Helicobacter pylori seroprevalence in patients with cirrhosis of the liver and hepatocellular carcinoma

Eradication of Helicobacter pylori alleviates lipid metabolism deterioration: a large-cohort propensity score-matched analysis

Background

The impact of Helicobacter pylori (H. pylori) eradication on metabolism of lipid and the potential predictor of such changes remain unclear.

Methods

This study retrospectively included subjects who underwent at least two ¹³C urea breath tests between 2015 and 2019 at Wuhan Union Hospital. Based on two H. pylori¹³C examination results, subjects were divided into propensity score-matched persistently negative (HPN), persistently positive (HPP), and eradication (HPE) groups. The changes in lipid measurements from before to after H. pylori eradication, including high-density lipoprotein (HDL), low-density lipoprotein (LDL), total cholesterol, and triglycerides, were compared within and between groups. Forty-two candidate factors were tested for their ability to predict lipid metabolism changes after H. pylori eradication.

Results

After propensity score matching, 3412 matched cases were analyzed. Within-group comparisons showed significantly decreased HDL (P <  0.001) and increased LDL (P <  0.001) at the second examination in both the HPE and HPP groups. Between-group comparisons showed that the HDL decrease of the HPE group was significantly larger and smaller when compared with the HPN (P = 0.001) and HPP (P = 0.004) group, respectively. Uni- and multivariate analyses showed that low diastolic blood pressure (DBP) (P = 0.002) and high mean platelet volume (MPV) (P = 0.001) before eradication were associated with increased HDL after eradication. Low total protein (TP) (P <  0.001) was associated with decreased LDL after eradication.

Conclusions

Compared with sustained H. pylori infectious states, H. pylori eradication alleviated the lipid metabolism deterioration but did not restore it to the uninfected level within 1.5 years after eradication. Patients with low DBP, high MPV, and low TP may reap a greater lipid-metabolism benefit from H. pylori eradication.

Coinfection of Helicobacter pylori and Hepatitis C Virus in the Development of Hepatocellular Carcinoma: A Systematic Review and Meta-Analysis

Background

The relationship between Helicobacter pylori (H. pylori) and hepatocellular carcinoma (HCC) was firstly proposed in 1994 after Ward et al demonstrated the role of Helicobacter hepaticus in the development of HCC in mice. Studies also investigated the role of hepatitis B virus (HBV) and hepatitis C virus (HCV) coexisting with H. pylori in causing HCC. A causal relationship was never confirmed, and the relationship remains controversial. This meta-analysis aimed to summarize the research on this topic and investigate if a relationship exists between H. pylori infection and the development of HCC and if the presence of HCV and HBV along with H. pylori plays a role in liver carcinogenesis.

Methods

Following PRISMA guidelines, we performed a systematic review of all relevant studies published in the literature using the keywords “Helicobacter pylori” and “hepatocellular carcinoma” on major literature databases, including PubMed, EMBASE, Web of Science, and Cochrane controlled trials register. A total of 656 research studies were identified between 1994 and 2020. Of those, 26 qualified under our selection criteria. Patients who were positive for HCC were classified as cases and those who did not have HCC were classified as controls. The H. pylori status and HCV status, if available, were identified for both groups. Statistical analysis was carried out by a biostatistician according to the Cochrane reviewer’s handbook.

Results

Out of the 26 studies included in the final analysis, 13 were retrospective case-control studies, 11 were cross-sectional studies, and two were prospective case-control and cohort studies. Overall, the prevalence of H. pylori infection was 64.78% (561 of 866) amongst HCC cases and 47.92% (1,718 of 3,585) in the non-HCC control group. The summary odds ratio (OR) for the association of H. pylori infection with the risk for HCC (using the random-effects model, which accounted for the heterogeneity across the 26 studies) was determined to be 4.75 (95% confidence interval (CI): 3.06 - 7.37, I² = 63%). We also performed a subgroup analysis to determine the odds of developing HCC in the presence of H. pylori and HCV coinfection. The summary OR of it was 12.76 (95% CI: 4.13 - 39.41, I² = 78%). The summary OR for the risk of developing HCC in the presence of HCV infection without H. pylori infection was 2.21 (95% CI: 0.70 - 6.94, I² = 79%). Whereas, the odds of developing HCC in the presence of only H. pylori infection without HCV was found to be 0.54 (95% CI: 0.11 - 2.63, I² = 80%). There was inconsistency in the data presented in some studies regarding HCV infection status. Since data were extracted from different study designs, subgroup analysis by study design was performed which showed no significant difference between the study groups (P = 0.5705).

