Abnormal gut motility in inflammatory bowel disease: an update

BACKGROUND

There is substantial evidence linking disturbed gastrointestinal motility to inflammation. Thus, it is not surprising that abnormalities of gastrointestinal motility play a role in inflammatory bowel disease (IBD), affecting patient outcomes. We performed a review of the literature to investigate the relationship between abnormal gut motility and IBD.

METHODS

With an extensive literature search, we retrieved the pertinent articles linking disturbed gut motility to IBD in various anatomical districts.

RESULTS

The evidence in the literature suggests that abnormal gastrointestinal motility plays a role in the clinical setting of IBD and may confuse the clinical picture.

CONCLUSIONS

Abnormal gut motility may be important in the clinical setting of IBD. However, additional data obtained with modern techniques (e.g., magnetic resonance imaging) are needed to individuate in a more precise manner gastrointestinal motor dysfunctions, to understand the nature of clinical manifestations and properly tailor the treatment of patients.

Treatment of Helicobacter pylori infection in 2018

Treatment options for the eradication of Helicobacter pylori continue to evolve. There have been many guidelines for H. pylori treatment published, which may lead to some confusion. However, most are in agreement with the most recent iteration of the Maastricht treatment guidelines. Triple therapy is still the most frequently used treatment, especially in areas of low clarithromycin resistance. Its best results are achieved when taken for a minimum of 10 days and with high-dose acid suppression. Quadruple therapy is gaining in popularity particularly in areas with increasing resistance to standard triple therapy. Whether three antibiotics, or bismuth and two antibiotics are used, excellent eradication rates are achieved, albeit with increased side effects. Levofloxacin second-line therapy is widely used; however bismuth, when available, is an increasingly successful option. Sequential therapy is challenging in terms of compliance and is no longer recommended. This past year witnessed a notable increase in the number of studies based on antimicrobial susceptibility testing and tailored eradication therapy, reflecting the role of culture-guided treatment, which may well represent the future of H. pylori treatment and prevent the inappropriate use of antibiotics.

Helicobacter pylori infection and occurrence of celiac disease in subjects HLA-DQ2/DQ8 positive: A prospective study

BACKGROUND

Celiac disease (CD) occurs in subjects positive for HLA-DQ2 and/or DQ8 gene loci at any age following ingestion of gluten-containing food. An increased permeability of the mucosa allows interactions between gliadin macromolecules and genetic factors. It has been observed that Helicobacter pylori has the ability to modulate the integrity of the duodenal epithelium. We aimed to determine whether H. pylori infection may enhance the occurrence of CD in genetically susceptible subjects.

MATERIALS AND METHODS

This was a prospective observational study. Patients undergoing upper endoscopy for any reason and positive for HLA-DQ2 and/or DQ8 haplotypes with or without CD were included. H. pylori infection was defined as a positive gastric histopathology and/or 13C-urea breath test. Prevalence of infection was compared between enrolled subjects with and without CD. Multiple logistic regression analysis, adjusting odds ratios for patient age, gender, smoking habit, residency, body mass index, and assumption of nonsteroidal anti-inflammatory drugs (NSAIDs) and proton-pump inhibitors (PPIs) were performed.

RESULTS

A total of 397 genetically susceptible individuals (mean age: 37.7 ± 15.3 years; 86% women) were enrolled between October 2014 and October 2017. There were 265 (68%) patients with a diagnosis of CD. Overall, the prevalence of H. pylori infection was 33% and was similar in patients with and without CD (32% vs 36%). Adjustment for all covariates did not reveal any significant association, although adjusted odds ratio (OR) for CD was higher in female (OR = 1.302), in patients H. pylori positive (OR = 1.277), followed by use of NSAIDs (OR = 1.126), respectively. The use of PPIs appeared to be mildly protective against CD (OR = 0.644).

CONCLUSION

Our study did not reveal any significant relationship between H. pylori and CD risk, even taking into account other confounders. More importantly, our findings do not support a "protective" role of H. pylori infection against CD, as previously reported. Therefore, there are no reasons to avoid eradication of H. pylori also in subject genetically susceptible for CD.

Role of Helicobacter pylori Infection in Body Height of Adult Dyspeptic Patients

INTRODUCTION

The prevalence of H. pylori infection is high in underdeveloped countries and is associated with growth retardation. In the first half of the 20th century, Sardinia was an underdeveloped region; however, more recent development resulted in a decline in H. pylori infection. Because body height is correlated with health and nutritional status in childhood, the association among H. pylori infection and height was explored.

MATERIALS AND METHODS

A retrospective observational study was conducted involving patients undergoing endoscopy for dyspepsia from 2002 to 2012. H. pylori status was assessed by histology plus the rapid urease test or 13Carbon-urea breath test.

RESULTS

Body height and H. pylori status were assessed in 5045 adult patients: 3257 (64.6%) were women. Patients born after 1950 showed a significant increase in height (average 3.22 cm) compared to patients born before 1950 (163.93 vs 160 cm; 95% confidence interval, CI = 2.74-3.70 cm) (p < .0001). H. pylori-infected patients were nearly 1 cm shorter than uninfected patients (95% CI = -1.35 to·-0.09 cm) (p = .012). The multivariate linear regression analysis showed male gender, birth cohort, and occupational categories to be strongly associated with height, while the weak effect of H. pylori infection disappeared.

CONCLUSIONS

Our results demonstrate a strong secular trend related to body height in Sardinia with a minimal influence of H. pylori infection.

Glucose-6-phosphate dehydrogenase deficiency and risk of colorectal cancer in Northern Sardinia: A retrospective observational study

Glucose-6-phosphate dehydrogenase (G6PD) deficiency has been associated with a lower cancer risk, possibly via a reduction of mutagenic oxygen-free radicals and by reducing nicotinamide-adeninedinucleotide-phosphate for replicating cells. In Sardinia, the enzyme defect is frequent as a consequence of selection by malaria in the past. This study investigated the relationship between G6PD deficiency and colorectal cancer (CRC).A retrospective case-control study of 3901 patients from Sardinia, who underwent a colonoscopy between 2006 and 2016, was performed. G6PD phenotype was assessed for each subject. The proportion of pre and malignant colorectal lesions was compared in cases (G6PD-deficient) and controls (G6PD-normal). Data concerning age, sex, family history of CRC, smoking habits, body height, and weight, and also associated diseases were collected.The CRC risk reduction was 43.2% among G6PD-deficient compared with G6PD-normal subjects (odds ratio 0.57, 95% confidence interval 0.37-0.87, P = 0.010). Age, sex, family history of CRC, and also comorbidities such as type 1 diabetes and ischemic heart disease, were significantly associated with CRC risk. The protective effect of G6PD deficiency remained significant after adjusting for all covariates by logistic regression analysis, and was consistently lower across all age groups.Glucose-6-phosphate dehydrogenase enzyme deficiency is associated with a reduced risk of CRC.

