Association between human leukocyte antigen gene polymorphisms and multiple EPIYA-C repeats in gastrointestinal disorders.

BACKGROUND: Polymorphisms of human leukocyte antigen (HLA) genes are suggested to increase the risk of gastric cancer (GC). AIM: To investigate the HLA allele frequencies of patients with GC relative to a control group in terms of CagA+ multiple (≥ 2) EPIYA-C repeats. METHODS: The patient group comprised 94 patients [44 GC and 50 duodenal ulcer (DU) patients], and the control group comprised 86 individuals [(50 non-ulcer dyspepsia patients and 36 people with asymptomatic Helicobacter pylori (H. pylori)]. Polymerase chain reaction was performed for the amplification of the H. pylori cagA gene and typing of EPIYA motifs. HLA sequence-specific oligonucleotide (SSO) typing was performed using Lifecodes SSO typing kits (HLA-A, HLA-B HLA-C, HLA-DRB1, and HLA-DQA1-B1 kits). RESULTS: The comparison of GC cases in terms of CagA+ multiple (≥ 2) EPIYA-C repeats showed that only the HLA-DQB1*06 allele [odds ratio (OR): 0.37, P = 0.036] was significantly lower, but significance was lost after correction (Pc = 0.1845). The HLA-DQA1*01 allele had a high ratio in GC cases with multiple EPIYA-C repeats, but this was not significant in the univariate analysis. We compared allele frequencies in the DU cases alone and in GC and DU cases together using the same criterion, and none of the HLA alleles were significantly associated with GC or DU. Also, none of the alleles were detected as independent risk factors after the multivariate analysis. On the other hand, in a multivariate logistic regression with no discriminative criterion, HLA-DQA1*01 (OR = 1.848), HLA-DQB1*06 (OR = 1.821) and HLA-A*02 (OR = 1.579) alleles were detected as independent risk factors for GC and DU. CONCLUSION: None of the HLA alleles were detected as independent risk factors in terms of CagA+ multiple EPIYA-C repeats. However, HLA-DQA1*01, HLA-DQB1*0601, and HLA-A*2 were independent risk factors with no criterion in the multivariate analysis. We suggest that the association of these alleles with gastric malignancies is not specifically related to cagA and multiple EPIYA C repeats.

The Prevalence of Periodontal Pathogenic Bacteria in Atherosclerotic Cardiovascular Disease.

BACKGROUND: A possible link between periodontal pathogenic bacteria and atherosclerosis may exist based on the inflammatory mechanisms initiated by bacteria found in periodontal lesions. Our aim was to investigate the presence of DNA originating from T. denticola, C. rectus, T. forsythia, and P. gingivalis in the vascular tissue specimens obtained from patients who underwent surgery for arteriosclerotic vascular disease in this study. METHODS: A total of 96 patients diagnosed with valvular heart disease due to atherosclerosis and 85 patients with advanced aortic valve stenosis due to rheumatic fever and had undergone aortic valve replacement were included as the study (PG) and the control groups (CG), respectively. Atheroma plaques and vascular tissue specimens were collected from PG and CG during cardiovascular surgical procedures. Revitalization of the lyophilized T. denticola, ATCC 35405; C. rectus, ATCC 33238; P. gingivalis, ATCC 33277 and T. forsythia, ATCC 43037 strains was performed according to the manufacturer's instructions. C. rectus, T. forsythia, and T. denticola DNA samples were analyzed using the one-step in-house PCR method. RESULTS: In one (1.04%) and three (3.13%) out of 96 atherosclerotic PG tissue specimens, P. gingivalis and T. for-sythia DNA were detected, respectively. No T. denticola or C. rectus DNA was found in the study specimens. Periodontal pathogenic bacteria were not observed in 85 CG tissue specimens. There was no statistically significant difference between PG and CG for the presence of P. gingivalis and T. forsythia DNA using Fischer's Exact test (p > 0.05). CONCLUSIONS: In conclusion, with the case-control studies on a small scale such as in our study, it is not possible to determine a causality relationship between periodontal pathogenic bacteria and formation of atherosclerosis. Periodontal pathogenic bacteria may not be the only factor that causes inflammatory diseases associated with atherosclerosis. Host response and inflammatory mechanisms may be affected by other factors such as ethnicity, dietary habits, nutritional availability, and lifestyle. Taken together, it is difficult to conclude a causal link between periodontal pathogenic bacteria and formation of atherosclerosis.

Diagnostic performance of the RT-qPCR method targeting 85B mRNA in the diagnosis of pulmonary Mycobacterium tuberculosis infection.

BACKGROUND: Several nucleic acid amplification techniques (IS6110, 16S rRNA, and 85B mRNA) were developed for the rapid, direct detection of Mycobacterium tuberculosis. We aimed to assess the diagnostic performance of 85B mRNA-based RT-qPCR by comparing with the real-time PCR COBAS TaqMan MTB Kit while using the BACTEC MGIT 960 method as the gold standard. METHODS: 60 patients with confirmed pulmonary TB and 60 individuals without TB were included as the study and control groups, respectively. Sputum specimens were cultured using LJ and BACTEC MGIT 960 systems. Extracted DNA was used for COBAS PCR in a CONAS TaqMan 48 analyzer. 85B mRNA detection was performed by RT-qPCR. RESULTS: The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of COBAS TaqMan MTB Test were detected as 93.3%, 83.3%, 84.8%, 92.6%, and 88.3%, respectively. The same diagnostic parameters of RT-qPCR were: 98.3%, 95.0%, 95.2%, 98.3%, and 96.7%, respectively. According to the binary logistic regression analysis, RT-qPCR (OR: 19,924, p<0.001) was identified as the more optimal test. CONCLUSION: RT-qPCR targeting the 85B gene of M. tuberculosis seems to be a more useful and rapid technique than DNA-based methods for detecting live M. tuberculosis bacilli from sputum specimens.