intestinal permeability is more increased when a severe intestinal damage underlies ME in both gluten related and unrelated conditions. Therefore, the results of the present paper do not seem to show a clear translational value.

Macronutrient intakes in obese subjects with or without small intestinal bacterial overgrowth: an alimentary survey

OBJECTIVE

Obesity is a multifactorial disorder with a possible microbiota derangement in its pathogenesis. Moreover, in obese patients the likelihood of small intestinal bacterial overgrowth (SIBO) is greater than in controls, although few studies are currently available. This study investigates the prevalence of SIBO and the possible role of dietary macronutrients in obesity.

MATERIALS AND METHODS

Sixty obese patients and normal lean controls were enrolled for SIBO detection. Diagnosis of SIBO was performed by a glucose breath test. A 24-hour recall questionnaire was administered to investigate macronutrient daily intake between the two obese patient subgroups (with/without SIBO).

RESULTS

The presence of SIBO in obese and controls was respectively 23.3% and 6.6% (p = 0.02, OR = 4.26, 95% Confidence interval = 1.31-13.84). Obese patients with SIBO ingested more carbohydrates (252.75 ± 30.53 vs 201 ± 70.76 g/day, p = 0.01), more refined sugars (104.15 ± 28.69 vs 73.32 ± 44.93 g/day, p = 0.02) and less total and insoluble fibers (9.6 ± 1.97 vs 14.65 ± 8.80 g/day, p = 0.04 and 4.7 ± 1.11 vs 8.82 ± 5.80 g/day, p = 0.01, respectively). There were no significant differences in lipid and protein intake between the two groups.

CONCLUSIONS

SIBO is widespread in obese subjects. Carbohydrates might promote the development of SIBO in obesity and fibers provide a protective function. Our results suggest a close relationship between diet and SIBO in obesity, thus supporting a possible role for intestinal microbiota.

Quinolone-based first, second and third-line therapies for Helicobacter pylori

Helicobacter pylori (H. pylori) is a very common bacterium that infects about 50% of the world population in urban areas and over 90% of people living in rural and developing countries. Fluoroquinolones, a class of antimicrobials, have been extensively used in eradication regimens for H. pylori. Levofloxacin is the most commonly used, and in second-line regimens, is one of the most effective options. However, an increasing resistance rate of H. pylori to fluoroquinolones is being observed, that will likely affect their effectiveness in the near future. Other novel fluoroquinolone molecules, such as moxifloxacin, sitafloxacin, gatifloxacin and gemifloxacin, have been proposed and showed encouraging results in vitro, although data on their clinical use are still limited. Further studies in large sample trials are needed to confirm their safety and efficacy profile in clinical practice.

Sequential vs. prolonged 14-day triple therapy for Helicobacter pylori eradication: the meta-analysis may be influenced by 'geographical weighting'

BACKGROUND

Sequential therapy is a first-line regimen obtaining satisfactory Helicobacter pylori eradication. Triple therapy prolongation improves the success rate even if a recent meta-analysis showed satisfying results only for the 14-day regimen. Studies from Africa and North America were unavailable in previous meta-analyses.

AIM

To perform a meta-analysis comparing sequential vs. prolonged 14-day triple therapy with regard to 'geographic weighting' by considering subgroups analysis according to metronidazole/clarithromycin low and high resistance areas.

METHODS

Based on PRISMA recommendations, we considered all first-line clinical studies from 2003 to November 2014. Randomised clinical trials (RCTs) were included by a search on PubMed, MEDLINE, Science Direct, EMBASE. Data on eradication rates were expressed as ITT. Risk ratio (RR), pooled RR and 95% confidence intervals were calculated by the Mantel-Haenszel method. Data were entered into RevMan 5.2 software (Nordic Cochrane Centre) using a random-effects model.

RESULTS

Databases identified 194 studies; seven met the inclusion criteria. Overall results showed a similar effectiveness of the two regimens considered (RR = 0.99; 95% CI = 0.94-1.05; p = 0.75). In areas with high resistance to clarithromycin, sequential was superior to 14-day triple therapy (RR = 0.95; 95% CI = 0.90-1.00; p = 0.03). In areas with high metronidazole resistance, sequential and 14-day triple therapy were equivalent (RR = 0.99; 95% CI = 0.91-1.08; p = 0.82).