Helicobacter pylori CagA antibodies and thyroid function in latent autoimmune diabetes in adults

OBJECTIVE

H. pylori infection is reportedly associated with autoimmune diseases such as chronic thyroiditis and autoimmune diabetes. The aim of this study is to determine the association between H. pylori infection and its virulent strain CagA with antibodies against thyroperoxidase (TPO Ab) and thyrotropin (TSH) in a cohort of latent autoimmune diabetes in adult (LADA) patients.

PATIENTS AND METHODS

We included 234 LADA patients (53.8% women). Antibodies against H. pylori whole antigens and CagA, TPO Ab and TSH were assessed in all patients.

RESULTS

Prevalence of IgG against H. pylori and GagA was 52.1% and 20.9% respectively. Antibodies against H. pylori were not associated with TPO Ab and TSH (rho = 0.067, p = 0.620 and rho = 0.156, p = 0.099, respectively). Antibodies against CagA showed a positive association with TSH and TPO Ab (respectively rho = 0.309, p = 0.036 and rho = 0.419, p = 0.037). Subjects with hypothyroidism (TSH ≥ 3.5 μU/ml) had an increased frequency of Ab anti CagA (p = 0.059).

CONCLUSIONS

The infection by H. pylori strains expressing CagA is associated with increased TPO Ab and TSH levels in LADA patients, suggesting a possible mechanism involved in thyroid autoimmunity and dysfunction of the gland. Further research is needed to test this hypothesis.

Inclusion of Lactobacillus Reuteri in the Treatment of Helicobacter pylori in Sardinian Patients: A Case Report Series

Clinical studies have shown that bismuth-containing quadruple therapy given twice a day for 10 to 14 days is effective and safe in the treatment of Helicobacter pylori infection in Sardinia. However, bismuth is no longer available in Italy. To report the effectiveness and tolerability of pantoprazole 20 mg, tetracycline 500 mg, and metronidazole 500 mg given b.i.d. (with the midday and evening meals) for 10 days supplemented with Lactobacillus reuteri (DSM 17938) 10(8)  cfu/tablet once a day for 20 days in patients treated in a routine daily practice setting. H pylori infection was defined as a positive gastric histopathology and/or 13C-Urea Breath Test (UBT) and/or stool antigen testing. Successful eradication was documented by 13C-UBT, and/or stool antigen assay at least 4 weeks post-therapy. Compliance and side effects were recorded after completing treatment. A total of 45 patients (10 men, 35 women; mean age 52.6 years) have completed the treatment regimen with the success rate of 93% (95% confidence interval = 85-99%). Compliance was excellent. Side effects were absent or generally mild.Proton pump inhibitor-tetracycline-metronidazole-L reuteri therapy provided high eradication rates with few side effects and therefore can safely replace bismuth in H pylori treatment. Further studies are needed that include susceptibility testing.

Implication of Cytotoxic Helicobacter pylori Infection in Autoimmune Diabetes

Background. Type 1 diabetes (T1D) and type 2 diabetes (T2D) have been linked to Helicobacter pylori infection, although results are conflicting. No previous study addressed a possible link between H. pylori infection and latent autoimmune diabetes in adults (LADA). In this study, a correlation among H. pylori infection and the risk of autoimmune diabetes in comparison with T2D was investigated. Methods. Sera from 234 LADA patients, 105 patients with late-onset T1D, and 156 patients with T2D were analyzed for anti-H. pylori and the cytotoxin-associated antigen (CagA) IgG antibodies. Results. H. pylori seroprevalence was comparable in LADA (52%), late-onset T1D (45%), and T2D (49%) with no gender differences. The seroprevalence of CagA IgG was significantly higher in autoimmune diabetes (late-onset T1D: 45%, LADA: 40%) compared to T2D (25%; p < 0.028). Conclusions. Although H. pylori seroprevalence was similar in LADA, T1D, and T2D, anti-CagA positivity was significantly increased among patients with autoimmune diabetes, suggesting that more virulent H. pylori strains might be a trigger for immune mechanisms involved in their pathogenesis.

Anti-Thyroid Peroxidase Antibodies and Male Gender Are Associated with Diabetes Occurrence in Patients with Beta-Thalassemia Major

BACKGROUND

Intensive transfusion schedule and iron-chelating therapy prolonged and improved quality of life in patients with β-thalassemia (β-T) major. However, this led to an increased risk of developing impaired glucose tolerance or diabetes. In this study we analyzed variables associated with the occurrence of impaired glucose tolerance or diabetes in patients with β-T major.

METHODS

388 Sardinian patients were included. Age, gender, duration of chelation therapy, body mass index, and markers of pancreatic and extrapancreatic autoimmunity were analyzed.

RESULTS

Multiple logistic regression analysis showed that anti-thyroid peroxidase (TPO) antibodies (Ab) (OR = 3.36; p = 0.008) and male gender (OR = 1.98; p = 0.025) were significantly associated with glucose impairment, while the other variables were not. Ferritin levels were significantly higher in TPOAb positive compared to TPOAb negative patients (4870 ± 1665 μg/L versus 2922 ± 2773 μg/L; p < 0.0001).

CONCLUSIONS

In patients with β-T major a progressive damage of insulin-producing cells due to secondary hemosiderosis appears to be the most reasonable mechanism associated with glucose metabolism disorders. The findings need to be confirmed with additional well designed studies to address the question of whether TPOAb may have a role in the management of these patients.

Myenteric plexitis: A frequent feature in patients undergoing surgery for colonic diverticular disease

BACKGROUND

Diverticular disease of the colon is frequent in clinical practice, and a large number of patients each year undergo surgical procedures worldwide for their symptoms. Thus, there is a need for better knowledge of the basic pathophysiologic mechanisms of this disease entity.

OBJECTIVES

Because patients with colonic diverticular disease have been shown to display abnormalities of the enteric nervous system, we assessed the frequency of myenteric plexitis (i.e. the infiltration of myenteric ganglions by inflammatory cells) in patients undergoing surgery for this condition.

METHODS

We analyzed archival resection samples from the proximal resection margins of 165 patients undergoing left hemicolectomy (60 emergency and 105 elective surgeries) for colonic diverticulitis, by histology and immunochemistry.