Conclusion

This meta-analysis demonstrates a positive association between H. pylori infection and the development of HCC. There is a significantly higher risk of developing HCC in the presence of HCV infection along with H. pylori. Further prospective cohort studies are needed to prove the causal relationship, especially in cases of HBV and HCV coinfection, and cirrhotic patients.

Helicobacter pylori Infection and Psoriasis: A Systematic Review and Meta-Analysis

Background and Objectives: To perform a systematic review and meta-analysis with the aim of determining the relationship between H. pylori infection and psoriasis. Methods: Pubmed, Embase, China National Knowledge Infrastructure (CNKI), and Web of Science were searched for articles published up to July, 2019. Review Manager 5.3 and Stata 12.0 were used for statistical analyses. Results: The initial database search resulted in 204 articles. Through exclusion and screening, 11 studies involving a total of 1741 participants were finally included in this meta-analysis. The odds ratio (OR) of H. pylori infection rate in the psoriasis group was significantly higher than that in the control group (OR = 1.19, 95% CI 1.15–2.52, P = 0.008). Subgroup analysis showed that no significant difference was detected between the Asia group and the Europe group. As for the methods of H. pylori detection, a statistically significant increase of H. pylori infection in the IgG ELISA test group was detected, compared with the urea breath test group. In addition, analysis based on the severity of psoriasis showed a statistically significant increase of H. pylori infection in moderate and severe psoriasis patients (OR = 2.27; 95% CI: 1.42–3.63, I² = 27%), but not in the mild psoriasis patients (OR = 1.10; 95% CI: 0.79–1.54, I² = 0%). Conclusion: H. pylori infection is associated with psoriasis, and psoriasis patients with H. pylori infection have higher Psoriasis Area and Severity Index (PASI) scores. The findings are of considerable significance for the clinical practices.

Association between proton pump inhibitors and the risk of hepatocellular carcinoma

BACKGROUND

Proton pump inhibitor (PPI) use has been reported to be associated with liver damage and might possibly be carcinogenic.

AIMS

We examined whether long-term PPI use increases the risk of hepatocellular carcinoma (HCC) in patients without viral hepatitis B or C.

METHODS

We conducted a nested case-control study in a cohort of patients without viral hepatitis in Taiwan from 2000 to 2013. In total, 29 473 HCC cases and 294 508 matched controls were included. Moreover, we identified prescriptions for PPI and durations between the PPI index date and cancer diagnosis date (or the corresponding date in controls).

RESULTS

The adjusted odds ratio (AOR) for HCC associated with PPI use was 2.86 (95% confidence interval [CI], 2.69-3.04). Considering the use of PPIs determined according to cumulative defined daily dose (cDDD) subgroups, a dose-response effect was observed in patients exposed to 29-180, 181-240, 241-300, and 300+ cDDDs of PPIs. The AORs were 2.74 (95% CI, 2.57-2.93), 2.98 (95% CI, 2.50-3.56), 3.23 (95% CI, 2.59-4.02), and 3.43 (95% CI, 2.94-4.00) in the 29-180, 181-240, 241-300, and 300+ cDDD groups, respectively, compared with the 0-28 cDDD group. A sensitivity analysis revealed a consistent association between PPI use and the risk of HCC in subpopulations stratified by risk factors associated with HCC.

CONCLUSIONS

This observational study demonstrated that PPIs might increase the risk of HCC.

NAFLD, Helicobacter species and the intestinal microbiome

Non-alcoholic fatty liver disease (NAFLD) has become the most common chronic liver disease worldwide. It is well-accepted that gut dysbiosis is associated with NAFLD, however, there is some conflicting evidence regarding the nature of these alterations. Infection with Helicobacter species, mainly H. pylori, has also been associated with increased NAFLD risk, however, some studies have failed to reproduce this finding. Further studies including large study samples and standardised procedures for microbiota analyses, H. pylori detection and NAFLD diagnostic criteria, are required. The mechanisms involving Helicobacter species and the intestinal microbiome in NAFLD pathogenesis appear to be part of the multiple-hit theory, in which increased intestinal permeability, inflammatory responses, altered choline, bile acids and carbohydrate metabolism, production of short-chain fatty acids, urea cycle and urea transport systems, altered maintenance of hepatic γδT-17 cells, insulin resistance, hormones secreted by the adipose tissue, metabolic hormones, bacterial metabolites and Helicobacter toxins, are all implicated.

