HLA-DQA1 and -DQB1 genes and Helicobacter pylori infection in Italian patients with gastric adenocarcinoma

HLA class II polymorphisms as prognostic biomarkers for right and left-sided colon cancer

BACKGROUND

Colon cancer (CC) is one of the most common malignancies worldwide. Characterization of new prognostic biomarkers for right-sided CC (RCC) and left-sided CC (LCC) may contribute to improving early detection. An association of human leukocyte antigens class II (HLA-II) with the predisposition to CC was suggested.

AIM OF THE STUDY

We evaluated the association of DRB1 and DQB1 with the risk of LCC and RCC.

PATIENTS AND METHODS

Our study comprised 93 CC patients and 100 healthy controls. Genotyping of HLA class II alleles were performed by the Polymerase Chain Reaction Sequence-Specific Primers (PCR-SSP).

RESULTS

DRB1*03 was positively associated with CC. In contrast, DRB1*11, DRB1*13, DQB1*03, and DQB1*05 were negatively linked to CC. Haplotype analysis revealed that DRB1*04-DQB1*04 and DRB1*09-DQB1*02 were positive, while DRB1*01-DQB1*05, DRB1*04-DQB1*03, DRB1*07-DQB1*02, DRB1*11-DQB1*03, DRB1*11-DQB1*05, and DRB1*13-DQB1*06 were negatively associated with CC. For sigmoid CC, DRB1*13, DRB1*11, and DQB1*05 were negative, while DRB1*04-DQB1*02, and DRB1*07-DQB1*03 were positively associated. DRB1*03 and DRB1*04-DQB1*04 were positive, while DRB1*11 and DQB1*03 were negatively linked to RCC. According to the LCC, DRB1*07, DRB1*11, DQB1*03, DQB1*05, and DRB1*07-DQB1*02 were negative. In contrast, DRB1*09-DQB1*02 was positively associated with LCC. Stratified analysis revealed that DRB1*11 is associated with higher risk of metastasis in CC and sigmoid CC, and tolerance to treatment in RCC. DQB1*03 was associated with lymph-node invasion in CC.

CONCLUSION

DRB1 and DQB1 polymorphisms could be used as future biomarkers for the early detection of subjects at a higher risk of developing RCC and LCC, metastasis in sigmoid CC, and tolerance to treatment in RCC.

HLA-DQB1*03 genotype and perioperative blood transfusion are not conducive to the prognosis of patients with gastric cancer

BACKGROUND

Gastric cancer (GC) is a disease associated with a higher incidence and mortality, and some host genetic polymorphisms have been reported as potential factors contributing to the development of GC. In view of this, the study was conducted to investigate the effects of HLA-DQB1 gene polymorphisms and perioperative blood transfusion on prognosis of patients with gastric cancer (GC).

METHODS

A total of 142 patients with GC (case group) and 150 healthy controls (control group) were enrolled. Relationship between HLA-DQB1 gene polymorphisms, perioperative blood transfusion, and clinical pathological parameters of patients with GC after operation was analyzed. Kaplan-Meier curve was applied for analyzing survival rate of patients with GC, and Cox multivariate regression analysis for prognostic factors of patients with GC.

RESULTS

The frequency of HLA-DQB1*03 gene was increased in patients with GC. Patients with GC with HLA-DQB1*03 genotype had higher number of tumor size >6 cm, deeper depth of infiltration, higher LNM rate, and later stage of disease. Patients with HLA-DQB1*03 genotype had lower survival rate compared with other genotypes. Anemia before operation, depth of infiltration in T3 stage and T4 stage, LNM in N1 stage and N2 stage, and HLA-DQB1*03 genotype were regarded as independent risk factors for patients with GC.

CONCLUSION

These results demonstrate that HLA-DQB1*03 genotype and perioperative blood transfusion are not conducive to the prognosis of patients with GC, which could provide a reference for the treatment of GC.

Polymorphisms in HLA-DQ genes, together with age, sex, and Helicobacter pylori infection, as potential biomarkers for the early diagnosis of gastric cancer

BACKGROUND

Polymorphisms in inflammation-related genes are factors associated with the development of gastroduodenal diseases in Helicobacter pylori-infected individuals.

