Serum antibodies positivity to 12 Helicobacter pylori virulence antigens in patients with benign or malignant gastroduodenal diseases--cross-sectional study

Simultaneous and alternative IgG seroreactivity against Helicobacter pylori antigens VacA ,30 kDa and 50 kDa is a better biomarker approach for the outcome of infection than VacA and 50 kDa alone

Background/Aim. In our previous study, IgG seropositivities against Helicobacter (H) pylori antigens VacA, 50 kDa, 30 kDa, and 26 kDa were highlighted as biomarkers for the specific outcome of infection. We designed and conducted this study in order to investigate whether synchronous and/or alternative seroreactivity against H. pylori antigens VacA, 50 kDa, 30 kDa and 26 kDa in patients with gastric cancer and peptic ulcers exhibit stronger association than with dyspepsia and vice versa. Methods. In order to determine IgG antibodies to H. pylori antigens, a Western blot test was performed in 123 patients: 31 with gastric cancer, 31 with duodenal ulcer, 31 with gastric ulcer and 30 with functional dyspepsia. We analyzed IgG sero-reactivity against four H. pylori antigens (VacA, 50 kDa, 30 kDa, 26 kDa) in their synchronous/alternative combination as well as seroreactivity to synchronous and alternative combinations of H. pylori antigens between a group with functional dyspepsia and others. The analysis of diagnostic characteristics of the best synchronous and alternative seroreactivity combination was done, and tested versus VacA a s biomarker for gastric cancer and peptic ulcer, and 50 kDa as a biomarker for dyspepsia. Results. VacA seropositivity or 50 kDa seronegativity (p = 0.015) and VacA seropositivity or 50 kDa and 30 kDa seronegativity (p =0.044) had the better diagnostic characteristics with statistically significantly better fraction correct than VacA seropositivity alone. VacA seronegativity along with50 kDa and 30 kDa seropositivity (p = 0.003), 50 kDa seropositivity (p = 0.01), 30 kDa seropositivity (p = 0.015) and 50 kDa or 30 kDa seropositivity (p = 0.02) had better diagnostic characteristics and significantly better fraction correct than 50 kDa seropositivity alone. Conclusion. Simultaneous and alternative IgG seroreactivity/unreactivity against H. pylori antigens VacA, 50 kDa and 30 kDa have stronger association with the specific infection outcome, considering gastric cancer and peptic ulcer, or dyspepsia, than VacA and 50 kDa IgG seropositivity alone.

Seroreactivity against Helicobacter pylori VacA,50kDa and 30kDa along with alarm features may improve the diagnostic approach to uninvestigated dyspepsia: A pilot study

Background/Aim. Alarm features (AF) are of limited utility in predicting endoscopic findings, and the majority of patients with uninvestigated dyspepsia will have no organic pathology identified at upper gastrointestinal endoscopy. In our previous study, we highlighted seroreactivity against Helicobacter pylori (HP) antigens VacA, 50 kDa, and 30 kDa as biomarkers for gastric cancer, peptic ulcers, and functional dyspepsia. We designed and conducted this pi-lot study in order to compare the diagnostic utility of seroreactivity against HP VacA, 50 kDa, and 30 kDa with AF and investigate the possibility and adequacy of its synchronous application. Method. A careful history and physical examination with special attention to AF, esophagogastroduodenoscopy with biopsy, abdominal ultra-sound or computer tomography, complete blood count (CBC) and blood biochemistry, a Western Blot IgG against HP antigens VacA, 50 kDa, and 30 kDa, were per-formed in 123 patients with dyspepsia: 31 with gastric cancer, 31 with duodenal ulcer, 31 with gastric ulcer, and 30 with gastritis and functional dyspepsia. AF vs various combinations of seroreactivity against HP VacA, 50 kDa, and 30 kDa in patients with functional dyspepsia and others were analyzed in this study. Synchronous and alternative seroreactivity against VacA, 50 kDa, and 30 kDa, along with/without AF in patients with functional dyspepsia and other groups of patients were also analyzed. Results. VacA and 50 kDa seropositivity or AF had excellent case-findings clinical utility index for investigating dyspepsia. The absence of AF and seroreactivity against VacA either with: 50 kDa or 30 kDa seropositivity or 50 kDa and 30 kDa seropositivity had an excellent screening clinical utility index for investigating dyspepsia. Conclusion. Se-roreactivity against HP antigens VacA, 50 kDa, and 30 kDa might improve our approach to patients in investigating dyspepsia if used along with AF.