Interplay between viruses and bacterial microbiota in cancer development

During the last few decades we have become accustomed to the idea that viruses can cause tumors. It is much less considered and discussed, however, that most people infected with oncoviruses will never develop cancer. Therefore, the genetic and environmental factors that tip the scales from clearance of viral infection to development of cancer are currently an area of active investigation. Microbiota has recently emerged as a potentially critical factor that would affect this balance by increasing or decreasing the ability of viral infection to promote carcinogenesis. In this review, we provide a model of microbiome contribution to the development of oncogenic viral infections and viral associated cancers, give examples of this process in human tumors, and describe the challenges that prevent progress in the field as well as their potential solutions.

The Association between Helicobacter pylori Infection and Chronic Hepatitis C: A Meta-Analysis and Trial Sequential Analysis

Purpose. Helicobacter pylori is a common gastric disease-inducing pathogen. Although an increasing number of recent studies have shown that H. pylori is a risk factor for liver disease, the potential association between H. pylori infection and chronic hepatitis C still remains controversial. The aim of our meta-analysis was to evaluate a potential association between H. pylori infection and chronic hepatitis C. Methods. We searched the PubMed, Embase, CNKI, Web of Science, and the Cochrane Central Register of Controlled Trials (CENTRAL) databases between January 1, 1994, and May 1, 2015. Results. This study included a total of 1449 patients with chronic hepatitis C and 2377 control cases. The prevalence of H. pylori was significantly higher in patients with chronic hepatitis C than in those without chronic hepatitis C. The pooled odds ratio was 2.93. In a subgroup analysis, the odds ratios were 4.48 for hepatitis C virus- (HCV-) related cirrhosis and 5.45 for hepatocellular carcinoma. Conclusion. Our study found a strong association between H. pylori and chronic hepatitis C, particularly during the HCV progression stage; thus, we recommend active screening for H. pylori in patients with chronic hepatitis C.

Impact of Helicobacter pylori on the growth of hepatic orthotopic graft tumors in mice

Helicobacter pylori is a well-known causative organism of chronic gastric diseases and has been found in many hepatic carcinoma samples. To explore the expression of apoptosis-related proteins and carcinoma development in H. pylori-infected livers, we utilized BALB/cAnSlac mice to establish an H. pylori-infected model by oral inoculation and orthotopic grafts of hepatic tumors by H22 cells, respectively. We found that H. pylori colonies could not be cultured from all liver and tumor samples. However, its 16S rRNA was detectable in 85.3% of livers and 66.7% of tumors in the infected mice. Inflammatory cells were observed and thinly distributed in the lobule portions of the liver, and H. pylori mainly existed in the infected hepatic sinusoids and the necrotic areas of the infected tumors. No significant difference was found in liver to body weight ratio between the infected and uninfected. Moreover, the pathological tumor difference was unremarkable between the two. The proliferating cell nuclear antigen (PCNA) and Bcl-2-associated X protein (Bax) expression in the infected tumors was significantly higher and lower, respectively, than those of the uninfected tumors. However, no significant difference in Bcl-2 (B-cell lymphoma 2) expression existed. The results indicate that H. pylori found in the livers which were infected by H. pylori oral inoculation could contribute to the infiltration of inflammatory cells in livers. Although H. pylori has no significant impact on the liver to body weight ratio or tumor Bcl-2 expression, it may upregulate PCNA expression and downregulate Bax expression, respectively. All our findings show that H. pylori may promote proliferation and inhibit apoptosis of tumor cells.

The relationship between Helicobacter pylori and cancer risk

OBJECTIVES

This study investigated the correlation between Helicobacter pylori (HP) and cancer risk. We compared the age, sex, and comorbidity of cancer patients both infected and not infected by HP.

METHODS

In this study, we compared a comparison cohort (N=24,088) and an HP cohort (N=6022), both taken from the NHI database. We performed a statistical analysis with the multivariable Cox proportional model to estimate the risk of developing cancer for a comparison and the HP cohort.