MATERIALS AND METHODS

We aimed to analyze polymorphisms in HLA-DQ, together with other host and H. pylori variables as risk factors for precancerous and cancerous gastric lesions. 1052 individuals were studied, including nonatrophic gastritis (NAG), intestinal metaplasia (IM), gastric cancer (GC) or duodenal ulcer (DU) patients, and healthy volunteers.

RESULTS

Patients with alleles DQA*01:01 (OR 0.78), *01:02 (OR 0.29), *01:03 (OR 0.31), and DQB*02:01/02 (OR 0.40) showed a reduced risk for GC. A multivariate logistic regression analyses showed that patients with homozygote genotypes DQA1*03:01 (OR 7.27) and DQA1*04:01 (OR 8.99) and DQB1*05:01:01 (OR 12.04) were at significantly increased risk for GC. Multivariate analyses also demonstrated that age (OR>10.0) and gender (OR>2.0) were variables that influenced significantly the risk for GC, while H. pylori infection (OR>2.5) increased the risk for IM.

CONCLUSIONS

We identified HLA-DQ alleles associated with IM and GC, and confirm that age, sex, and H. pylori infection are variables that also influence the risk for disease. The use of multiple markers, HLA-DQ alleles, age, sex, and H. pylori infection may be useful biomarkers for the early diagnosis of patients with IM and GC.

Distribution of HLA Tissue Groups in Patients with Gastric Cancer

OBJECTIVE

Gastric cancer is an important disease that is seen all over the world and that threats public health. At the same time, gastric cancer is a heterogeneous disorder with multifactorial etiologies. Recent studies have shown a significant association between HLA antigens and gastric adenocarcinoma. The aim of the present study was to determine the distribution of HLA class I (HLA-A, B and C) and class II (HLA-DR, DQ and DP) antigens in Turkish patients with gastric adenocarcinoma.

MATERIALS AND METHODS

HLA alleles or HLA haplotypes associated with gastric cancer were established in the Turkish population using PSR-SSP analysis in 71 unrelated patients with gastric cancer and in 82 unrelated healthy controls. The statistical significance of differences in allele frequencies between patients and controls was measured by the Chi-square test with Yates's correction.

RESULTS

The study revealed that the HLA-Cw5 antigen is more prevalent in patients with gastric cancer (p=0.042) and that the HLA-DRB1*15 antigen is more prevelent in the control group (p=0.021).

CONCLUSION

It is probable that HLA-Cw5 is a risk factor for gastric cancer whereas HLA-DRB1*15 plays a protective role for this disease. The results show that different loci on HLA may control resistance to or tendency for any disease in different societies; each society should determine its own tissue group.

Helicobacter pylori and gastric adenocarcinoma

Gastric cancer is the second most common cause of cancer death worldwide. A large body of evidence supports a causal role of Helicobacter pylori in the majority of gastric malignancies. Great strides have been made in understanding the pathogenesis of this relationship, but much remains to be learned. Moreover, because of the high prevalence of infection, the lack of definitive trials, and the challenges of H. pylori treatment, there remains no consensus on the role of routine screening and treatment of this infection to prevent cancer. This article reviews the current knowledge on H. pylori and gastric cancer and presents some of the clinical and public health challenges associated with this pathogen.

Synergistic effect of HLA class II loci and cytokine gene polymorphisms on the risk of gastric cancer in Japanese patients with Helicobacter pylori infection