CONCLUSIONS

'Geographic weighting' could be the main factor affecting the lack of differences between sequential and 14-day triple therapy outcomes.

Quadruple rescue therapy after first and second line failure for Helicobacter pylori treatment: comparison between two tetracycline-based regimens

BACKGROUND AND AIMS

Antibiotic resistance is the main reason for failure of Helicobacter pylori (H. pylori) treatment. Currently, guidelines recommend a treatment guided by antimicrobial susceptibility testing after two failures. However, microbial culture is not feasible everywhere, and the limited number of effective antibiotics against the bacterium narrows the options; thus a rescue therapy combining antibiotics with a low resistance may be fitting.

METHODS

Patients who have failed a first-line treatment (either prolonged triple or sequential regimens) and, successively, a levofloxacin-based triple therapy were considered for the study. Subjects underwent urea breath test (UBT), stool antigen test (ST) and endoscopy/histology to confirm the diagnosis. Cytopenia and impaired liver and kidney function were exclusion criteria. Fifty-four subjects were randomized 1:1 to two regimens: RMB Rabeprazole/Rifabutin/Minocycline/Bismuth sub-citrate or MTB Rabeprazole/Tinidazole/Minocycline/Bismuth sub-citrate both for 10 days. The results were checked 6 weeks after the end of therapy with ST/UBT plus endoscopy when indicated.

RESULTS

RMB eradicated the bacterium in 21 patients. Two subjects dropped out. The eradication rate was 77.7% (CI 62.0-93.4%) at intention-to-treat and 84.0% (CI 69.6-98.4%) at per-protocol analysis. MTB was successful in 14 patients (51.9%, CI 33.1-70.7%). No patient withdrew from the treatment for adverse events. Drug-related side effects were reported only in 3 subjects, but in all cases the treatment was carried on.

CONCLUSIONS

The association minocycline/rifabutin seems to have a synergic effect and a good therapeutic outcome in patients who have failed at least two previous regimens, although a trial on a large population is needed.

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.

Intestinal microbial metabolism of phosphatidylcholine: a novel insight in the cardiovascular risk scenario

Intestinal microbiota is a "dynamic organ" influencing host metabolism, nutrition, physiology and immune system. Among its several interactions, the role of a phosphatidylcholine metabolite derived by gut flora activity, i.e., trimethylamine-N-oxide (TMAO), allows perceiving a novel insight in the cardiovascular risk scenario, being a strong predictor of this condition. Based on current reports, including the paper of Tang et al., we describe here: the possible role of intestinal microbiota in cardiovascular risk as well as potential interventions to reduce gut flora TMAO production by diet, probiotics and antibiotics. Finally, we highlight the possibility of evaluating, monitoring and modulating TMAO in order to use its serum levels as a marker of cardiovascular risk in the next future, when the need of controlled studies on large series will be satisfied.

Non steroidal anti-inflammatory drug induced damage on lower gastro-intestinal tract: is there an involvement of microbiota?

Intestinal microbiota is composed by a community of microorganisms, which regulate intestinal functions and affect the global health. It is presumable that the well-known intestinal damages induced by Non Steroidal Antiinflammatory Drugs (NSAIDs) mirror on the homeostasis of microbiota, as confirmed by studies investigating this aspect. This review reports the evolving knowledge in this field taking into account both intestinal damage and microbiota involvement. In addition, we analyze a recent study reporting how NSAIDs change intestinal bacterial composition and, on this basis, hypothesize further possible interactions. Indeed, NSAIDs are responsible for a marked reduction of Lactobacilli, which act in the maintenance of luminal pH, mucosal permeability, enterocyte adhesion, mucus production, and immune system modulation. Moreover, Bifidobacteria are involved in the modulation of intestinal motility and local immunity and the demonstrated dangerous effect of NSAIDs could operate through an interference with these functions. A participation of microbiota in mesalazine and salycilate prevention of intestinal cancer may be supposed through their ability to stimulate bacterial production of molecules interfering with cell cycle on the basis of scanty available data. Finally, a supplementation with probiotics in chronic users of NSAIDs may help microbiota remodeling in a damaged intestine, but the poor current knowledge does not allow setting a clear indication for their use despite few evidences of a beneficial effect. In conclusion, it is presumable that the multiple effects of NSAIDs on the lower gastro-intestinal tract may involve microbiota alterations and this consideration suggests further investigations.