Antigen-specific humoral responses against Helicobacter pylori in patients with systemic sclerosis

Helicobacter pylori (Hp) is a likely trigger of systemic sclerosis (SSc), but systemic antigen-specific antibody (Ab) responses in a well-defined cohort of SSc patients have not been thoroughly assessed. Line immunoassay and immunoblotting testing Abs against 15 Hp antigens were performed in 91 SSc patients and 59 demographically matched healthy controls (HCs). Results were validated in an independent cohort of 35 SSc patients. Anti-Hp positivity was detected in 67% SSc patients vs 76.3% HCs. Among anti-Hp (+) individuals, anti-p67-FSH was less frequent in SSc than HCs (p = 0.016), whereas reactivity to the remaining 14 Hp antigens did not differ between patients and HCs. Anti-p67 Abs were less frequent in diffuse cutaneous SSc (dcSSc) compared with HCs (p = 0.018). Anti-p57 and anti-p33 Ab levels were lower in SSc vs HCs (p = 0.007 and p = 0.035, respectively). Anti-p57 and anti-p33 Ab levels were lower in limited cutaneous SSc (lcSSc) (p = 0.010) and dcSSc (p = 0.024), respectively, compared with HCs. Anti-p50 and anti-p17 Ab titers tended to be higher in dcSSc than in lcSSc. Sera from the independent SSc cohort showed comparable results. Anti-VacA Abs were more frequent in pulmonary arterial hypertension (p = 0.042), and anti-p30 Abs were more frequent in calcinosis (p = 0.007), whereas anti-VacA Ab levels were higher in lung fibrosis (p = 0.02). In conclusion, anti-Hp Abs are neither more frequent nor elevated in SSc compared with healthy population, the only exception being the higher frequency and levels of anti-VacA Abs in pulmonary hypertension and lung fibrosis, respectively. These results suggest that Hp is unlikely to be involved in the development of SSc.

Vacuoles of Candida yeast as a specialized niche for Helicobacter pylori

Helicobacter pylori (H. pylori) are resistant to hostile gastric environments and antibiotic therapy, reflecting the possibility that they are protected by an ecological niche, such as inside the vacuoles of human epithelial and immune cells. Candida yeast may also provide such an alternative niche, as fluorescently labeled H. pylori were observed as fast-moving and viable bacterium-like bodies inside the vacuoles of gastric, oral, vaginal and foodborne Candida yeasts. In addition, H. pylori-specific genes and proteins were detected in samples extracted from these yeasts. The H. pylori present within these yeasts produce peroxiredoxin and thiol peroxidase, providing the ability to detoxify oxygen metabolites formed in immune cells. Furthermore, these bacteria produce urease and VacA, two virulence determinants of H. pylori that influence phago-lysosome fusion and bacterial survival in macrophages. Microscopic observations of H. pylori cells in new generations of yeasts along with amplification of H. pylori-specific genes from consecutive generations indicate that new yeasts can inherit the intracellular H. pylori as part of their vacuolar content. Accordingly, it is proposed that yeast vacuoles serve as a sophisticated niche that protects H. pylori against the environmental stresses and provides essential nutrients, including ergosterol, for its growth and multiplication. This intracellular establishment inside the yeast vacuole likely occurred long ago, leading to the adaptation of H. pylori to persist in phagocytic cells. The presence of these bacteria within yeasts, including foodborne yeasts, along with the vertical transmission of yeasts from mother to neonate, provide explanations for the persistence and propagation of H. pylori in the human population. This Topic Highlight reviews and discusses recent evidence regarding the evolutionary adaptation of H. pylori to thrive in host cell vacuoles.