RESULTS

Our results showed that the proportion of peptic ulcers in the HP cohort was nearly 4 times higher than that in the comparison cohort. The HP cohort was significantly associated with increased colorectal (HR=1.73, 95% CI=1.08-2.77), stomach (HR=5.21, 95% CI=2.46-11.05) and pancreatic (HR=2.77, 95% CI=1.04-7.39) cancer risks compared to the comparison cohort. In addition, the cancer risk in the HP cohort was considerably higher than that in the comparison cohort when hypertension was absent in both cohorts.

CONCLUSIONS

In this study, we proposed a method to investigate the correlation between HP infection and cancer risk. We found that HP infection is associated with the development of colorectal, stomach, and pancreatic cancers, and could thus be an independent carcinogenic risk factor.

The effect of helicobacter pylori eradication on liver fat content in subjects with non-alcoholic Fatty liver disease: a randomized open-label clinical trial

BACKGROUND

The role of Helicobacter pylori (HP) in the pathogenesis of nonalcoholic fatty liver disease (NAFLD) is unclear.

OBJECTIVES

The aim of this study was to evaluate the effect of HP eradication on liver fat content (LFC), liver function tests (LFT), lipid profile, and homeostasis model assessment-IR (HOMA-IR) index in NAFLD.

PATIENTS AND METHODS

Dyspeptic patients with increased serum aminotransferase levels were enrolled in the study. The exclusion criteria were factors affecting serum aminotransferase or HP treatment strategy. Participants with persistent elevated serum aminotransferase level and ultrasound criteria for identification of fatty liver were presumed to have NAFLD. "NAFLD liver fat score" was used to classify NAFLD. Those with "NAFLD liver fat score" greater than -0.64 and positive results for urea breath test (UBT), were included. Lifestyle modification was provided to all participants. HP eradication was performed in intervention arm. LFC, fasting serum glucose (FSG), alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), triglyceride (TG), cholesterol (CHOL), high and low-density lipoprotein (HDL, LDL), and HOMA-IR were checked at baseline and after that, at intervals of eight weeks and twenty four weeks.

RESULTS

One hundred (49 males) patients with the mean age of 43.46 (± 11.52) were studied. Repeated measure ANOVA showed a significant reduction in LFC, anthropometric measurements, and laboratory parameters (except for HDL) in the both groups during the study; however, no significant difference was observed between the groups.

CONCLUSIONS

It seems that HP eradication per se might not affect LFC, LFT, lipid profile, and insulin resistance in dyspeptic NAFLD patients.

Role of Helicobacter pylori in patients with HCV-related chronic hepatitis and cirrhosis with or without hepatocellular carcinoma: possible association with disease progression

The discovery of Helicobacter hepaticus as a causal agent of hepatitis and hepatocellular carcinoma (HCC) in mice has stimulated interest in looking for Helicobacter species in human liver samples. In this study, we searched for association between H. pylori and HCV-related liver disease. Liver specimens were collected from eighty-five patients; they were divided into five different groups according to liver pathology (METAVIR system). Group I (the 1st control group) consisted of 16 patients with chronic hepatitis C without histological activity. Group II consisted of 25 patients with chronic active hepatitis C, Group III, 17 patients with HCV-related cirrhosis and Group IV, 16 patients with HCV-related cirrhosis and HCC. Group V (2nd control group) consisted of 11 patients suffering from gastro duodenal and gall bladder diseases but negative for HCV. All cases were tested by polymerase chain reaction on liver samples for the presence of H. pylori DNA Cag A gene. Routine biochemical, radiological and RT-PCR for HCV RNA were also performed for all cases. The positivity of H. pylori PCR CagA gene in liver tissue was directly proportional to the severity of liver pathology, this being 75%, 52.9% and 32% in groups IV, III and II, respectively, which was more significant than the 1st and 2nd control groups (P < 0.001). There was a significant difference between H. pylori PCR values when compared to METAVIR staging (F) in different groups (P = 0.001). Helicobacter pylori PCR (Cag A gene) was positive in about 28.2% cases of late fibrosis (F3 + F4) while positivity was (5.9%) in early fibrosis (F1 + F2) (P = 0.0001). There was significant difference between H. pylori PCR (Cag A gene) in liver tissue and METAVIR activity in different groups (P = 0.002) as most of H. pylori PCR-positive cases were METAVIR activity A1 and A2 (15.3% and 12.9%, respectively). There was no association between H. pylori PCR and quantitative HCV RNA (P = 0.531). Also there was no significant difference of Child-Pugh staging in the H. pylori PCR-positive group when compared to the negative group (P = 0.996). There may be an association between the presence of H. pylori (Cag A gene) in the liver and disease progression in HCV-related chronic hepatitis and cirrhosis with and without HCC.