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 Crohn's 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.

Mucosal expression of basic fibroblastic growth factor, syndecan 1 and tumour necrosis factor-α in Crohn's disease in deep remission under treatment with anti-TNFα antibodies

BACKGROUND AND AIMS

Both inflammation and fibrosis may be detected in Crohn's disease (CD). The molecular pattern of Basic Fibroblastic Growth Factor (bFGF) and Syndecan-1 (SD1) expression is altered in stenosing CD, but we do not know what the behaviour of this teamwork factor is in CD in deep remission under treatment with anti-TNFα antibodies. Our aim was to compare the expression of bFGF, SD1 and TNF-α in patients with CD in deep remission under treatment with Infliximab (IFX) or Adalimumab (ADA) and a control group of patients with active CD.

METHODS

We assessed the expression of bFGF, SD1 and TNF-α in 10 patients with active CD and in 28 patients with CD in sustained deep remission for at least 6 months. All patients underwent surveillance colonoscopy with biopsies, while receiving maintenance therapy with IFX or ADA. Analysis was conducted by real-time reverse transcriptase PCR (RT-PCR) in biopsy samples.

RESULTS

We found that bFGF, SD1 and TNF-α were significantly reduced under treatment with anti-TNFα versus controls (p=0.000). bFGF and SD1 expression were similar between IFX and ADA patients (p=0.335 and p=0.289, respectively), while TNF-α was significantly under-expressed in ADA patients (p=0.008).

CONCLUSIONS

bFGF, SD1 and TNF-α are significantly reduced in CD patients in deep remission under treatment with anti-TNFα, likely as an expression of optimal control of inflammation. The significance of the TNF-α under-expression in patients under treatment with ADA with respect to those under treatment with IFX should be elucidated in further studies.

Mucosal molecular pattern of tissue transglutaminase and interferon gamma in suspected seronegative celiac disease at marsh 1 and 0 stages

BACKGROUND/AIM

In celiac disease (CD), there is increased mRNA coding for tissue transglutaminase (tTG) and interferon gamma (IFNα). In seronegative celiac patients, the mucosal immune complexes anti-tTG IgA/tTG are found. We assayed tTG- and IFNα-mRNA in the mucosa of patients with a clinical suspicion of seronegative CD and correlated the values with intraepithelial CD3 lymphocytes (IELs).

MATERIALS AND METHODS

Distal duodenum specimens from 67 patients were retrieved and re-evaluated for immunohistochemically proven CD3 IELs. Five 10 μm sections were used for the extraction and assay of tTG and IFNα coding mRNA levels using reverse transcriptase real-time polymerase chain reaction (RT-PCR). Samples from 15 seropositive CD patients and 15 healthy subjects were used as positive and negative controls. Results were expressed as fold-change.

RESULTS

Our series was divided into three groups based on IEL count: >25 (14 patients: group A), 15-25 (26 patients: group B), and 0-15 (27 patients: Group C). tTG-mRNA levels were (mean ± SD): CD = 9.8 ± 2.6; group A = 10.04 ± 4.7; group B = 4.99 ± 2.3; group C = 2.26 ± 0.8, controls = 1.04 ± 0.2 (CD = group A > group B > group C = controls). IFNα-mRNA levels were: CD = 13.4 ± 3.6; group A = 7.28 ± 3.6; group B = 4.45 ± 2.9; group C = 2.06 ± 1.21, controls = 1.04 ± 0.4.

CONCLUSIONS

Our results suggest that tTG- and IFNγmRNA levels are increased in both seropositive and potential seronegative patients with CD, showing a strong correlation with the CD3 IEL count at stage Marsh 1. An increase in both molecules is found even when IELs are in the range 15-25 (Marsh 0), suggesting the possibility of a "gray zone" inhabited by patients which should be closely followed up in gluten-related disorders.