RESULTS

Overall, plexitis was present in almost 40% of patients. It was subdivided into an eosinophilic (48%) and a lymphocytic (52%) subtype. Plexitis was more frequent in younger patients; and it was more frequent in those undergoing emergency surgery (50%), compared to elective (28%) surgery (p = 0.007). All the severe cases of plexitis displayed the lymphocytic subtype.

CONCLUSIONS

In conclusion, myenteric plexitis is frequent in patients with colonic diverticular disease needing surgery, and it might be implicated in the pathogenesis of the disease.

Risk factors associated with colonic diverticulosis among patients from a defined geographic area

BACKGROUND

Only a few data regarding colonic diverticulosis are available in Italy. We examined the frequency of colonic diverticulosis and its associations with risk factors in a homogeneous Northern Sardinian population undergoing colonoscopy for any reason in the last decades.

METHODS

This was a retrospective single-center study. Medical records of patients undergoing colonoscopy for any indication between 1995 and 2013 were reviewed. Demographic information including age, gender, geographic area (urban, rural), marital status, smoking habit, occupation, body mass index, and comorbidities were collected. Presence, number, and extension of diverticula were assessed by colonoscopy. The diagnosis of diverticulosis was defined by the presence of more than five diverticula.

RESULTS

A total of 4458 records were collected (39.8 % males). Analysis by birth cohorts showed a significant progressive age-related increase in the prevalence of diverticulosis. The average prevalence was 18.9 % without significant variation across the 19-year observation period. In 101 (12.1 %) subjects diverticula were single or few. Seventy-one percent of diverticula were located predominantly in the left side, 2 % in the right side, and 14.3 % were spread throughout the colon. There was a significant association with obesity but not with smoking habits, marital status, or urban versus rural environment. A strong association was observed between the presence of diverticulosis and cardiovascular and other gastrointestinal and lung disease (p < 0.0001). These associations were also confirmed by the logistic regression analysis.

CONCLUSIONS

In this endoscopic study, colonic diverticulosis in Northern Sardinia showed prevalence similar to other series in Western countries, and it was predominantly left sided and age related.

Is There a Role for Probiotics in Helicobacter pylori Therapy?

The role of probiotics in Helicobacter pylori therapy remains unclear. Lactobacilli can be shown to inhibit H pylori in vitro. Some strains of Lactobacilli may exert specific antimicrobial effects. There is no strong evidence of a benefit on eradication rate when probiotics are added to a regimen. Despite promising results obtained using compounds of L reuteri and S boulardii, high-quality trials are needed to define the role of probiotics as adjuvant therapy. Variables that remain to be studied with L reuteri, currently the most promising strain, include dosage, frequency of administration, administration in relation to meals, and duration of therapy.

Tissue resonance interaction accurately detects colon lesions: A double-blind pilot study

AIM: To investigated the performance of the tissue resonance interaction method (TRIM) for the non-invasive detection of colon lesions.

METHODS: We performed a prospective single-center blinded pilot study of consecutive adults undergoing colonoscopy at the University Hospital in Sassari, Italy. Before patients underwent colonoscopy, they were examined by the TRIMprobe which detects differences in electromagnetic properties between pathological and normal tissues. All patients had completed the polyethylene glycol-containing bowel prep for the colonoscopy procedure before being screened. During the procedure the subjects remained fully dressed. A hand-held probe was moved over the abdomen and variations in electromagnetic signals were recorded for 3 spectral lines (462-465 MHz, 930 MHz, and 1395 MHz). A single investigator, blind to any clinical information, performed the test using the TRIMprob system. Abnormal signals were identified and recorded as malignant or benign (adenoma or hyperplastic polyps). Findings were compared with those from colonoscopy with histologic confirmation. Statistical analysis was performed by χ² test.

RESULTS: A total of 305 consecutive patients fulfilling the inclusion criteria were enrolled over a period of 12 months. The most frequent indication for colonoscopy was abdominal pain (33%). The TRIMprob was well accepted by all patients; none spontaneously complained about the procedure, and no adverse effects were observed. TRIM proved inaccurate for polyp detection in patients with inflammatory bowel disease (IBD) and they were excluded leaving 281 subjects (mean age 59 ± 13 years; 107 males). The TRIM detected and accurately characterized all 12 adenocarcinomas and 135/137 polyps (98.5%) including 64 adenomatous (100%) found. The method identified cancers and polyps with 98.7% sensitivity, 96.2% specificity, and 97.5% diagnostic accuracy, compared to colonoscopy and histology analyses. The positive predictive value was 96.7% and the negative predictive value 98.4%. Among the 281 non-IBD subjects, there were 7 cases with discordant results (2.5%) between TRIMprob and the reference standard including 5 false positive results (1.8%) and 2 false negative (0.7%) results. The main limitation of the TRIMprob system is the need for trained operators.

CONCLUSION: The study confirmed that TRIM provides rapid, accurate, convenient and noninvasive means to identify individuals most likely to benefit from colonoscopy.

The PNEI holistic approach in coloproctology

The psycho-neuroendocrine-immune approach relies on the concept of considering diseases from a holistic point of view: the various components (psyche, nervous system, endocrine system, and immune system) control the diseased organ/apparatus and in turn are influenced by a feedback mechanism. In this article, we will consider the psycho-neuroendocrine-immune approach to coloproctological disorders, by providing clinical cases and discussing them in light of this approach.

Is aphallic vas deferens development in females related to the distance from organotin sources? A study with Stramonita haemastoma

Imposex, a syndrome characterized by the appearance of a penis and/or vas deferens in female gastropods due the presence of organotins in environment, is still observed in Brazilian gastropod populations, as in other countries, even after the tributyltin (TBT) ban. Nevertheless, the progressive controls on the use of organotins in antifouling systems at national and international levels and the consequent reduction of their environmental concentrations have led to changes in the characteristics of imposex development observed in Stramonita haemastoma. Populations of this species were analyzed on the coast of Rio de Janeiro (Brazil) between 2007 and 2008, and the developmental pathways associated with the syndrome were identified. Compared with previous works, it was noted that imposex expression was reduced in most of Guanabara Bay. Aphallic imposex development, on the other hand, showed a marked increase. The pathways of imposex development were also evaluated in a temporal data series from a fixed sampling station at Vermelha beach, and the incidence of aphallic imposex development was found to show a marked increase from 1998 onward. Furthermore, the observation of either the presence or absence of a penis in imposex-affected females may indicate that penis development is related to the contaminant exposure level and that the decreasing TBT concentrations in the local environment result in the predominance of an aphallic route of imposex development. These findings support the idea that imposex female aphally in this species could be a dose-dependent response, rather than a genetic anomaly.

