Analysis of serum antibody profile against H pylori VacA and CagA antigens in Turkish patients with duodenal ulcer

AIM: To investigate the frequency of seropositivity aga- inst CagA, VacA proteins and to determine their indepen- dent effects on the development of duodenal ulcer (DU) in Turkish patients. METHODS: The study was designed as a prospective one from a tertiary referral hospital. Dyspeptic patients who were referred to our endoscopy unit for upper gas- trointestinal endoscopy between June 2003 and March 2004 and diagnosed to have DU or nonulcer dyspepsia (NUD) were included. Biopsies from the antrum and body of the stomach were taken in order to assess the current H pylori status by histology, rapid urease test and culture. Fasting sera were obtained from all patients and H pylori status of all sera was determined by IgG antibo- dies using an enzyme-linked immunosorbent assay (ELI- SA) kit. All seropositive patients were further analysed using Western blot assays detecting IgG antibodies aga- inst CagA and VacA proteins. The χ2 test was used for statistical comparison of the values and age-sex adjusted multiple regression analysis was used to determine the independent effects of CagA and VacA seropositivities on the development of DU. RESULTS: Sixty-three patients with DU and 62 patients with NUD were eligible for the final analysis. Seropositi- vity for anti-CagA was detected in 51 of 62 (82%), andin 55 of 63 (87%) patients with NUD and DU, respec- tively (p = no significance), and seropositivity for anti- VacA was found in 25 of 62 (40% ) and in 16 of 63 (25%) patients, with NUD and DU, respectively. CONCLUSION: These findings suggest that none of the- se virulence factors is associated with the development of DU in the studied Turkish patients with dyspepsia.

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.