Seronegative celiac disease: where is the specific setting?

The diagnosis of Celiac Disease (CD) relies on the concordance of pathological, serological, genetic and clinical features. For this reason, the diagnosis of CD is often a challenge. Seronegative celiac disease (SNCD) is defined by the negativity of anti-tissue transglutaminase antibodies in the presence of a positive histology on duodenal biopsy samples, i.e. inflammatory infiltrate of intra-epithelial lymphocytes (IELs > 25/100 enterocytes), mild villous atrophy and uneven brush border associated to human leukocyte antigen (HLA) haplotype DQ2 and/or DQ8. SNCD is characterized by mucosal deposits of tissue transglutaminase (tTG)/anti-tTG immuno-complexes. These may counteract the passage of anti-tTG into the bloodstream, thus explaining seronegativity. Another reason for seronegativity may be found in an incomplete maturation of plasma cells with a consequent failure of antibodies production. This condition often characterizes immunoglobulin deficiencies, and, indeed, SNCD is common in subjects with immunoglobulin deficiencies. The management of SNCD still remains debated. The treatment option for SNCD may be represented by gluten free diet (GFD), but the usefulness and appropriateness of prescribing GFD are controversial. Some evidences support its use only in SNCD subjects showing CD clear clinical picture and compatible HLA status. The choice of GFD administration could be linked to an investigation able to diagnose SNCD in no doubt even if a reliable test is not currently available. On these bases, a test helping the diagnosis of SNCD is justifiable and desirable.

Reversal of IgM deficiency following a gluten-free diet in seronegative celiac disease

Selective IgM deficiency (sIGMD) is very rare; it may be associated with celiac disease (CD). We present the case of an 18-year-old man with sIGMD masking seronegative CD. Symptoms included abdominal pain, diarrhea and weight loss. Laboratory tests showed reduced IgM, DQ2-HLA and negative anti-transglutaminase. Villous atrophy and diffuse immature lymphocytes were observed at histology. Tissue transglutaminase mRNA mucosal levels showed a 6-fold increase. The patient was treated with a gluten-free diet (GFD) and six months later the symptoms had disappeared, the villous architecture was restored and mucosal tissue transglutaminase mRNA was comparable to that of healthy subjects. After 1 year of GFD, a complete restoration of normal IgM values was observed and duodenal biopsy showed a reduction of immature lymphocytes and normal appearance of mature immune cells.

Expression of basic fibroblastic growth factor, syndecan 1 and tumour necrosis factor α in resected acute colonic diverticulitis

AIM

Inflammation and fibrosis are present in both colonic diverticulitis and Crohn's disease (CD). The molecular pattern of basic fibroblastic growth factor (bFGF) and syndecan 1 (SD1) expression is altered in stenosing CD, but their expression in resected complicated colonic diverticulitis (ACD) is unknown.

METHOD

The expression of bFGF, SD1 and tumour necrosis factor α (TNF-α) in 20 patients after resection of ACD was compared with 15 patients having a resection for CD. Analysis was conducted using real-time reverse transcriptase polymerase chain reaction in biopsy samples.

RESULTS

Lymphocytic and neutrophil inflammation scores were similar in both groups (P = 0.771 and P = 0.562). TNF-α and bFGF expression was significantly higher in ACD than in CD (P < 0.0001 and P = 0.009). SD1 expression was similar in both groups (P = 0.841).

CONCLUSION

TNF-α and bFGF are significantly overexpressed in ACD with respect to CD, whilst SD1 levels do not differ. The findings confirm that inflammation and its association with altered molecular patterns of mucosal healing may play an important role in the phenotype of the diseases.