Gastrointestinal symptoms and Helicobacter pylori infection in school-age children residing in Porto Torres, Sardinia, Italy

BACKGROUND

Helicobacter pylori infection is typically acquired in childhood, and following the acute event, it is thought that most infections remain asymptomatic. H. pylori has been suggested to protect against diarrhea in childhood.

AIM

To examine the role of H. pylori in gastrointestinal symptoms in children.

MATERIALS AND METHODS

A cross-sectional sero-epidemiologic study was conducted in Porto Torres, Sardinia, Italy. Demographic information, socioeconomic factors, and the frequency of upper gastrointestinal symptoms during the previous 3 months (e.g., abdominal pain, diarrhea, nausea, heartburn, halitosis, slow digestion, belching, and weight loss) were evaluated by a questionnaire. H. pylori status was determined by ELISA.

RESULTS

Approximately 95% (N = 1741) of school children between the age of 6 and 15 years from Porto Torres participated. The sero-prevalence of H. pylori infection was 13.3% (229/1727) and similar in boys (13%) and girls (14%) (p = .57). Nausea/vomiting (odds ratio (OR) = 2.2 (95% CI = 1.2-5.1)) and diarrhea (OR = 2.1 (95% CI = 1.3-2.8)) were each significantly associated with H. pylori infection, and these associations remained significant after controlling for other study variables. There was no significant association between H. pylori and abdominal pain or heartburn (p > .25).

CONCLUSIONS

The study does not support either a role of H. pylori infection in abdominal pain in children or a protective role against diarrheal illnesses or nausea/vomiting.

Role of routine small intestinal biopsy in adult patient with irritable bowel syndrome-like symptoms

AIM

The clinical evaluation of patients with chronic diarrhea and/or abdominal pain requires a complex work-up. The aim of the study was to evaluate whether routine duodenal biopsy sampling of macroscopically normal mucosa of patients with irritable bowel syndrome-like symptoms undergoing upper endoscopy assists in diagnosis and management.

METHODS

Consecutive adults scheduled for upper endoscopy for evaluation of uninvestigated dyspepsia and abdominal pain and/or chronic diarrhea based upon the history, were enrolled. Gastric biopsies and 3 duodenal biopsies were taken for histological evaluation.

RESULTS

A total of 786 sets of biopsies from 262 consecutive patients (200 females and 62 males, mean age 46 years; range: 15-82), were analyzed. Microscopic damage was observed in 212 of 262 patients (81%) with normal mucosa. Mild to moderate and severe duodenitis or villi atrophy was histologically confirmed in 65%, 26% and 8% of 212 patients respectively. The negative predictive value of a normal appearing duodenal mucosa was 19%. Additional tests confirmed celiac disease in 12 patients. Lactose malabsorption was present in 42%, bacterial overgrowth in 14%, and H. pylori infection in 28%. Colonoscopy performed in 92 patients revealed non specific colitis (25%), microscopic colitis (28%), Crohn's disease (1%), and diverticulosis (15%).

CONCLUSION

Duodenal biopsies revealed abnormalities in the majority of adults with chronic diarrhea and/or abdominal pain despite macroscopically normal gross findings. These results suggest that duodenal biopsies could be helpful in patients with chronic diarrhea and/or abdominal pain for the following work up.

Correlation between nasal mucociliary clearance time and gastroesophageal reflux disease: our experience on 50 patients

OBJECTIVES

It is increasingly suggested that gastroesophageal reflux disease (GERD) could play an important role in chronic rhinosinusitis. The aim of our study was to evaluate the nasal mucociliary clearance time in GERD patients and if any correlations could be assumed.

METHODS

Fifty GERD patients endoscopically diagnosed underwent an ear, nose and throat evaluation. The saccharin test and the 20-Item Sino-nasal Outcome Test (SNOT-20) were administered to 50 participants who correspond to our inclusion criteria. The saccharin test is a validated proof to verify the nasal mucociliary clearance time and the SNOT-20 is a disease-specific, health-related quality of-life questionnaire widely used for the assessment of rhinosinusitis.

RESULTS

Thirty-seven (74%) patients showed a significant increment in their saccharin test values in comparison with the others subjects (23.79+/-5.58 vs 8.15+/-2.06min; P=0.0001). This group of patients reported only typical gastroesophageal symptoms (GES) without any other complaint. Gastroesophageal endoscopic findings revealed some interesting and unexpected results in this subgroup. The remainder of patients considered (13/50; 26%) showed normal values for nasal mucociliary clearance time and they referred only typical extraesophageal symptoms (EES). In any case and in both groups rhinosinusitis complaints were present. The SNOT-20 test results were normal in all patients even if a significant difference for GES group could be highlighted (19.3 vs 7.4; P<0.005).

CONCLUSION

This study supports the assumption of possible and important correlations between nasal mucociliary clearance time and GERD. GERD could be an altering factor for nasal function also in absence of laryngo-pharyngeal symptoms although to verify this interesting hypothesis more validated data are necessary.

OLGA gastritis staging in young adults and country-specific gastric cancer risk

Geographical differences have been shown in the clinical outcomes of Helicobacter pylori-associated gastritis phenotypes and in gastric cancer risk. This study tested whether the Operative Link on Gastritis Assessment (OLGA) staging correlated with gastric cancer risk in populations from 3 continents. Mapped gastric biopsies were obtained from 316 dyspeptic adults aged less than 41 years from 8 geographic areas that differed in gastric cancer risk. Gastric atrophy was assessed according to internationally validated criteria. Gastritis stage was established according to the OLGA staging system. The most prevalent gastritis stages were 0 to II, which included all subjects entered from Chile, Germany, India, Italy, and Thailand. Gastritis Stages III and IV were limited to the Chinese and Korean populations. Indians had a high prevalence of H pylori infection without high-stage gastritis. In populations at different cancer risk, the gastritis OLGA stage mirrored the gastric cancer incidence. Gastritis staging identifies a subgroup of higher-risk patients.

Gastritis, dyspepsia and peptic ulcer disease

Peptic ulcer disease remains a common problem and it most frequently due to the presence of an Helicobacter pylori infection or use of non-steroidal anti-inflammatory drugs (NSAIDs). Dyspepsia is neither sensitive or specific for diagnosing peptic ulcer disease. The approach to patients with dyspepsia is to arrive at a definitive diagnosis without unnecessary exposure to invasive or costly diagnostic procedures. Non-invasive testing is preferred with endoscopy being reserved for those with alarm markers or above a specified age (e.g., 55 years in Western countries). Patients negative for H. pylori infection should receive an empiric trial of acid suppression for 4 to 8 weeks and if beneficial it can be continued.