It has been reported that polymorphisms of human leukocyte antigen (HLA) genes and several cytokine genes are associated with an increased risk of developing gastric cancer (GC). However, the results of studies from different geographic regions, ethnic groups and study groups are inconsistent. The aim of this study was to evaluate the influence of H. pylori infection and host genetic factors on GC susceptibility in Japanese patients with GC. We analyzed genotypes for HLA class I and II, tumor necrosis factor alpha, interleukin (IL)-1beta, IL-1 receptor, IL-4, IL-4Ralpha and IL-10 in 330 H. pylori-infected noncardia patients with GC and 190 H. pylori-infected nonulcer dyspeptic controls. Haplotype analyses indicated that the frequencies of the HLA DRB1*0405 and DQB1*0401 alleles were increased in the patients with intestinal-type GC when compared with controls (both DRB1*0405 and DQB1*0401: p = 0.015, OR = 1.57, 95% CI = 1.09-2.26), but the changes were not statistically significant after correction for multiple comparisons. None of the cytokine gene polymorphisms were associated with GC susceptibility, whether patients with GC were analyzed as a group according to the histological subtype. Of interest was the comparison of controls and patients with intestinal-type GC. The frequency of an IL-10-592AA homozygote showing concomitant carriage of the HLA DRB1*0405-DQB1*0401 haplotype was significantly higher in patients with intestinal-type GC (chi(2) = 6.369, p = 0.0116, p(c) = 0.0464, OR = 2.43, 95% CI = 1.21-4.48). Our results suggest that the HLA class II and IL-10-592A/C polymorphisms synergistically affect the susceptibility to GC development of H. pylori-infected individuals in the Japanese population.

Association of the human leukocyte antigen class II alleles with chronic atrophic gastritis and gastric carcinoma in Koreans

OBJECTIVE

Gastric carcinogenesis is a multi-step process and is influenced by several etiological agents, including the host's genetic factors. Since whether a patient remains with chronic superficial gastritis (CSG) or progresses to either chronic atrophic gastritis (CAG) or gastric carcinoma (GC) could be a genetic predisposition unique in each population, we hypothesized that host human leukocyte antigen (HLA) alleles could be discriminative in predicting the risk of CSG progression to precancerous CAG and GC in Koreans.

METHODS

A total of 165 patients with gastric disorders (CSG, 62; CAG, 69 and GC, 34), were selected to investigate the association of HLA class II alleles with the progression of CSG to CAG or GC. HLA genotypes were obtained by the polymerase chain reaction-sequence based typing method.

RESULTS

The phenotypic frequencies of DRB1*1101 and DQA1*0505 were significantly higher in the CAG group compared to those in the CSG group. In the subjects with Helicobacter pylori (H. pypori) (+), the frequencies of DRB1*1501 and DQB1*0602 were significantly lower in the CAG compared to those in the CSG. Further analysis showed that sex (P < 0.05, OR = 0.41-0.42) and age (P < 0.05, OR = 1.05) also affected the risk of progression from CSG to CAG in H. pylori (+) patients carrying the DRB1*1501 or DQB1*0602 allele. Additionally, the frequency of DRB1*0404 in the GC group was significantly higher than that in the gastritis group.

CONCLUSION

Our findings strongly imply an association between HLA class II alleles and the risk of CAG development and GC progression in Koreans.

Helicobacter Pylori associated global gastric cancer burden

Helicobacter pylori infection is ubiquitous, infecting close to one-half of the world's population, but its prevalence is declining in developed countries. Chronic H. pylori infection is etiologically linked to gastric adenocarcinoma, especially non-cardia type (63% of all stomach cancer or ~5.5% of the global cancer burden: ~25% of cancers associated with infectious etiology), and to gastric mucosal associated lymphoid tissue (MALT) lymphoma, which accounts for up to 8% of all non-Hodgkin lymphoma. Epidemiological, clinical, and animal studies have established a central role for H. pylori in gastric carcinogenesis and provided insights into the mechanisms and biologic relationships between bacterial infection, host genetics, nutrition, and environmental factors. These discoveries invite strategies to prevent infection to be the logical primary goals in a multi-pronged effort to curtail suffering and death from H. pylori infection-associated cancers.

Seroprevalence of Helicobacter pylori in Central-European uraemic patients and its possible association with presence of HLA-DR12 allele

OBJECTIVES

Renal disease at any stage is often accompanied by significant gastrointestinal symptoms, and Helicobacter pylori (H. pylori) is closely related to these disorders. A debate is still ongoing on the clinical significance of coexisting uraemia and H. pylori. HLA-class II genes have been repeatedly investigated for predisposition to H. pylori infection. The aim of our work was to evaluate the infection rate among uraemic patients, and study the relationship between HLA antigens and H. pylori serologic status in the same cohort.