Extragastrointestinal manifestations of Helicobacter pylori infection: facts or myth? A critical review

Helicobacter pylori (H. pylori) infection is reported to be associated with many extragastrointestinal manifestations, such as hematological diseases [idiopathic thrombocytopenic purpura (ITP) and unexplained iron deficiency anemia (IDA)], cardiovascular diseases (ischemic heart diseases), neurological disorders (stroke, Parkinson's disease, Alzheimer's disease), obesity and skin disorders. Among these, the best evidence so far is in ITP and unexplained IDA, with high-quality studies showing the improvement of IDA and ITP after H. pylori eradication. The evidence of its association with coronary artery disease is weak and many of the results may be erroneous. The role of H. pylori infection in affecting serum leptin and ghrelin levels has attracted a lot of attention recently and available data to date have been conflicting. There have also been many uncontrolled, small sample studies suggesting an association between H. pylori infection and neurological disorders or chronic urticaria. However, more studies are required to clarify such proposed causal links.

Helicobacter pylori accelerates hepatic fibrosis by sensitizing transforming growth factor-β1-induced inflammatory signaling

Our earlier report has shown that Helicobacter pylori promoted hepatic fibrosis in a murine model. Herein, in order to elucidate the mechanism by which H. pylori accelerate liver fibrosis, the authors investigated the changes in expression levels of mitogen-activated protein kinases (MAPKs), p53-related proteins, antioxidants, and proinflammatory cytokines in liver samples. H. pylori infection enhanced CCl4-induced MAP kinase activation and p53 signaling pathway as well as Bax- and proliferating-cell nuclear antigen expressions, whereas H. pylori alone induced neither of these expressions nor hepatic fibrosis. Moreover, mRNA expressions of inflammatory cytokines, glutathione peroxidase expression, and the proliferative index were strongly augmented in livers of the H. pylori with CCl4 treatment group compared with those of the CCl4-alone treatment group, whereas there was no difference in apoptotic index between the two groups. Interestingly, H. pylori treatment increased the number of α-fetoprotein-expressing hepatocytes independently of CCl4 intoxication. In vitro analyses, using an immortalized rat hepatic stellate cell (HSC) line, revealed that H. pylori lysates increased the proliferation of HSCs, which was boosted by the addition of transforming growth factor-beta1 (TGF-β1). Furthermore, the treatment of H. pylori lysates promoted the translocation of nuclear factor kappa-light-chain enhancer of activated B cells (NF-κB) into the nucleus based on an increase in the degradation of NF-κB inhibitor alpha, in the presence of TGF-β1, as did H2O2 treatment. In conclusion, H. pylori infection along with an elevated TGF-β1 may accelerate hepatic fibrosis through increased TGF-β1-induced pro-inflammatory signaling pathways in HSCs. Moreover, H. pylori infection might increase the risk of TGF-β1-mediated tumorigenesis by disturbing the balance between apoptosis and proliferation of hepatocytes.

Helicobacter pylori and Hepatitis C Virus Coinfection in Egyptian Patients

INTRODUCTION

Chronic hepatitis C virus (HCV) infection is a leading cause of end-stage liver disease worldwide. It has been shown that Helicobacter pylori (H. pylori) plays an important role in chronic gastritis, peptic ulcer disease and gastric malignancies, and its eradication has been advocated. The association between H. pylori infection and liver cirrhosis in patients with hepatitis C virus has been documented in different parts of the world; nevertheless, no conclusive data is available in Egypt.

MATERIALS AND METHODS

In the present study, the status of H. pylori infection was sought in 90 patients with chronic HCV infection and in 66 HCV-free healthy controls.