Helicobacter pylori may play a contributory role in the pathogenesis of primary sclerosing cholangitis

Helicobacter pylori (H. pylori) DNA has been identified in human livers and has been implicated in chronic liver disease and liver cancer. To better understand the role of H pylori in primary sclerosing cholangitis (PSC), 25 patients with end-stage PSC and 31 controls were studied. Genomic DNA was extracted from microdissected hilar hepatic ducts of liver explants and was amplified for H pylori DNA. Serum was tested for H pylori antibodies. Helicobacter DNA was detected in 9 of the 56 (16%) patients by 16SrRNA PCR (an additional case [for a total of 18%] was antibody positive). Seven of the 9 cases identified by polymerase chain reaction were positive for the CagA gene, confirming they were H pylori. Seven of the 25 (28%) patients with PSC and 3 of the 31 (9.7%) controls were positive for Helicobacter (P=.087). H pylori DNA was detected in microdissected hilar biliary epithelium in more PSC patients than controls, supporting the hypothesis that bile reflux from the duodenum into the biliary tract might carry H pylori organisms into the proximal biliary system, possibly contributing to PSC development and/or progression in some patients.

Reflux symptoms in professional opera choristers

BACKGROUND AND AIMS

A specific, occupation-related susceptibility of professional singers to experience gastroesophageal reflux was hypothesized. We investigated the prevalence of gastroesophageal reflux symptoms in a series of professional opera choristers in comparison with a general population sample.

METHODS

A total of 351 professional opera choristers from well-known chorus in different Italian regions were identified and a sample of 578 subjects residing in the same areas with a similar distribution in age and sex was selected. Reflux symptoms in the year preceding the survey together with selected individual characteristics and lifestyle habits were investigated in both study groups through a structured questionnaire. Prevalence rate ratios, adjusted for sex, age, body mass index, smoking status, alcohol consumption, and other confounding factors, were computed.

RESULTS

Opera choristers reported a statistically significant higher prevalence of heartburn, regurgitation, cough, and hoarse voice than the population sample, with adjusted prevalent rate ratios of 1.60 (95% confidence interval [CI], 1.32-1.94), 1.81 (95% CI, 1.42-2.30), 1.40 (95% CI, 1.18-1.67), and 2.45 (95% CI, 1.97-3.04), respectively. Regurgitation appeared to be associated consistently with the cumulative lifetime duration of singing activity (P = .04) and with the weekly duration of singing activity (P = .005) when different multivariate models were applied.

CONCLUSIONS

Opera choristers reported a higher prevalence of reflux symptoms than the population sample. Future studies will be needed to clarify whether gastroesophageal reflux in professional opera choristers is stress-induced and therefore may be considered as a work-related disease.

Epidemiology of Helicobacter pylori Infection

This review summarizes epidemiologic studies published between April 2004 and March 2005. DNA of Helicobacter pylori was detected in river water, but the culture was unsuccessful. H. pylori infection was associated with Shigella infection. Despite many studies, predominant infection routes of H. pylori have not yet been clearly identified. In some limited populations in developing countries, H. pylori infection was rare or with strange distributions. Trials to reduce the H. pylori infection rate were performed including H. pylori eradication in total family units and fly control. The hypothesis of a causal role of Helicobacter species and H. pylori infection in cancer of the hepatobiliary tract was indeed confirmed.

Is there anything to the reported association between Helicobacter pylori infection and autoimmune thyroiditis?

Higher serological prevalence rates of Helicobacter pylori (Hp) infection have been reported in patients with autoimmune thyroiditis (AT), and it has been suggested that monoclonal antibodies against Cag-A positive Hp strains can cross-react with follicular cells of the thyroid gland. We studied the prevalence of AT and thyroid functional status in patients who underwent gastroscopy for dyspeptic symptoms. Patients were tested for TSH, free thyroid hormones, and antithyroglobulin and antithyroperoxidase antibodies (ATPO). Hp positivity was determined using urea breath test (UBT). Serum samples from 302 patients (59.9% women) were evaluated. One hundred ninety-one subjects (63.2%) were Hp-negative, and 111 of 302 (36.8%) were Hp-positive. Forty-three of 191 Hp-negative patients (22.5%; 95% CI, 17.1-29.0%) had an increase of either antibody, compared to 30 of 111 (27.0%; 95% CI, 19.6-36.0%) Hp-positive patients (P = 0.40). Similar results were obtained using positivity for both antibodies (7.3 vs. 7.2%; P = 1) or for ATPO (18.8 vs. 21.6%; P = 0.54). The prevalences of hypothyroidism (4.7 vs. 5.5%) or hyperthyroidism (5.8 vs. 5.5%) were also similar (P = 0.95). Hormonal levels were not different in the two groups (P > 0.22 in all cases). The previously reported association between AT and Hp infection was not observed in our study. Infection by Hp does not appear to increase the risk of AT in individuals with dyspeptic symptoms, and screening for this condition in patients with a positive UBT is not indicated.

Twice daily (mid-day and evening) quadruple therapy for H. pylori infection in the United States

BACKGROUND

Quadruple therapy provided inadequate eradication rate when given twice-a-day at breakfast and evening meals.

AIM

To test twice daily (mid-day and evening) quadruple therapy for Helicobacter pylori eradication.

METHODS

This was a single-centre pilot study in which H. pylori-infected (positive histology and culture and RUT) patients were given 2 x 250 mg of metronidazole and 2 x 250 mg of tetracycline, two Pepto-Bismol tablets, plus one 20 mg rabeprazole tablet twice-a-day for 14 days. H. pylori status was confirmed 4 or more weeks after the end of therapy.

RESULTS

Thirty-seven patients including 3 with peptic ulcer disease, 19 asymptomatic infected, 4 GERD, and 11 with NUD. Mid-day quadruple therapy was successful in 92.3% (95% CI: 79-98%) including 96.2% of those with metronidazole-susceptible strains, and in 83.3% (10/12) of those with metronidazole-resistant H. pylori. Compliance was 100% by pill count except in one individual who stopped medication after 12 days because of side-effects and who failed therapy. Moderate or greater side-effects were experienced by five patients.

CONCLUSION

Twice-a-day, mid-day, quadruple therapy proved effective using the combination of bismuth subsalicylate and rabeprazole instead of bismuth subcitrate and omeprazole. Detailed studies of different formulations (e.g. 2 x 250 mg versus 1 x 500 mg of metronidazole or tetracycline) and timing of administration (breakfast and evening meal versus mid-day and evening meals) may result in significant improvements in H. pylori eradication regimens.