Sequential, concomitant and hybrid first-line therapies for Helicobacter pylori eradication: a prospective randomized study

Helicobacter pylori eradication remains a challenge for physicians. Sequential, concomitant and the hybrid regimens have been proposed as novel, more effective therapies. We compare the efficacy of these therapies. Dyspeptic patients referred for upper endoscopy with H. pylori infection were enrolled. Patients were randomized to receive: (a) sequential therapy - 20 mg omeprazole and 1 g amoxicillin for 5 days, followed by 20 mg omeprazole, 500 mg clarithromycin and 500 mg tinidazole for the successive 5 days; (b) concomitant therapy - 20 mg omeprazole, 1 g amoxicillin, 500 mg clarithromycin and 500 mg tinidazole for either 5 days (5 day concomitant) or 14 days (14 day concomitant); or (c) hybrid therapy - 20 mg omeprazole and 1 g amoxicillin for 7 days, followed by 20 mg omeprazole, 1 g amoxicillin, 500 mg clarithromycin and 500 mg tinidazole for the successive 7 days. All drugs were given twice daily. Bacterial eradication was checked by using a [(13)C]urea breath test. In 'intention-to-treat' analysis, sequential therapy achieved the highest eradication rate, which was higher than that of 5 day concomitant therapy (90  vs 78.1 %; P = 0.02). The success rate did not statistically differ among the sequential and either 14 day concomitant (90  vs 86.3 %; P = not significant) or hybrid therapies (90  vs 82.7 %; P = not significant). The 10 day sequential, 14 day concomitant and 14 day hybrid therapies, but not the 5 day concomitant regimen, achieved similarly high eradication rates. The lower therapeutic cost coupled with the lower number of tablets needed would favour the sequential therapy as the first-line H. pylori treatment in clinical practice.

First- and second-line Helicobacter pylori eradication with modified sequential therapy and modified levofloxacin-amoxicillin-based triple therapy

BACKGROUND

Helicobacter pylori (H. pylori) treatment remains a challenge for physicians. Although highly effective, the standard sequential therapy fails in a certain number of patients. Moreover, the cure rate following a levofloxacin-amoxicillin second-line triple therapy seems to be decreasing. We tested the efficacy of modified 10-day sequential therapy, and an intensified levofloxacin-amoxicillin regimen as first- and second-line therapy respectively.

METHODS

In this prospective, open label, multicenter, pilot study H. pylori-infected patients received a first-line modified 10-day sequential therapy regimen including rabeprazole 20 mg, and amoxicillin 1 g for the first 3 days, followed by rabeprazole 20 mg, clarithromycin 250 mg, and metronidazole 250 mg, for the remaining 7 days, all drugs given thrice daily. An 8-day therapy regimen with rabeprazole 20 mg, levofloxacin 250 mg, and amoxicillin 1 g, all thrice daily, was administered a second-line therapy.

RESULTS

A total of 99 and 15 patients were enrolled for first- and second-line therapy. The eradication rates were 85.9% (95% CI 80-93) and 93.4% (95% CI 88-98) according to ITT and PP analyses following modified sequential therapy, and 60% (95% CI 35-86) and 64.3% (95% CI 39-89) following the intensified second-line therapy.

CONCLUSION

A modified sequential 3- plus 7-day regimen with thrice daily drug administration failed to achieve very high eradication rate at ITT analysis. The intensified second-line regimen achieved disappointingly low eradication rate. Novel levofloxacin-free second-line therapies are urged in Italy.

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.

How antibiotic resistances could change Helicobacter pylori treatment: A matter of geography?

Therapeutic management of Helicobacter pylori (H. pylori) remains an unsolved issue. Indeed, no therapeutic regimen is able to cure the infection in all treated patients, and in many the infection persists despite the administration of several consecutive standard therapies. Although antibiotic resistance reports describe alarming results, the outcome of therapeutic regimens does not seem to parallel this scenario in most cases, since a successful performance is often reached in more than 80% of cases. However, the phenomenon of increasing antibiotic resistance is being closely studied, and the results show controversial aspects even in the same geographic area. For the continents of Europe, America, Asia, Africa, and Oceania, minimal and maximal values of resistance to the main antibiotics (clarithromycin, amoxicillin, metronidazole, and levofloxacin) feature wide ranges in different countries. The real enigma is therefore linked to the several different therapeutic regimens, which show results that often do not parallel the in vitro findings even in the same areas. A first aspect to be emphasized is that some regimens are limited by their use in very small geographic districts. Moreover, not all therapeutic trials have considered bacterial and host factors affecting the therapeutic outcome. The additional use of probiotics may help to reduce adverse events, but their therapeutic impact is doubtful. In conclusion, the “ideal therapy”, paradoxically, appears to be a “utopia”, despite the unprecedented volume of studies in the field and the real breakthrough in medical practice made by the discovery and treatment of H. pylori. The ample discrepancies observed in the different areas do not encourage the development of therapeutic guidelines that could be valid worldwide. On these bases, one of the main challenges for the future might be identifying a successful solution to overcome antibiotic resistances. In this context, geography must be considered a relevant matter.