MATERIALS AND METHODS

Data of 709 uraemic patients were collected and analyzed from 2001-2006. 58.7% of patients were male, 41.3% were female, mean age was 45.1 years (SD: +/-14.65). Microlymphocytotoxicity assay was used for typing of HLA class I, PCR-SSP for typing HLA class II alleles and enzyme immunofluorescency for specific H. pylori IgG.

RESULTS

Of 709 patients, 49.37% were seropositive for H. pylori. Age of H. pylori positive patients was 48.9 versus 41 years of negatives (P<0.0001). Prevalence of H. pylori decreased strongly with year of birth. Significant difference was observed in the occurrence of HLA-DR12 according to H. pylori serology. Of patients carrying DR12, 27 (73%) were H. pylori positive and 10 (27%) were negative [P=0.0037; risk ratios (RR): 2.76].

CONCLUSION

H. pylori infection rate and its decrease with year of birth was the same in the uraemic patients and in the normal population, according to specific prevalence figures. Frequency of HLA-DR12 was the same as in the general population; consequently, it might be a possible risk factor for H. pylori seropositivity, at least in a Central-European population.

Balancing selection and heterogeneity across the classical human leukocyte antigen loci: a meta-analytic review of 497 population studies

This paper presents a meta-analysis of high-resolution human leukocyte antigen (HLA) allele frequency data describing 497 population samples. Most of the datasets were compiled from studies published in eight journals from 1990 to 2007; additional datasets came from the International Histocompatibility Workshops and from the AlleleFrequencies.net database. In all, these data represent approximately 66,800 individuals from throughout the world, providing an opportunity to observe trends that may not have been evident at the time the data were originally analyzed, especially with regard to the relative importance of balancing selection among the HLA loci. Population genetic measures of allele frequency distributions were summarized across populations by locus and geographic region. A role for balancing selection maintaining much of HLA variation was confirmed. Further, the breadth of this meta-analysis allowed the ranking of the HLA loci, with DQA1 and HLA-C showing the strongest balancing selection and DPB1 being compatible with neutrality. Comparisons of the allelic spectra reported by studies since 1990 indicate that most of the HLA alleles identified since 2000 are very-low-frequency alleles. The literature-based allele-count data, as well as maps summarizing the geographic distributions for each allele, are available online.

Advance in research of genes associated with peptic ulcer

At present, studies about peptic ulcer have developed from cellular level to molecular level. More and more genes associated with peptic ulcer have been discovered, including human leukocyte antigen (HLA) genes, epidermal growth factor (EGF) genes, apoptosis-associated genes, calcitonin genes and trefoil peptide genes. These genes play important roles in the development and healing of peptic ulcer, providing theoretical basis for clinical diagnosis and cure of peptic ulcer.

Association between HLA-DQA1 alleles and H. pyloriinfection in Bai-ethnic children from Kunming

AIM: To find the susceptible or resistant genes of H. pyloriinfection in Bai-ethnic children of Kunming, and to explore the immunogenetic mechanism of H. pyloriinfection.

METHODS: Polymerase chain reaction-sequence specific primers (PCR-SSP) technique was used to detect the allelic distribution of HLA-DQA1 in Bai-ethnic children with or without H. pyloriinfection (n = 32, 34, respectively) from Kunming. H. pyloriinfection was identified by combination of dot-immunogold filtration assay and immunobloting technique.

RESULTS: The allelic frequency of HLA-DQA1 *010401 or *0402 was significantly lower in children with H. pyloriinfection than that in children without H. pyloriinfection (0 vs 15%, χ² = 0, P = 0.001, P = 0.014, OR = 1.172, 95%CI: 1.062-1.294).

CONCLUSION: HLA-DQA1^*010401 or ^*0402 may be resistant gene of H. pyloriinfection in Bai-ethnic children from Kunming.

