Association of Helicobacter species with hepatitis C cirrhosis with or without hepatocellular carcinoma.

BACKGROUND AND AIMS: Recent studies have suggested that bacterial coinfection with Helicobacter species in patients already infected with hepatitis C virus (HCV) could be involved in the development of cirrhosis and hepatocellular carcinoma (HCC). A retrospective cross sectional study was performed in order to explore the association between Helicobacter species and HCV associated liver diseases. METHODS: The presence of Helicobacter species was tested by polymerase chain reaction on liver samples from four groups of patients. RESULTS: Helicobacter 16S rDNA was found in only 4.2% of liver samples from control patients (n=24) and in 3.5% of liver samples from patients with non-cirrhotic chronic hepatitis C (n=29) while it was found in 68.0% of liver samples from patients with HCV positive cirrhosis without HCC (n=25) as well as in 61.3% of cirrhotic liver samples from patients with HCV positive cirrhosis and HCC (n=31). In addition, when the HCC tumour tissue was tested (n=21), 90.5% of samples were positive. DNA from Helicobacter pylori- and Helicobacter pullorum-like organisms was found. CONCLUSIONS: There is an association between the presence of Helicobacter species DNA in the liver and hepatitis C cirrhosis, with or without HCC. Indeed, the presence of these bacteria could be the result of structural changes in the liver. Alternatively, Helicobacter species could be a co-risk factor in HCV chronic liver diseases. This result warrants prospective studies to determine the possible causal role of these bacteria in the progression of chronic hepatitis C.

Anti-CagA antibodies in Helicobacter pylori-positive patients and blood donors from Nigeria.

The prevalence of antibodies to CagA protein was evaluated in 174 Helicobacter pylori-positive. subjects: 110 patients submitted to upper gastrointestinal endoscopy and 64 male blood donors. The patients were from different regions of Nigeria: Jos, North, Benue,West and East and the blood donors were from Jos. Sera were assayed for anti-CagA antibodies using Helicobacter p120, CagA ELISA (Viva Diagnostika, Hürth, Germany). Anti-CagA antibodies were detected in 104 (94.5%) patients and in 61 (95.3%) blood donors (P=1.0). Patients from the Benue region presented a lower frequency of anti-CagA antibodies than patients from the other regions (P=0.0004). When the subjects were stratified by age, a significant increase in IgG concentration was observed among the men (P=0.03) but not among the women (P=0.57) or among the blood donors (P=0.83). In conclusion, similarly toAsian countries, CagA-positive H. pylori infection is highly frequent in Nigeria.

vacA genotypes in Helicobacter pylori strains isolated from children with and without duodenal ulcer in Brazil.

Data concerning the association between vacA genotypes and disease in children in both developed and developing countries are scarce, especially because of the small number of children with a duodenal ulcer studied. The vacA genotypes of Helicobacter pylori strains obtained from 65 children (24 with a duodenal ulcer and 41 without a duodenal ulcer; 33 girls; mean age, 10.2 years; age range, 1 to 17 years) were investigated as described by J. C. Atherton et al. (J. Clin. Microbiol. 37:2979-2982, 1999). Ten (15.4%) children were infected with more than one H. pylori strain. None of these patients were included in our analysis of the relationship between gastric disorders and specific vacA genotypes. The s1 allele was detected in all H. pylori strains isolated from patients with a duodenal ulcer and from 21 (58.3%) patients without a duodenal ulcer (P = 0.003). Strains with the s2 allele were found only in patients without ulcer (n = 15; 41.7%). Most s1 strains had the s1b allele (97.5%), a result similar to that reported for adults from the Iberian peninsula, which could reflect the Brazilian population origin. One untypeable s1 strain was isolated. The m1 allele was also more frequently found in strains obtained from duodenal ulcer patients (P = 0.028). The m2 allele was found in strains obtained from 20 (36. 4%) children, 3 (15.8%) with an ulcer and 17 (47.2%) without an ulcer. Only one m hybrid strain (m1 and m2 hybrid) was detected. It was demonstrated for the first time that the frequencies of colonization with strains with the s1 allele (14.3% in children up to 8 years of age and 85.7% in older patients; P = 0.012) and of strains with the m1 allele (11.1% in patients up to the age 8 years and 88.9% in older children; P = 0.013) increase with age.

The interrelationship between Helicobacter pylori vacuolating cytotoxin and gastric carcinoma.

OBJECTIVE: We aimed to determine whether cytotoxin-positive Helicobacter pylori strains are associated with gastric carcinoma. METHODS: We studied 130 patients: 57 H. pylori-positive patients with gastric carcinoma, 53 H. pylori-positive patients without gastric carcinoma, and 20 H. pylori-negative subjects. The ability of H. pylori strains to produce vacuolating cytotoxin was tested in INT-407 and HeLa cells. The presence of antibodies to cytotoxin was investigated in blood serum from all subjects by immunoblotting. Fragments of the gastric mucosa from patients without gastric carcinoma and H. pylori-negative subjects were obtained for histopathological study. RESULTS: Considering the results as a whole, 40 (70.2%) patients with and 22 (41.5%) without gastric carcinoma were colonized by cytotoxin-positive strains. Antibodies against cytotoxin were not observed in the serum from 17 (29.8%) gastric carcinoma patients and from 31 (58.5%) patients without gastric carcinoma. H. pylori strains isolated from these patients did not produce cytotoxin in vitro. In regard to cytotoxin positivity, a significant difference was observed between patients with and without gastric carcinoma (p=0.004; odds ratio [OR]: 3.3; 95% confidence interval [CI]: 1.4-7.9). Higher scores of mononuclear (p=0.0001) and polymorphonuclear (p=0.000003) cells were observed in the antral mucosa from H. pylori-positive patients without gastric carcinoma infected by cytotoxin-positive strains than in those harboring cytotoxin-negative strains. CONCLUSION: Cytotoxin-producing H. pylori strains were more frequently observed in patients with gastric carcinoma and this aspect emphasizes the role of cytotoxin in the genesis of the tumor.