Fibrogenesis and fibrosis in inflammatory bowel diseases: Good and bad side of same coin?

Fibrogenesis in inflammatory bowel diseases is a complex phenomenon aimed at mucosal repair. However, it may provoke intestinal fibrosis with the development of strictures which require surgery. Therefore, fibrogenesis may be considered as a “two-faced” process when related to chronic intestinal inflammation. Many types of cells may be converted into the fibrogenic phenotype at different levels of the intestinal wall. A complex interaction of cytokines, adhesion molecules and growth factors is involved in the process. We report an overview of recent advances in molecular mechanisms of stricturizing Crohn’s disease (CD) including the potential role of trasforming growth factor beta, protein kinase C and Ras, Raf and ERK proteins. Fibrotic growth factors such as vascular endothelial growth factor and platelet-derived growth factor, as well as the Endothelial-to-Mesenchymal Transition induced by transforming growth factor-β, are considered. Finally, our experience, focused on tumor necrosis factor α (the main cytokine of inflammatory bowel diseases) and the link between syndecan 1 (a heparan sulphate adhesion molecule) and basic fibroblast growth factor (a strong stimulator of collagen synthesis) is described. We hypothesize a possible molecular pattern for mucosal healing as well as how its deregulation could be involved in fibrotic complications of CD. A final clinical point is the importance of performing an accurate evaluation of the presence of fibrotic strictures before starting anti-tumor necrosis α treatment, which could worsen the lesions.

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

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

Student's t and Fisher's 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.

Altered molecular pattern of mucosal healing in Crohn’s disease fibrotic stenosis

AIM: To investigate tumor necrosis factor-α (TNF-α), syndecan 1 and basic fibroblast growth factor (bFGF) balance in Crohn’s disease (CD) strictures.

METHODS: Our study was performed on 24 surgical specimens of CD fibrotic stenosis. Ten histological normal surgical samples were retrieved for both the large and small bowel from patients with benign conditions and healthy tissue represented control collection. Sex and age in controls did not differ from CD group. Three endoscopic biopsy specimens taken after informed consent in subjects with normal colon were also used as negative controls. TNF-α, syndecan 1 and bFGF were detected by both reverse transcriptase reverse transcriptase polymerase chain reaction after mRNA extraction (results expressed as fold-change) and immunohistochemistry.

RESULTS: TNF-α did not show any significant difference between CD and control specimens (1.54 ± 1.19; P > 0.05). Very high levels of bFGF were observed in CD (11.76 ± 4.65; P < 0.001) unlike syndecan 1 which showed a moderate increase (5.53 ± 2.18; P < 0.005). analysis of variance (ANOVA) plus Student-Neumann-Keuls showed: bFGF > syndecan 1 > TNF-α = control. Immunoreactivity for bFGF was observed in epithelial, stromal, endothelial cells and even in the muscular layer, whilst in normal tissue it was almost unexpressed. Syndecan 1 and TNF-α staining was confined to mucosal epithelial and stromal cells, while in controls syndecan 1 was found in its normal site, i.e., basolateral area of the crypts and TNF-α very poorly expressed.

CONCLUSION: Fibrotic stenosis of CD may be the final result of an irreversible transformation of different cells into fibrogenic phenotype no longer inhibited by post-transcriptional regulation.

Primary clarithromycin resistance to Helicobacter pylori: Is this the main reason for triple therapy failure?

