Presence of gastric autoantibodies impairs gastric secretory function in patients with Helicobacter pylori-positive duodenal ulcer

The Relation of Cytotoxin-Associated Gene-A Seropositivity with Vitamin B12 Deficiency in Helicobacter pylori-Positive Patients

Background and Aim

As a worldwide infectious bacterium, H. pylori leads to stomach pathologies such as gastritis, peptic ulcer, gastric cancer, MALToma, and various extragastric manifestations. In our study, we aimed to investigate the association between serum vitamin B12 level and cytotoxin-associated gene-A (CagA) seropositivity, which is one of the virulence factors of Helicobacter pylori (H. pylori).

Method

This study has been conducted on 289 patients who have met the inclusion criteria. Within these patients, 213 of them were H. pylori positive and 76 were negative. Vitamin B12 and CagA-IgG levels were assessed in consecutive dyspeptic patients undergoing upper endoscopy.

Results

Out of 289 patients, 51.9% were women (n = 150) and H. pylori was detected in 213 (73.7%) patients. Histopathological evaluation with modified Sydney classification revealed lymphocyte infiltration in 66.8% (n = 193), activation in 46% (n = 133), metaplasia in 11.4% (n = 33), atrophy in 11.4% (n = 33), and lymphoid follicles in 21.1% (n = 61) of the patients. Within H. pylori-positive patients, the ratio of CagA positivity was 57.3% (n = 122). Low B12 vitamin level was significantly correlated with existence of H. pylori (p=0.02), CagA (p=0.002), lymphocyte (p=0.006), metaplasia (p=0.001), atrophy (p=0.001), and lymphoid follicles (p=0.006). Positivity of CagA has been detected to be statistically corelated with lymphocyte (p=0.001) and activation (p=0.005); however, the same relation was not present with atrophy (p=0.236).

Conclusion

In conclusion, B12 deficiency was positively correlated with CagA positivity and gastric inflammatory activity.

Are optic nerve heads of patients with helicobacter pylori infection more susceptible to glaucomatous damage?

BACKGROUND

To compare retinal nerve fiber layer thicknesses (RNFLT) of patients with or without Helicobacter pylori infection and to reveal the possible RNFLT changes after H. pylori eradication.

MATERIALS AND METHODS

Sixty-five eyes of 65 patients that tested positive for H. pylori (Group 1) and 48 eyes of 48 patients that tested negative for H. pylori (Group 2) were included. RNFLT analyses were performed with spectral-domain (SD) optical coherence tomography (OCT) in a total of five regions: the superior, inferior, nasal, and temporal quadrants and the average. Then, a comparison was made between groups. After H. pylori eradication in 38 patients, RNFLTs were compared with both pre-eradication values and Group 2.

RESULTS

The groups were similar in terms of age and gender. Temporal quadrant RNFLT was thinner in Group 1 than in Group 2 (P=.02). After H. pylori eradication, RNFLTs did not differ from pre-eradication values in Group 1 (P>.05 for all), whereas temporal quadrant RNFLT after H. pylori eradication was thinner compared to Group 2 (P=.03).

CONCLUSIONS

H. pylori may cause the localized defects on RNFL that are the early signs of glaucoma.

Gastric parietal cell antibodies, Helicobacter pylori infection, and chronic atrophic gastritis: evidence from a large population-based study in Germany

BACKGROUND

Striking similarities between autoimmune gastritis and Helicobacter Pylori (H. pylori)-associated gastritis have suggested a potential link between these two pathologic conditions in the progression of chronic atrophic gastritis (CAG); however, evidence has remained conflicting.

METHODS

Serum pepsinogen I and II, and antibodies against H. pylori in general, the cytotoxin-associated gene A protein (CagA) and parietal cells were measured by ELISA in 9,684 subjects aged 50 to 74 years. Antigastric parietal cell antibody (APCA) prevalence was examined in the overall population and according to sex, age, and H. pylori serostatus. The association between APCA prevalence and CAG was assessed by logistic regression, overall and according to H. pylori status, controlling for potential confounding factors.

RESULTS

Overall APCA prevalence was 19.5%. APCA prevalence was strongly associated with CAG, and the association was increasing with increasing severity of CAG. Furthermore, the association between APCA and CAG was even stronger among H. pylori-negative subjects [odds ratio (OR) = 11.3; 95% confidence interval (CI): 7.5-17.1)] than among H. pylori-positive subjects (OR = 2.6; 95% CI: 2.1-3.3).

CONCLUSIONS

APCA may play a role on the development of gastric atrophy, irrespective of H. pylori infection.

IMPACT

Assessment of APCA might be a useful complement to established markers (such as pepsinogens and H. pylori antibodies) in screening for CAG.

Control of gastric acid secretion in health and disease

Recent milestones in the understanding of gastric acid secretion and treatment of acid-peptic disorders include the (1) discovery of histamine H(2)-receptors and development of histamine H(2)-receptor antagonists, (2) identification of H(+)K(+)-ATPase as the parietal cell proton pump and development of proton pump inhibitors, and (3) identification of Helicobacter pylori as the major cause of duodenal ulcer and development of effective eradication regimens. This review emphasizes the importance and relevance of gastric acid secretion and its regulation in health and disease. We review the physiology and pathophysiology of acid secretion as well as evidence regarding its inhibition in the management of acid-related clinical conditions.