Ulcers and gastritis

Significant advances continue to be made in the area of gastritis and ulcer disease. Studies to identify the most appropriate use of capsule endoscopy have now confirmed that it is superior to other methods for identifying small-bowel mucosal pathology and sites of obscure gastrointestinal bleeding. It has increasingly been recognized that the complications of ulcer disease are secondary to the use of nonsteroidal anti-inflammatory drugs (NSAIDs) and to interactions between NSAIDs and Helicobacter pylori. Effective prophylaxis for NSAID ulcers in H. pylori-negative individuals continues to be a challenge, as it has become clear that conclusions from studies focusing on "endoscopic ulcers" in patients whose H. pylori status was unknown provided a false sense of security. The concept of multifocal atrophic gastritis has been challenged. The precursor lesion to gastric cancer now appears to be a sheet of pseudopyloric metaplasia advancing into the gastric body with islands of intestinal metaplasia embedded within it. Multifactorial models such as those proposed for understanding periodontal disease, including the organism, environmental factors, and host factors, appear particularly applicable to understanding the pathogenesis of H. pylori-associated gastric cancer.

High-level beta-lactam resistance associated with acquired multidrug resistance in Helicobacter pylori

Four clinical Helicobacter pylori isolates with high-level resistance to beta-lactams exhibited low- to moderate-level resistance to the structurally and functionally unrelated antibiotics ciprofloxacin, chloramphenicol, metronidazole, rifampin, and tetracycline. This pattern of multidrug resistance was transferable to susceptible H. pylori by natural transformation using naked genomic DNA from a clinical multidrug-resistant isolate. Acquisition of the multidrug resistance was also associated with a change in the genotype of the transformed multidrug-resistant H. pylori. DNA sequence analyses of the gene encoding penicillin binding protein 1A (PBP 1A) showed 36 nucleotide substitutions resulting in 10 amino acid changes in the C-terminal portion (the putative penicillin binding domain). Acquisition of beta-lactam resistance was consistently associated with transfer of a mosaic block containing the C-terminal portion of PBP 1A. No changes of genes gyrA, rpoB, rrn16S, rdxA, and frxA, and nine other genes (ftsI, hcpA, llm, lytB, mreB, mreC, pbp2, pbp4, and rodA1) encoding putative PBPs or involved in cell wall synthesis were found among the transformed resistant H. pylori. Antibiotic accumulations of chloramphenicol, penicillin, and tetracycline were all significantly decreased in the natural and transformed resistant H. pylori compared to what was seen with susceptible H. pylori. Natural transformation also resulted in the outer membrane protein profiles of the transformed resistant H. pylori becoming similar to that of the clinical resistant H. pylori isolates. Overall, these results demonstrate that high-level beta-lactam resistance associated with acquired multidrug resistance in clinical H. pylori is mediated by combination strategies including alterations of PBP 1A and decreased membrane permeability.

Detection of Chlamydiae pneumoniae but not Helicobacter pylori DNA in atherosclerosis plaques

Chronic infections have been associated with cardiovascular disease. We used bacterial culture, polymerase chain reaction (PCR), and immunohistochemical staining with anti-vacA and anticagA antibodies to search for Helicobacter pylori and Chlamydiae pneumoniae in atherosclerotic plaques obtained at endarterectomy. Serum IgG antibodies to H. pylori and C. pneumoniae were also determined. Thirty-two patients were enrolled. Anti-H. pylori and anti-C. pneumoniae IgG were present in 72% and 81%, respectively. Culture and PCR for H. pylori of vessel walls and plaques were negative. Atherosclerotic plaque and normal vessel sections from H. pylori-negative and- positive patients showed reactivity with anti-vacA and anti-cagA antibodies. C. pneumoniae DNA was amplified in three atherosclerotic lesions. These findings suggest that the association between H. pylori infection and atherosclerosis does not result from continuing direct effects of H. pylori antigens in the vessel walls. Antigens within vessel atherosclerotic plaques cross-react with H. pylori virulence factors and could act as cofactors in determining instability for the atherosclerotic plaques.

Risk Factors Associated with Helicobacter pylori Infection among Children in a Defined Geographic Area

Factors influencing the pattern of Helicobacter pylori infection among children living in adjacent urban and rural areas of northern Sardinia, Italy, were compared. The seroprevalence of H. pylori infection was 22% (625 of 2810 children) in the study population and was significantly higher among children in rural areas (37%) than in urban areas (13%) (odds ratio [OR], 3.8; 95% confidence interval [CI], 3.2-4.7; P<.005). This difference was consistent within each age group. In rural areas, children who had dogs were at greatest risk for H. pylori infection (OR, 1.8; 95% CI, 1.3-2.6; P<.05). No association was seen between H. pylori seropositivity and a history of breast-feeding. Urban children attending day care centers had a higher prevalence of infection (17%) than did those who never attended (12%) (OR, 1.5; 95% CI, 1.1-2.0; P<.05). The epidemiology of H. pylori infection is complex; even within the same geographic area, different factors influence acquisition of H. pylori infection.

Helicobacter infection in patients with HCV-related chronic hepatitis, cirrhosis, and hepatocellular carcinoma

Chronic hepatitis may progress to cirrhosis and hepatocellular carcinoma (HCC). HCC represents one of the most common human cancers. Incidence rates for this tumor vary widely on a worldwide, suggesting that environmental factors such as infectious microorganisms, carcinogens, or nutrition play a role in its pathogenesis. Several Helicobacter spp. colonize the liver of animals and induce hepatitis. The aim of this study was to determine whether Helicobacter infection was associated with HCV-related liver diseases in humans. Liver tissue samples, including biopsy and surgically excised tissues, were collected from patients positive for hepatitis C viruses (HCV) RNA in the serum. Genomic DNA was extracted from sections of formalin-fixed paraffin-embedded tissues by using the QIAamp Tissue Kit and subjected to polymerase chain reaction (PCR) analysis using two sets of Helicobacter-specific 16S ribosomal RNA primers. To identify positive samples for H. pylori, a set of primers specific for a conserved region in the H. pylori vacA gene were also used. The patients' H. pylori status was determined by ELISA. Forty-one patients (mean age 54.9, range 19-78 years; 24 men) were studied. Thirty patients had chronic viral hepatitis (CH) without (N = 18) or with (N = 12) cirrhosis (CIR), and 11 patients had HCC. Anti-H. pylori IgG was detected in 54%. The expected 422- and 210-bp fragments of Helicobacter 16S rRNA were amplified from 27% of liver samples, including 17% of CH-CIR and 55% of HCC (P = 0.004). The vacA sequence was amplified in 10 of 41(24%) samples (27% of those with HCC). These data confirm the presence of H. pylori DNA sequences in human liver and suggest an association of Helicobacter spp. with HCV-related chronic liver diseases. Further studies are needed to ascertain whether Helicobacter spp. infection plays a role in the development of HCC.