HLA polymorphisms are associated with Helicobacter pylori infected gastric cancer in a high risk population, China

Helicobacter pylori is one of the most common bacterial infections associated with an increased risk of gastric cancer, but its association with host factors, particularly polymorphisms of the immune response genes, such as human leukocyte antigen (HLA) genes, is still unclear. To investigate the role of HLA polymorphisms in the risk of gastric cancer among subjects with H. pylori infection, a case-control study involving 52 gastric cancer patients and 139 non-cancer controls was conducted in Linqu County, China, an area with a high incidence of gastric cancer. Polymorphisms of HLA class I and class II alleles were determined by PCR with sequence-specific primers (PCR-SSP). The information about H. pylori infection was obtained from previous records. Among 48 class I and 19 class II HLA alleles detected in this study, two alleles, CW*03 and DRB1*01, were found to be distributed significantly differently between patients and controls [odds ratio(OR)=1.95, 95% confidence interval (CI)=1.13-3.35, P=0.017 and OR=4.39, 95% CI=1.39-13.84, P=0.012, respectively). The OR of gastric cancer risk in individuals carrying CW*03/CW*03 or CW*03/CW*N was 2.06, 95% CI=1.05-4.02, P=0.035, while the OR was 3.49, 95% CI=1.0-12.4, P=0.04 for DRB1*01/DRB1*01 or DRB1*01/DRB1*N carriers. The analysis of the interaction between H. pylori infection and HLA risk genotypes of CW*03 or DRB1*01 revealed that the effect of CW*03 and DRB1*01 genotypes on gastric cancer risk was manifested stronger in H. pylori-positive individuals (OR=5.30, 95% CI=1.73-16.29, P=0.004 and OR=13.38, 95% CI=2.52-70.98, P=0.002, respectively) than in H. pylori-negative ones (OR=1.25, 95% CI=0.25-6.12, P=0.785 and OR=2.26, 95% CI=0.18-28.88, P=0.531, respectively). The combined effect of the two risk HLA genotypes on gastric cancer risk was also analysed. The result showed that the individuals carrying both the CW*03 and DRB1*01 alleles could only be found in cancer patients (5/52), and not in controls (0/139), further suggesting that CW*03 and DRB1*01 are risk alleles advancing the progression of tumorigenesis. These observations demonstrate that host HLA genotypes may play an important role in the risk of gastric cancer, especially among persons with H. pylori infection.

Differential Effects of Helicobacter pylori Eradication on Oxidative DNA Damage at the Gastroesophageal Junction and at the Gastric Antrum

Background and Aim: Helicobacter pylori–associated gastritis causes accumulation of reactive oxygen species in the mucosal compartment. This prospective study evaluates DNA oxidative damage in biopsy samples obtained from both the antrum and the gastroesophageal junction (GEJ) before and after H. pylori eradication.

Patients and Methods: Thirty-two consecutive H. pylori–positive patients underwent endoscopy with multiple biopsy sampling (i.e., antrum, incisura angularis, fundus, and cardia at the GEJ). After H. pylori eradication, 32 patients underwent a checkup endoscopy (mean interval, 5.7 months); in a subgroup of 13 subjects, a third endoscopy procedure was also performed (mean interval, 18 months). Additional biopsy samples (two from the antrum and two from the GEJ) were used to assess 8-hydroxydeoxyguanosine (8OHdG) levels using both high-pressure liquid chromatography with electrochemical detector and ELISA.

Results: In the antral compartment, no significant modifications of 8OHdG levels were assessed after H. pylori eradication. Conversely, following eradication, 8OHdG levels significantly increased (high-pressure liquid chromatography with electrochemical detector, P = 0.04; ELISA method, P = 0.05) in biopsy samples taken from the GEJ, and a further increase was documented in the subgroup of patients who underwent a third endoscopy (P = 0.01). The increasing trend was more relevant in patients in whom H. pylori-cagA–positive strains were eradicated and in those affected by hiatal hernia.

Conclusions: The levels of DNA adducts in the antral mucosa are not modified by H. pylori eradication; conversely, H. pylori eradication significantly increases the oxidative adducts at the GEJ. The clinical and biological importance of this situation and whether and how it relates to a higher risk of precancerous lesions is open to debate.

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