A Sick Eye in a Sick Body? Systemic Findings in Patients with Primary Open-angle Glaucoma

Despite intense research, the pathogenesis of primary open-angle glaucoma (POAG) is still not completely understood. There is ample evidence for a pathophysiological role of elevated intraocular pressure; however, several systemic factors may influence onset and progression of the disease. Systemic peculiarities found in POAG include alterations of the cardiovascular system, autonomic nervous system, immune system, as well as endocrinological, psychological, and sleep disturbances. An association between POAG and other neurodegenerative diseases, such as Alzheimer disease and Parkinson disease, has also been described. Furthermore, the diagnosis of glaucoma can affect the patient's quality of life. By highlighting the systemic alterations found in POAG, this review attempts to bring glaucoma into a broader medical context.

Association between Helicobacter pylori infection and acute inflammatory demyelinating polyradiculoneuropathy

The aim of this study was to investigate a possible association between Helicobacter pylori infection and acute inflammatory demyelinating polyradiculoneuropathy (AIDP). Of 17 consecutive patients with Guillain-Barre syndrome (GBS), 13 patients (six females; mean age 50 +/- 24 years) with AIDP were investigated. Clinical status was evaluated according to Hughes' score, and electrophysiological tests were performed within 2 weeks from disease onset. Helicobacter pylori infection was detected histologically and serum H. pylori-specific IgG antibodies were analysed by ELISA. Twenty asymptomatic patients (12 females; mean age 63 +/- 8 years), undergoing upper gastrointestinal endoscopy for investigation of mild iron deficiency anaemia, served as controls. Helicobacter pylori was found in 12 of 13 AIDP patients (92%), and in 10 of 20 controls (50%), (P = 0.02). Electrophysiological studies showed demyelination in all AIDP patients. High levels of anti-H. pylori IgG antibodies correlated with advanced clinical status. Five of seven AIDP patients with high levels of anti-H. pylori IgG antibodies had delayed F-wave latencies, indicating affection of proximal segments of peripheral nerves. Helicobacter pylori infection seems to be more frequent in AIDP patients. Anti-H. pylori titre might reflect advanced clinical status. Anti-H. pylori IgG antibodies are also associated with involvement of the proximal parts of peripheral nerves in AIDP.

Apoptosis and autoimmunity as proposed pathogenetic links between Helicobacter pylori infection and idiopathic achalasia

Achalasia is a disorder of the oesophagus characterised by increased lower oesophageal sphincter (LOS) tone, lack of LOS relaxation with swallowing and aperistalsis of the body of the oesophagus. The aetiology and pathogenesis of idiopathic achalasia are still unclear, although a viral cause, genetic influences (associations with HLA loci) and autoimmune processes have been postulated. Degeneration and significant loss of nerve fibres, associated with an inflammatory infiltrate of the myenteric plexus in idiopathic achalasia, provide evidence of an immune mediated destruction of the myenteric plexus, possibly through apoptotic process. This concept is reinforced by the concomitant appearance of achalasia and Guillain-Barré syndrome (GBS) and/or Parkinson's disease, where inappropriate initiation of apoptosis has been proposed to underlie the neuronal attrition. In the same respect, Helicobacter pylori (H. pylori) infection has been associated with gastric autoimmunity, and patients infected with H. pylori have been shown to possess autoantibodies that cross-react with antigens expressed on the gastric mucosa. Furthermore, H. pylori is thought to be associated with the development of autoimmune sequelae observed in peripheral neuropathies and GBS, where autoantibodies to specific neural targets have been found to impair native neural function by inducing nerve tissue damage, possibly by apoptosis. Taken together, we assume that H. pylori infection might be a pathogenetic factor of achalasia through induction of autoimmunity and apoptosis. Whether eradication of H. pylori infection may indirectly offer benefit to the pathophysiology of idiopathic achalasia by ameliorating the apoptotic loss of ganglion cells and their axons in the oesophageal wall remains to be elucidated.

Helicobacter pylori associated antigastric autoantibodies: role in Sjögren's syndrome gastritis

BACKGROUND

Previous studies have shown that Helicobacter pylori seroprevalence in Sjögren's syndrome is comparable with that of the general population. However, the origin of the chronic gastropathy associated with this syndrome and the role of local autoimmunity--possibly triggered by bacterial infection--in its pathogenesis remain unclear.

MATERIALS AND METHODS

We initially determined the prevalence of IgG anti H. pylori in dyspeptic subjects with and without Sjögren's syndrome. In subsets of both groups we then determined anti CagA and human tissue-tested anticanalicular/antifoveolar autoantibodies. We also compared activity, atrophy and Mucosa Associated Lymphoid Tissue (MALT) scores, as well as symptoms, before and after bacterial eradication.