RESULTS

The study showed that the H. pylori positivity was increased significantly (P = 0.03) in the HCV-infected patients when compared to that in healthy controls, where H. pylori infection was found in 50 (55.6%) out of 90 of the HCV-infected patients versus 26 (39.4%) out of 66 of the healthy controls. In HCV-infected patients, the prevalence of H. pylori infection was increased significantly (P = 0.04) from chronic active hepatitis to cirrhosis. H. pylori infection was present in 6/18 (33.3%), 10/21 (47.6%), 16/27 (59.3%), 18/24 (75.0%) patients with chronic active hepatitis, Child-Pugh score A, Child-Pugh score B and Child-Pugh score C, respectively. More importantly, the prevalence of H. pylori infection in HCV-infected patients was increased very significantly (P = 0.003) with increasing Meld (model for end-stage liver disease) score. The prevalence of H. pylori was documented in 9/28 (32.1%) patients with Meld score >10 and in 41/62 (66.1%) patients with Meld score >10.

CONCLUSION

It may be stated that our results collectively reflect a remarkable increase in H. pylori prevalence with advancing hepatic lesions, and the eradication treatment may prove beneficial in those patients with chronic hepatitis C.

Hepatocellular carcinoma: prevalence and molecular pathogenesis of Helicobacter spp

Helicobacter pylori infection is one of the most common chronic bacterial infections in humans. The association of other Helicobacter spp. with extragastric diseases in animals is well established, and a role of these bacteria in human liver disease is becoming clearer. Several case-control studies have reported possible associations of Helicobacter spp. with various liver diseases, including hepatocellular carcinoma, which is the fifth most common type of carcinoma among men worldwide, and the eighth most common among women. Thus, it is important to understand molecular mechanisms that may lead to hepatotoxicity or hepatocellular dysfunction in which Helicobacter spp. may play a role in inducing malignant transformation of liver cells.

Lipopolysaccharide promotes adhesion and invasion of hepatoma cell lines HepG2 and HepG2.2.15

Inflammation and infection have been linked to the bionomics of many cancers, including hepatocellular carcinoma (HCC). Some bacteria, such as Helicobacter pylori, have been found in pathological specimens from patients with HCC. However, little is known about the direct effects of bacteria or their components on hepatoma cells. We analyzed the in vitro proliferation, adhesion and invasion responses of the tumor cell lines HepG2 and HepG2.2.15 to lipopolysaccharide (LPS), a cell wall constituent of Gram-negative bacteria. HepG2 and HepG2.2.15 cells show increased proliferation in response to LPS. Their invasion and adhesion abilities were also increased in response to LPS, which may be related to increased gene expression of interleukin-8 and transforming growth factor-beta1. We infer that bacteria may be ignored by immune systems and directly promote adhesion and invasion of hepatoma cells through LPS.

Detection of Helicobacter pylori in paraffin-embedded specimens from patients with chronic liver diseases, using the amplification method

Helicobacter DNA has been detected in the liver specimens of patients with various hepato-biliary diseases. The aim of this study was to investigate the presence of H. pylori DNA in the liver tissue of Iranian patients with chronic liver diseases (CLD). Genomic DNA was extracted from the paraffin sections of 46 liver biopsies of patients with CLD and 13 from patients with metastatic adenocarcinoma as a control group. Polymerase chain reaction (PCR) analysis was carried out using primers for H. pylori 16S rRNA and cagA genes. On analysis, 17 of the 46 patient samples were positive in H. pylori 16S rRNA PCR and 2 of the 13 were positive from the control group. None of the samples were positive for the cagA gene. This study showed the greater presence of H. pylori-like DNA in the liver samples from patients with CLD than in controls.

DNA of Helicobacter spp. and common gut bacteria in primary liver carcinoma

BACKGROUND AND AIM

Gastric and enteric Helicobacter species have been associated with the pathogenesis of some extragastric diseases.

METHODS

We retrospectively investigated the presence of DNA of Helicobacter species in samples of the cancer and the surrounding tumour-free liver tissues of patients with hepatocellular carcinoma (HCC, n=12) and cholangiocarcinoma (CC, n=13). The patients were from an area with low liver cancer incidence and with low hepatitis B and C prevalence. Patients with a benign liver disease (n=24) were included as controls. Paraffin-embedded liver samples were examined by a Helicobacter genus-specific PCR assay as well as group-specific PCR assays for Enterobacteriaceae, Bacteroides, Lactobacillus and Enterococcus. PCR products of positive samples were characterised by denaturing gradient gel electrophoresis (DGGE) and DNA sequencing.