Helicobacter infection in patients with HCV-related chronic hepatitis, cirrhosis, and hepatocellular carcinoma

Chronic hepatitis may progress to cirrhosis and hepatocellular carcinoma (HCC). HCC represents one of the most common human cancers. Incidence rates for this tumor vary widely on a worldwide, suggesting that environmental factors such as infectious microorganisms, carcinogens, or nutrition play a role in its pathogenesis. Several Helicobacter spp. colonize the liver of animals and induce hepatitis. The aim of this study was to determine whether Helicobacter infection was associated with HCV-related liver diseases in humans. Liver tissue samples, including biopsy and surgically excised tissues, were collected from patients positive for hepatitis C viruses (HCV) RNA in the serum. Genomic DNA was extracted from sections of formalin-fixed paraffin-embedded tissues by using the QIAamp Tissue Kit and subjected to polymerase chain reaction (PCR) analysis using two sets of Helicobacter-specific 16S ribosomal RNA primers. To identify positive samples for H. pylori, a set of primers specific for a conserved region in the H. pylori vacA gene were also used. The patients' H. pylori status was determined by ELISA. Forty-one patients (mean age 54.9, range 19-78 years; 24 men) were studied. Thirty patients had chronic viral hepatitis (CH) without (N = 18) or with (N = 12) cirrhosis (CIR), and 11 patients had HCC. Anti-H. pylori IgG was detected in 54%. The expected 422- and 210-bp fragments of Helicobacter 16S rRNA were amplified from 27% of liver samples, including 17% of CH-CIR and 55% of HCC (P = 0.004). The vacA sequence was amplified in 10 of 41(24%) samples (27% of those with HCC). These data confirm the presence of H. pylori DNA sequences in human liver and suggest an association of Helicobacter spp. with HCV-related chronic liver diseases. Further studies are needed to ascertain whether Helicobacter spp. infection plays a role in the development of HCC.

Genotypic characterization of clarithromycin-resistant Helicobacter pylori strains

Helicobacterpylori (Hp) resistance to clarithromycin, one of the antibiotics most used to eradicate infection, is connected with the presence of a point mutation on the level of adenine at position 2143 or 2144 of 23S rRNA.

AIM

The aim of the study is to evaluate of the presence of these mutation vs control clarithromycin resistant Hp strains present in North Sardinia; to verify the real association between the type of mutation and the resistance-level; to use easier molecular biology methods to quickly locate the resistance-associated mutations beginning with the bioptic material. The clarithromycin susceptibility of Hp isolates was tested by the E-test method (antibiotic assay). Genomic DNA of Hp strains was amplified using specific primers for the domain V. of ribosomic 23S rRNA and sequenced after the reaction with a primer within the fragment 23S. At the same time PCR-RFLP reliability was examined underlining the presence of these mutations with BsaI, BbsI, MboII restriction enzymes. Two mutations in 2143 (A- - G) and 2144 (A- - G) were found by domain V sequencing. The strains with mutation 2143 are characterized by a greater resistance level (MIC>64 g/ml) than those with mutation 2144 (MIC <64 g/ml). Restriction endonucleases BbsI and MboII recognise the site containing the mutation 2143 (A- - G), while BsaI recognise the mutation 2144 (A- - G). These methods might enable us to identify the presence of Hp directly from bioptic material and possible clarithromycin resistance and plan a suitable therapeutic strategy and consequently a better control of the infection.

Colloidal bismuth subcitrate-based twice-a-day quadruple therapy as primary or salvage therapy for Helicobacter pylori infection

OBJECTIVE

Helicobacter pylori (H. pylori) eradication rates in northern Sardinia using standard 1-wk triple therapies (i.e., a proton pump inhibitor and two antibiotics) are typically <60%, primarily because of antibiotic resistance. The aim of this study was to test b.i.d. quadruple therapy as primary and as salvage therapy in this population.

METHODS

This was a prospective, single center study of consecutive dyspeptic H. pylori-infected patients. Therapy consisted of omeprazole 20 mg, tetracycline 500 mg, metronidazole 500 mg, and bismuth subcitrate caplets 240 mg, all b.i.d. with the midday and evening meals for 14 days. H. pylori status was evaluated by 13C-urea breath test and histology before and 4-6 wk after therapy. Eradication was defined as no positive test.

RESULTS

We enrolled 118 consecutive dyspeptic patients (mean age 46 yr; 73 men, including 15 with peptic ulcer disease). Of the patients, 42 (38%) had failed prior therapy: twice in 21 cases, three times in 12, and four or more times in nine. The intention-to-treat cure rate was 95% (110 of 116) (95% CI = 90-98%) overall, and 98% per protocol, irrespective of diagnosis, age, prior treatment failure, or smoking status. Moderate or severe side effects were experienced by only 5% of patients.

CONCLUSIONS

Bismuth subcitrate-based b.i.d. quadruple therapy was an excellent primary and salvage therapy and should be considered as first line therapy.

Genomic instability in chronic viral hepatitis and hepatocellular carcinoma

Chronic hepatitis may progress to cirrhosis and hepatocellular carcinoma (HCC). Progressive accumulation of mutations and genomic instability in chronic viral hepatitis might flag an increased risk of HCC development. Genomic instability at dinucleotide microsatellite loci in chromosomes 2, 13, and 17 and at 2 mononucleotide repeat loci was examined in liver tissues from 41 patients, including 30 without HCC (18 patients with chronic hepatitis and 12 with cirrhosis) and 11 with HCC. Genomic instability was detected in 51% of the 41 cases. Allelic imbalance at informative dinucleotide loci occurred in 37% of the cases. In 14 cases (34%), allelic imbalance was detected in chronic hepatitis or cirrhosis without HCC. Allelic imbalance at the chromosome 13 locus was detected in 50% of the cases of chronic hepatitis C. Allelic imbalance at the TP53 chromosome locus and/or at the chromosome 13 locus was significantly more frequent than alterations at the chromosome 2 locus (P =.026). Low-level microsatellite instability was found in 20% of all cases examined and high-level microsatellite instability in 3 patients (7.5%), including 2 cases of chronic hepatitis and 1 case of cirrhosis. Our results show that allelic imbalance occurs frequently in hepatitis-related HCC as well as in chronic hepatitis in patients without HCC. Allelic imbalance at the D13S170 chromosome 13 locus (13q31.2) occurs frequently in chronic hepatitis, suggesting that genomic alterations affecting the long arm of chromosome 13 might be used to monitor the natural progression of chronic hepatitis-associated liver carcinogenesis.

