PCR in Helicobacter spp. diagnostic in extragastric malignancies of digestive system

The validity evaluation of different 16srRNA gene primers for helicobacter detection urgently requesting to design new specific primers

Molecular diagnosis of helicobacters by PCR is simpler, more accurate, and feasible compared to other diagnostic methods. Validity and accuracy are highly dependent on the PCR primer design, diffusion time, and mutation rate of helicobacters. This study aimed to design 16srRNA -specific primers for Helicobacter spp. and H. pylori. Application of comparative statistical analysis of the diagnostic utility of the most available 16srRNA genus-specific primers. The new primers were designed using bioinformatics tools (MAFFT MSA and Gblocks command line). A comparative study was applied on nine genus-specific 16srRNA primers in comparison to the ConsH using in silico and laboratory evaluation. The results demonstrated that the best specificity and sensitivity of the primers designed for this study compared to other primers. The comparative study revealed that the heminested outer/inner primers were the worst. Although H276, 16srRNA(a), HeliS/Heli-nest, and Hcom had acceptable diagnostic utility, false positive and false negative results were obtained. Specificity testing on clinical samples indicated a surprising result; that H. pylori was not the sole enemy that we were looking for, but the Non-Helicobacter pylori Helicobacters should be considered as a real risk prognostic for gastric diseases, consequently, a specific diagnosis and treatment should be developed. This study concluded that our designed primers were the most specific and sensitive in comparison with other primers. In addition, in silico evaluation is not accurate enough for primer assessment and that the laboratory evaluation is mandatory.

Helicobacter Species are Possible Risk Factors of Cholangiocarcinoma

Several infectious agents are considered to be causes of cancer in human, mainly hepatitis B and C viruses, high-risk human pailloma viruses, Helicobacter pylori, Clonorchis sinensis, and Opisthorchis viverrini. Here we described the evident research and the association between Helicobacter spp. and biliary tract cancer particularly cholangiocarcinoma (CCA). Global epidemiological studies have suggested that Helicobacter spp. are possible risk factors for biliary tract diseases. Molecular studies support a linkage of Helicobacter spp. with CCA development. H. pylori, H. bilis, and H. hepaticus, are found in CCA, but the most common species are H. pylori and H. bilis. The type of CCA are associated with Helicobacter spp. include extrahepatic CCA, and common bile duct cancer. Up to the present, however, the results from different regions, materials and methods, sub-sites of cancer, and controls have not been consistent, thus introducing heterogeneity. Therefore, a comparison between co-Helicobacter spp.-CCA in the countries with low and high incident of CCA is required to settle the question. Furthermore, clarifying variation in the role of Helicobacter species in this CCA, including pathogenesis of CCA through enhanced biliary cell inflammation and proliferation, is necessary.

Diagnosis of Genus Helicobacter through a hemi-nested PCR assay of 16S rRNA

The present study aimed to establish a genus-specific PCR-based assay to detect helicobacters using 16S rRNA gene as the target template. We designed the hemi-nested primers based on sequences of 16S rRNA gene of 34 types of Helicobacter species. The inclusivity, sensitivity, and specificity of the PCR assay using these primers were examined in three different models, comprising feces simulated samples, BLAB/c mice infection model and clinic patients samples. The detection sensitivity of Helicobacter pylori, Helicobacter hepaticus and Helicobacter bilis strains from feces simulated samples was all 102 CFU/ml. We successfully detected H. hepaticus and H. bilis in the liver, cecum and feces of experimentally infected mice. H. pylori was successfully detected in the feces samples from 3 patients infected with H. pylori while not in the feces samples from 3 healthy human. However, the C97/C05–C97/C98 PCR assay detected H. pylori in the 2 positive samples. Due to the PCR assay’s excellent inclusivity, high sensitivity and specificity it may be used to detect the presence of Helicobacters.

The effect of Helicobacter pylori eradication on liver enzymes in patients referring with unexplained hypertransaminasemia

BACKGROUND

Evidence has shown an association of Helicobacter pylori infection with liver dysfunction and damage. We investigated if H. pylori eradication affects liver enzymes in patients referring with unexplained hypertransaminasemia.

MATERIALS AND METHODS

Patients with mild unexplained hypertransaminasemia accompanied with dyspepsia and confirmed H. pylori infection were studied. Viral, metabolic, autoimmune, and drug/toxin induced hepatitis as well as fatty liver were all ruled-out by appropriate tests. Patients received bismuth-containing quadruple-therapy for 2 weeks. Serum levels of liver enzymes (alanine transaminase (ALT) and aspartate transaminase (AST)) and successful eradication (with stool antigen test) were evaluated 4 weeks after the medication.

RESULTS

A total number of 107 patients (55 males, mean age = 35.0 ± 8.4 years) were studied. Eradication was successful in 93 patients (86.9%). Serum levels of AST (6.3 ± 19.6 IU/L, P = 0.002) and ALT (7.8 ± 24.9 IU/L, P = 0.001) were significantly decreased after eradication. Levels of AST and ALT decreased to normal range respectively in 46.6% and 45.7% of the cases who had baseline levels above the normal range.

CONCLUSION

This study showed a decrease in liver enzymes after receiving eradication regimen of H. pylori, suggesting a role for H. pylori infection in at least some of patients with mild unexplained hypertransaminasemia. Further studies are warranted to find the underlying mechanisms by which H. pylori infection affects the liver and clinical importance of such effects.

Extragastric manifestations of Helicobacter pylori infection

In the last year, different diseases possibly linked to Helicobacter pylori infection but localized outside of the stomach have been investigated. There are, in fact, several studies concerning cardiovascular diseases, hematologic disorders, neurologic diseases, metabolic, hepatobiliary diseases, and other conditions. Some of those studies, such as those on sideropenic anemia and idiopathic thrombocytopenic purpura, are quite large and well conducted, while in other cases there are just small or isolated studies or even case reports. Nonetheless, there is much interest among researchers all over the world for such a topic as demonstrated by the large number of studies published in the last year.