RESULTS

PCR assay detected Helicobacter DNA in seven of 12 (58%) and eight of 13 (62%) normal liver tissue specimens from HCC and CC patients, respectively. Two cancer samples from HCC patients were Helicobacter-positive but none of the CC cancers. In the control group, three of 24 (12.5%) patients with a benign liver condition were positive for Helicobacter species (p<0.01 compared to results of tumour-free liver tissue from the cancer patients). DGGE and DNA sequence analysis showed that 90% of the detected PCR products were "H. pylori-like". DNA of some other enteric bacteria was detected in the liver of one cancer patient and one control (4% of all patients).

CONCLUSION

The presence of DNA of Helicobacter species in liver specimens, but not of other common gut bacteria, was associated with human hepatic carcinogenesis.

Identification of Helicobacter species by 16S rDNA PCR and sequence analysis in human liver samples from patients with various etiologies of benign liver diseases

BACKGROUND/AIMS

Several reports indicated an increased prevalence of the Helicobacter species in hepatocellular cancer tissue and in liver samples infected with hepatitis viruses. The frequency of Helicobacter spp. in benign liver diseases was, however, not thoroughly investigated.

METHODS

Seventy-five consecutive patients with suspected liver disease were enrolled. The indications were hepatitis B virus (n=30), C virus (n=8), B and C dual infection (n=1), nonalcoholic steatohepatitis (n=27), autoimmune hepatitis (n=3), primary biliary cirrhosis (n=1) and idiopathic elevation of liver enzymes (n=5). PCR detection of 16S recombinant RNA gene of Helicobacter spp. was performed on liver samples. PCR products of positive samples were further identified by DNA sequencing. The patients also had upper gastrointestinal endoscopy and gastric biopsy for the detection of H. pylori using histopathology and PCR.

RESULTS

Helicobacter spp. DNA was detected in two out of 75 liver biopsy samples (2.6%), which were typed as H. pylori by DNA sequencing. One of these patients had chronic hepatitis C infection (man, 51 years old) and the other had nonalcoholic steatohepatitis (woman, 44 years old). Fifty-two out of 75 of the patients (69.3%) had H. pylori infection in their stomachs.

CONCLUSION

We have found that H. pylori infection is much less prevalent in benign liver diseases. The presence of H. pylori in nonalcoholic steatohepatitis (NASH) patients is a novel finding and this finding should be confirmed in a larger series.

Low frequency of Helicobacter DNA in benign and malignant liver tissues from Baltimore, United States

Helicobacter DNA has been reported in hepatocellular carcinoma tissues in several studies from varying geographic locations, raising the possibility that Helicobacter infection may contribute to the pathogenesis of hepatocellular carcinoma. Other known risk factors for hepatocellular carcinoma show significant geographic variability, but whether the same holds for Helicobacter is unknown. We studied the prevalence of Helicobacter DNA in a US cohort of hepatocellular carcinoma, where the prevalence of Helicobacter infection is low in the general population. Liver tissues from 57 individuals were examined. Thirty-five individuals had paired tumor/nontumor samples, including 21 cases of hepatocellular carcinoma, for a total of 92 samples studied. Both Helicobacter genus and Helicobacter pylori species-specific polymerase chain reaction was performed. Helicobacter DNA was detected in 5 (9%) of 57 cases, all in nonneoplastic cirrhotic liver tissues from individuals with hepatitis C infection (n = 4) or alcohol liver disease (n = 1). Tissues from 22 hepatocellular carcinomas and 10 cholangiocarcinomas were all negative as were tissues from 8 benign primary hepatic tumors. In conclusion, Helicobacter DNA was detectable in 9% of liver tissues in this cohort but was not found in primary benign or malignant liver tumors. These findings indicate that Helicobacter infection is unlikely to be etiologically associated with hepatocellular carcinoma in this cohort. If Helicobacter infection does contribute to the development of hepatocellular carcinoma in general, then significant regional variability must exist.

Bone marrow cells: the source of hepatocellular carcinoma?

Whether the stem cells or the mature cells are the origination of hepatocellular carcinoma is uncertain. Recently, researches have shown that some cancer stem cells could derive from adult stem cells. Moreover, gastric cancer could originate from bone marrow stem cells. Hematopoiesis and the hepatic environment are known to have a close relationship at the time of hepatic development and systemic diseases. Here we propose a new carcinogenetic model of hepatocellular carcinoma. Chronic liver injury could recruit bone marrow stem cells to the liver. Bone marrow cells take part in liver regeneration by differentiating to oval cells and hepatocytes. Persistent regeneration results in hyperproliferation, an increased rate of transforming mutations. Extracellular matrix remodeling triggers a cascade of events that inhibits the transactivation potential of liver-specific transcription factors, blocks the maturation of stem cells, and then results in hepatocellular carcinoma.