Conventional triple therapies for Helicobacter pylori (H. pylori) eradication have recently shown a disappointing reduction in effectiveness in many countries. The main reason for failure was found to be bacterial resistance to one of the most commonly used antibiotics, clarithromycin. An additional problem for conventional triple therapy is the high rate of resistance to metronidazole found in Europe, America and Asia. In Italy, in the last 15 years a 2-fold increase in resistance has occurred. A recent study of the whole of Italy included about 20 patients from each region at the first endoscopic diagnosis of H. pylori infection. The most surprising result was the patchy distribution of resistance, which was almost absent in two regions (one northern and one southern), although the highest prevalence was found in some regions of the South. In the paediatric population we found a 25% prevalence of resistance in a sample of H. pylori positive children observed between 2002 and 2007, mirroring data obtained in southern European countries. Clarithromycin resistance assessment is currently based on phenotypic detection performed after culture the agar dilution method or E-test, and genotypic methods based on polymerase chain reaction (PCR). In a recent comparative study we found a 71.2% agreement between the two methods. Culture-free techniques are highly accurate in finding even minimal traces of genotypically resistant strains. Moreover, PCR-based tools are accurate in detecting a heteroresistant status, defined as the co-existence of some strains that are susceptible and some resistant to the same antibiotic in an individual patient. Three point mutations, namely A2143G, A2142G and A2142C, are responsible for 90% of cases of primary clarithromycin resistance in H. pylori strains isolated in Western countries, although we previously demonstrated that the presence of the A2143G mutation, but not A2142G or A2142C, significantly lowered the H. pylori eradication rate. Treatment failure has considerable cost/benefit implications because of “waste” of National Health System and patient resources, in terms of drugs, further diagnostic tests and medical examination expenses. Therefore, in future it would be very useful to be able to test for clarithromycin resistance before starting conventional triple therapy. Hopefully, fast, effective non-invasive tests may soon be devised to determine this condition.

Probiotic multistrain treatment may eradicate Helicobacter pylori from the stomach of dyspeptics: a placebo-controlled pilot study

Probiotics survive in gastric environment competing with H. pylori. We studied probiotic "multistrain" administration in dyspeptics with H. pylori (placebo-controlled study). Forty patients with H. pylori (urea breath test - UBT - and IgG) were treated for 10 days with a mixture of 8 species of probiotics. Control group represented by 40 positive subjects received placebo. A second UBT and H. pylori stool antigen (HpSA) detection were performed after 1 month. Patients who remained infected were treated with triple therapy undergoing another UBT after 30 days. A second line therapy was administered in remaining positive patients.

STATISTICS

Fisher's exact probability and Student's t tests. Thirteen out of 40 patients using probiotics became negative, while controls remained positive, irrespectively of the initial UBT delta value. No difference in the eradication rates between the two groups was found (68%-71%). After second line therapy two patients remained positive. An adequate supplementation with probiotics might eradicate H. pylori.

Mucosal expression of basic fibroblastic growth factor, Syndecan 1 and tumor necrosis factor-alpha in diverticular disease of the colon: a case-control study

BACKGROUND

Inflammation may be detected in diverticular disease (DD), and fibrosis may also develop. We assessed the mucosal expression of bFGF, SD1, and TNF-α in DD according to the severity of the disease. Moreover, we assessed the response to therapy of these cytokines in acute uncomplicated diverticulitis (AUD).

METHODS

Fifteen patients affected by AUD and seven patients affected by symptomatic uncomplicated diverticular disease (SUDD) were enrolled. Patients with asymptomatic diverticulosis (AD), segmental colitis associated with diverticulosis (SCAD), ulcerative colitis (UC), and healthy subjects (HC) served as control groups.

KEY RESULTS

The expression of bFGF, SD1, and TNF-α was significantly higher in diverticulitis than in healthy controls, in diverticulosis, and in uncomplicated diverticular disease. Cytokines were significantly higher in uncomplicated diverticular disease than in healthy controls. Cytokine expression in diverticulitis did not differ significantly from that of ulcerative colitis. After treatment, TNF-α expression dropped significantly.

CONCLUSIONS & INFERENCES

Mucosal TNF-α is overexpressed only in symptomatic DD, while SD1 and bFGF are already overexpressed in AD. Finally, TNF-α but not SD1 or bFGF expression seems to be influenced by the treatment in AUD.