Isolation of Helicobacter pylori from sheep-implications for transmission to humans

OBJECTIVES

When and how Helicobacter pylori (H. pylori) originally entered the human population as well as how the infection is transmitted in different communities is unknown. We previously showed that Sardinian shepherds had almost a 100% prevalence of H. pylori and that the prevalence was higher than that of their same-household siblings.

AIM

To examine whether H. pylori infection might be transmitted from sheep.

METHODS

Milk and gastric tissue were cultured and analyzed by PCR amplification using three sets of primers Helicobacter genus-specific 16S rRNA and two sets of primers specific for H. pylori vacA gene.

RESULTS

Helicobacter DNA was demonstrated in 60% (38/63) of milk samples and in 30% (6/20) of sheep tissue samples. H. pylori vacA gene was amplified in five of 38 milk samples, and in two of six sheep tissue samples respectively. H. pylori were cultured from sheep milk and tissue samples and confirmed as H. pylori on the basis of colony morphology, positive biochemical reactions, and negative Gram stain. Sequence analysis of 16S rRNA PCR products from these isolates demonstrated 99% identity with H. pylori.

CONCLUSIONS

Together, the presence of H. pylori in sheep stomach in the absence of associated gastritis and recovery of H. pylori from sheep milk and gastric tissue suggest that sheep may be a natural host for H. pylori.

Characterization of a culture method to recover Helicobacter pylori from the feces of infected patients

BACKGROUND

Helicobacter pylori is difficult to culture from stool. Multiple efforts from multiple laboratories have been unsuccessful, and the optimal conditions to recover H. pylori from stool are still not known. Recovery of H. pylori from feces of infected individuals is important for the performance of molecular epidemiological investigations, especially in children, where their symptoms do not warrant endoscopy to recover the organism.

METHODS

Fresh fecal specimens (noncathartic) were obtained from 19 known H. pylori-infected patients and were processed to recover the organism. Fresh fecal specimens (noncathartic) were also obtained from three known H. pylori-negative individuals (controls) to determine whether H. pylori could be isolated from stools seeded with known concentrations of the organism. Treatment of the fecal suspensions with cholestyramine, a basic anion exchange resin that binds bile acids, was used in an attempt to enhance recovery of H. pylori by sequestering bile acids that are inhibitory to H. pylori growth. H. pylori was identified based on colony morphology, cell morphology, Gram's stain, biochemical reactions, and polymerase chain reaction for two H. pylori genes.

RESULTS

Among 19 patients, H. pylori was cultured at least once from 3 and three times from 2 (5 of 19). Feces that were seeded with H. pylori and obtained from three H. pylori-negative volunteer controls yielded positive recovery in all instances.

CONCLUSION

We have confirmed that it is possible to culture H. pylori from human stool, but the procedure for optimal recovery has still not been defined.

Diabetes mellitus and Helicobacter pylori infection

Alterations of glucose metabolism in diabetes have been suggested as promoting Helicobacter pylori colonization. We performed a cross-sectional sero-prevalence study of diabetic patients (insulin-dependent, or type 1, and non-insulin-dependent, or type 2, diabetes mellitus) with H. pylori and compared them with a control group. Consecutive diabetic outpatients aged 12 to 75 y and with disease duration of greater than 1 y were enrolled. Helicobacter pylori status was evaluated by using an enzyme-linked immunosorbent assay for anti-H. pylori immunoglobulin G. Demographic data were obtained from each individual, and socioeconomic class was assessed by occupation and education level. A total of 891 individuals participated (240 with type-2 diabetes, 145 with type-1 diabetes, and 506 control subjects). After controlling for age, there was no significant difference in the prevalence of H. pylori infection in any age group. In fact, the prevalence of H. pylori was numerically higher among children in the control group than among children with type-1 diabetes (25% versus 9%, respectively; P = 0.1). Previous associations of H. pylori and diabetes may have arisen from failure to consider socioeconomic status or age. Because childhood is the most common period for acquisition of H. pylori infection, the higher prevalence of infection among the normal children as opposed to those with type-1 diabetes confirms the lack of an association.

Pathogenesis of duodenal ulcer disease: the rest of the story

Although several duodenal ulcer disease-specific abnormalities in gastric function have been described (e.g. exaggerated gastrin releasing peptide-stimulated acid secretion and an abnormal sensitivity of the parietal cells to gastrin), none has withstood careful examination. We describe here the critical nature of the duodenal acid load in precipitating and washing out bile salts, which inhibit the growth of Helicobacter pylori (H. pylori) in the development of duodenal ulcer disease. The risk of duodenal ulcer is enhanced by infection with proinflammatory H. pylori (e.g. with an intact cag pathogenicity island). Progressive damage to the duodenum promotes gastric metaplasia, resulting in sites for H. pylori growth and more inflammation. This cycle results in an increasing inability of the duodenal bulb to neutralize acid entering from the stomach until changes in duodenal bulb structure and function are sufficient for an ulcer to develop. Cure of the H. pylori infection results in a sustained fall in duodenal acid load as well as a marked (and continuing) reduction in inflammation, which results in the cure of chronic ulcer disease.

Effect of pretreatment antibiotic resistance to metronidazole and clarithromycin on outcome of Helicobacter pylori therapy: a meta-analytical approach

Our purpose was to define the effect of pretreatment Helicobacter pylori resistance to metronidazole or to clarithromycin on the success of antimicrobial therapy. We used 75 key words to perform a literature search in MEDLINE as well as manual searches to identify clinical treatment trials that provided results in relation to H. pylori susceptibility to metronidazole and clarithromycin or both during the period 1984-1997 (abstracts were not included). Meta-analysis was done with both fixed- and random-effect models; results were shown using Galbraith's radial plots. We identified 49 papers with 65 arms for metronidazole (3594 patients, 2434 harboring H. pylori strains sensitive to metronidazole and 1160 harboring resistant strains). Metronidazole resistance reduced effectiveness by an average of 37.7% (95% CI = 29.6-45.7%). The variability in the risk difference for metronidazole was 122.0 to -90.6 and the chi-square value for heterogeneity was significant (P<0.001). Susceptibility tests for clarithromycin were performed in 12 studies (501 patients, 468 harboring H. pylori strains sensitive to clarithromycin and 33 harboring resistant strains). Clarithromycin resistance reduced effectiveness by an average of 55% (95% CI = 33-78%). We found no common factors that allowed patients to be divided into subgroups with additional factors significantly associated with resistance. In conclusion, metronidazole or clarithromycin pretreatment resistant H. pylori are the main factors responsible for treatment failure with regimens using these compounds. If H. pylori antibiotic resistance continues to increase, pretherapy antibiotic sensitivity testing might become necessary in many regions.