Helicobacter pylori and hepatocellular carcinoma: correlated or uncorrelated?

Helicobacter pylori can be detected in liver tissue resected from patients with hepatocellular carcinoma. Conflicting reports regarding the relationship between H. pylori and hepatocellular carcinoma mean it is uncertain whether H. pylori acts as a troublemaker, co-risk factor or innocent bystander to the development of hepatocellular carcinoma. Clinical studies in patients without known causes of hepatocellular carcinoma are important to discover whether H. pylori is involved in the carcinogenesis of hepatocellular carcinoma. High quality prospective studies in patients with hepatocellular carcinoma, hepatitis C virus infection and no cirrhosis are needed to determine whether H. pylori is a co-risk factor for hepatocellular carcinoma.

Detection of Helicobacter species in liver and stomach tissues of patients with chronic liver diseases using polymerase chain reaction-denaturing gradient gel electrophoresis and immunohistochemistry

OBJECTIVE

Helicobacter DNA has been detected in the hepatobiliary tree of patients with chronic liver diseases (CLD). The presence of H. pylori in the stomach compared with in the liver of the same patients with CLD has not been studied, therefore to the aim of this study was to investigate the presence of Helicobacter DNA and antigens in the liver and stomach of Polish patients with chronic liver diseases using molecular and immunological methods.

MATERIAL AND METHODS

Gastric mucosa and liver tissue samples and sera were collected from 97 Polish patients with CLD. Anti-H. pylori antibodies were detected by enzyme immunoassay (EIA), and H. pylori-like antigens detected by immunohistochemistry. Helicobacter DNA was detected in stomach and liver samples using a semi-nested Helicobacter genus-specific polymerase chain reaction (PCR) assay, and Helicobacter species identified by denaturing gradient gel electrophoresis (DGGE) and sequencing analysis of amplified PCR products.

RESULTS

H. pylori was identified by DGGE and sequence analysis in 60/62 (97%) and 25/25 (100%) of the gastric and liver Helicobacter genus-positive samples, respectively, whereas DNA of H. heilmannii was detected in 2/62 (3%) of the Helicobacter genus-positive gastric samples. H. pylori cagA gene was detected in 23/62 (36%) and 3/25 (12%) gastric and liver tissue samples, respectively. H. pylori-like antigens were detected in 61/97 (63%) gastric mucosa and in 40/97 (41%) liver tissue samples.

CONCLUSIONS

H. pylori-like organisms appeared to dominate the gastric mucosa and liver tissue of Polish patients with CLD. The prevalence of the cagA gene was higher in stomach compared with liver samples, which suggests a possible role of cagA negative H. pylori-like organisms in CLD. On the other hand, no significant correlation was found between the presence of H. pylori-like DNA and antigens in the liver and liver function tests.

Lack of association between seroprevalence of Helicobacter pylori infection and primary biliary cirrhosis

AIM: To determine the association between seroprevalence of Helicobacter pylori (H pylori) infection and primary biliary cirrhosis (PBC).

METHODS: In this case-control study, 149 consecutive patients (10 males, 139 females, mean age 58.2 ± 11 years, range 26-82 years) suffering from PBC and 619 consecutive healthy volunteer blood donors (523 males, 96 females, mean age 47 ± 5.3 years, range 18-65 years) attending the Hospital Blood Bank and residing in the same area were recruited. A commercial enzyme linked immunosorbent assay was used to detect anti-H pylori (IgG) antibodies in serum.

RESULTS: Antibodies to H pylori were present in 78 (52.3%) out of 149 PBC-patients and in 291 (47%) out of 619 volunteers (P = 0.24, OR 1.24, 95% CI: 0.85-1.80). In the subjects less than 60 years old, the prevalence of H pylori infection among PBC-patients (40/79) was slightly higher than in controls (50.6% vs 46.2%) P = 0.46, OR = 1.19, 95% CI: 0.72-1.95). In those over 60 years, the prevalence of H pylori infection was similar between PBC-patients and controls (54.2% vs 57.8%, P = 0.7, OR 0.86, 95% CI: 0.36-2.07).

CONCLUSION: There is no association between seroprevalence of H pylori infection and primary biliary cirrhosis.