Musosal tumour necrosis factor α in diverticular disease of the colon is overexpressed with disease severity

AIM

Inflammation occurs in diverticular disease (DD), but there is little information on inflammatory cytokines such as tumour necrosis factor α (TNF-α). The aim of this study was to assess TNF-α expression in DD and to see whether it is related to the severity of the disease.

METHOD

Twenty-four patients with symptomatic DD were divided into those with acute uncomplicated diverticulitis (AUD) (12 patients) and those with symptomatic uncomplicated diverticular disease (SUDD) (12 patients). Twelve further patients with asymptomatic diverticulosis (AD), six with segmental colitis associated with diverticulosis (SCAD), with ulcerative colitis (UC) and six healthy individuals (HC) were enrolled as controls. TNF-α expression in the colonic mucosa was assessed by the amount of mRNA codifying for the synthesis of TNF-α.

RESULTS

TNF-α expression was significantly higher in AUD than in HC (P=0.0007), in AD (P=0.0001) and in SUDD (P=0.0179). It was significantly higher also in SUDD than in HC (P=0.0007) and in AD (P=0.0001). TNF-α expression in AUD did not differ significantly from that in UC (P=0.0678) and SCAD (P=0.0610). It was significantly higher in UC, SCAD and AUD than in SUDD (P=0.0007, P=0.0001, P=0.0179).

CONCLUSION

TNF-α expression in DD seems to be related to the severity of the disease. In particular, it appears to be overexpressed in DD with inflammation (AUD and SUDD) compared with DD without (AD).

Helicobacter pylori clarithromycin resistance detected by Etest and TaqMan real-time polymerase chain reaction: a comparative study

The aim of the work was to compare H. pylori clarithromycin-resistance according two methods. Etest was performed on H. pylori isolated from gastric biopsy samples. TaqMan Real-Time-PCR (RT-PCR) was performed on paraffin-embedded gastric biopsy samples of the same patients. Forty-seven out of 88 strains were resistant to clarithromycin by Etest, whereas RT-PCR detected this resistance on paraffin-embedded specimens of 50 patients. RT-PCR performed on paraffin-embedded biopsy specimens of 47 patients infected with H. pylori resistant to clarithromycin as detected by Etest, revealed the presence of a resistant strain only in 40 samples. RT-PCR performed on samples of 41 patients harbouring clarithromycin-susceptible H. pylori strains showed the presence of 31 susceptible and 10 resistant strains. RT-PCR detected 18 cases with heteroresistant status. The difference between the two tests in detecting clarithromycin-resistance was not statistically significant even if RT-PCR detected more resistant cases. The genotyping resistance on paraffin-embedded gastric biopsy specimens may be used to establish resistance to clarithromycin before the treatment when culture and susceptibility testing are not available. In case of failure of an empirical clarithromycin-based triple antimicrobial treatment, RT-PCR performed on paraffin-embedded biopsy sample will establish the primary resistance to clarithromycin. In addition, this test can be useful for epidemiological investigation as well as for monitoring the evolution of clarithromycin resistance along the time.

Pathways and gene expression profiles in hepatocellular carcinoma

Hepatocarcinogenesis is a process attributed to progressive genomic changes which alter the hepatocellular phenotype producing cellular intermediates evolving into clearly neoplastic cells (hepatocellular carcinoma, HCC). During the preneoplastic phase, the liver is often the site of chronic hepatitis and/or cirrhosis, and this process leads to the production of monoclonal populations of aberrant and dysplastic hepatocytes that develop genetic and chromosomal alterations. At the moment three main molecular pathways of liver carcinogenesis have been described and several attempts of genetic classification of HCC have been proposed. The definition of genomic and molecular changes which occur during the development of HCC should improve the classification and prognostis of liver tumors. The development of sorafenib and other new targeted developing therapies were rendered possible by the discovery and understanding of the molecular and genetic pathogenesis of hepatocellular carcinoma. Besides viruses, such as Hepatitis B virus (HBV) and Hepatitis C virus (HCV), may contribute to cancer development by several ways; however, additional factors, such as host immunity and chronic inflammation and host cellular mutations also play a role in the transformation process. The understanding of these pathways will in the future enable the clinician to focus the treatment patients with HCC and customize single or combination therapy.

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.