RESULTS

Prevalence of H. pylori in Sjögren's syndrome patients was similar to controls: 31/54 (57%) vs. 93/150 (62%). Anti CagA prevalence was also similar in the two groups. Twenty weeks after H. pylori eradication, histological activity decreased in both groups, however, atrophy and MALT decreased significantly only in controls. Sixteen months after H. pylori eradication, 75% of Sjögren's syndrome patients still complained of dyspepsia compared with 13% of controls. Finally, antigastric autoantibodies were present in 29% of tested Sjögren's syndrome patients vs. 28% of controls.

CONCLUSIONS

H. pylori infection was equally prevalent among dyspeptic Sjögren's syndrome patients and dyspeptic controls. Likewise, there were no differences regarding anti CagA prevalence or antigastric autoantibodies among the two groups. The persistence of symptoms as well as of the lymphocytic infiltration and atrophy after H. pylori eradication in Sjögren's syndrome may underlie the 'endogenous' and still unknown nature of the gastropathy in this condition.

Impact of Helicobacter pylori on the development of vitamin B12 deficiency in the absence of gastric atrophy

BACKGROUND

Cobalamin (vitamin B12) deficiency is associated with Helicobacter pylori infection. This study examined how serum vitamin B12 levels relate to gastric mucosa H. pylori density and histology, and to hematological findings in patients with minimal or no gastric atrophy. A second aim was to confirm that H. pylori eradication therapy increases serum B12.

MATERIALS AND METHODS

Biopsies of the gastric mucosa from a population of dyspeptic patients were graded for level of chronic inflammation, neutrophil activity, atrophy, and H. pylori density. A total of 145 H. pylori-infected patients with minimal or no atrophy were included in the study. Serum cobalamin level, hemoglobin level, and mean corpuscular volume were measured in the 145 patients before eradication therapy, and in 65 of the subjects after treatment. The hematologic findings before and after eradication therapy and correlations between serum vitamin B12 level and histologic parameters, hematologic findings, and patient age were statistically analyzed.

RESULTS

There was no significant correlation between serum cobalamin level and patient age. Before treatment all the histopathological scores were inversely correlated with serum vitamin B12 level (p <.01) on univariate analysis. Only H. pylori density was significantly associated with B12 level on multivariate analysis. Serum hemoglobin and cobalamin levels were significantly increased after treatment, regardless of H. pylori eradication status (p <.001).

CONCLUSION

The findings provide strong evidence that H. pylori infection is associated with cobalamin deficiency, and show that this is true even in patients with non-ulcer dyspepsia and minimal or no gastric atrophy.

Review article: Helicobacter pylori infection from pathogenesis to treatment--a critical reappraisal

The main areas of this review are Helicobacter pylori and disease pathogenesis; the relationship of H. pylori to lower gastrointestinal diseases, liver disease and extra-gastrointestinal conditions; the relationship of H. pylori to gastro-oesophageal reflux disease; infection in the very young and very old; diagnostic techniques; and management of H. pylori infections with particular emphasis on eradication regimens and antibiotic resistance.

Helicobacter: a paradigm shift in peptic ulcer disease and more?

There are many diseases where the cause is unknown and this makes a specific treatment difficult. In many cases all that can be achieved is amelioration of the illness. Peptic ulcer disease was one such condition no more that 20 years ago. The management was drastic--either an operation or life-long medication in order to reduce the acid secreted by the stomach. However, the cause of this condition was discovered in 1983. Although initially sceptical, the medical fraternity now almost universally endorse Helicobacter pylori as the cause of the majority of stomach ulcers. Peptic ulcers can now be cured by antibiotics. This is a major shift in medical practice. Continued investigations on Helicobacter pylori are bringing to light other possible associations with disease as well as delineating plausible biological mechanisms for disease pathogenesis.

Gastric secretion

The influence of central and peripheral stimuli on gastric acid secretion is mediated via activation of histaminergic, gastrinergic, and cholinergic pathways coupled to intracellular second-messenger systems that determine the trafficking and activity of H+ K+-ATPase, the proton pump of the parietal cell. Histamine, released from enterochromaffin-like cells stimulates the parietal cell directly via H-2 receptors coupled to generation of cAMP. Gastrin, acting via cholecystokinin-2 receptors on enterochromaffin-like cells coupled to an increase in intracellular calcium, stimulates the parietal cell indirectly by activating histidine decarboxylase, releasing histamine, and inducing enterochromaffin-like cell hypertrophy and hyperplasia. Acetylcholine, released from gastric postganglionic intramural neurons, stimulates the parietal cell directly via M-3 receptors coupled to intracellular calcium release and calcium entry. The second-messenger systems activated in the parietal cell converge on H+ K+-ATPase that catalyzes the exchange of luminal K+ for cytoplasmic H+ and is responsible for gastric luminal acidification. The main inhibitor of acid secretion is somatostatin which, acting via sst2 receptors, exerts a tonic inhibitory influence on parietal, enterochromaffin-like, and gastrin cells. Acute infection with Helicobacter pylori results in hypochlorhydria, whereas chronic infection may be associated with either hypo- or hyperchlorhydria. Although prostaglandins are thought to play a physiologic role in the regulation of acid secretion and maintenance of gastric mucosal integrity, the precise roles of cyclooxygenase-1 and cyclooxygenase-2 in these processes still eludes us.