Reliability of Helicobacter pylori and CagA serological assays

Helicobacter pylori, Vascular Risk Factors and Cognition in U.S. Older Adults

Previous studies suggested that Helicobacter pylori infection could be a risk factor for stroke, dementia, and Alzheimer's disease (AD). The authors examined data from participants, 60 years old and older in the Third National Health and Nutrition Examination Survey (NHANES-III) to assess the relation between Helicobacter pylori infection and results of the Mini-Mental State Examination (n = 1860) using logistic regression analysis controlling for age, gender, race/ethnicity, education, poverty and history of medically diagnosed diabetes. Moreover, we examined performance on the digit-symbol substitution test (DSST) of 1031 participants in the 1999-2000 NHANES according to their H. pylori infection status controlling for potential confounders using multiple linear regression analyses. In 1988-1991, older adults infected with CagA strains of H. pylori had a 50% borderline statistically significant increased level of cognitive impairment, as measured by low Mini-Mental State Examination (MMSE) scores (age-education adjusted prevalence ratio: 1.5; 95% confidence interval: 1.0, 2.0). In 1999-2000, older US adults infected with H. pylori scored 2.6 fewer points in the DSST than those uninfected (mean adjusted difference: -2.6; 95% confidence interval -5.1, -0.1). The authors concluded that H. pylori infection might be a risk factor for cognitive decline in the elderly. They also found that low cobalamin and elevated homocysteine were associated with cognitive impairment.

Augmentation of Autoantibodies by Helicobacter pylori in Parkinson's Disease Patients May Be Linked to Greater Severity

Parkinson's disease (PD) is the second most common chronic and progressive neurodegenerative disorder. Its etiology remains elusive and at present only symptomatic treatments exists. Helicobacter pylori chronically colonizes the gastric mucosa of more than half of the global human population. Interestingly, H. pylori positivity has been found to be associated with greater of PD motor severity. In order to investigate the underlying cause of this association, the Sengenics Immunome protein array, which enables simultaneous screening for autoantibodies against 1636 human proteins, was used to screen the serum of 30 H. pylori-seropositive PD patients (case) and 30 age- and gender-matched H. pylori-seronegative PD patients (control) in this study. In total, 13 significant autoantibodies were identified and ranked, with 8 up-regulated and 5 down-regulated in the case group. Among autoantibodies found to be elevated in H. pylori-seropositive PD were included antibodies that recognize Nuclear factor I subtype A (NFIA), Platelet-derived growth factor B (PDGFB) and Eukaryotic translation initiation factor 4A3 (eIFA3). The presence of elevated autoantibodies against proteins essential for normal neurological functions suggest that immunomodulatory properties of H. pylori may explain the association between H. pylori positivity and greater PD motor severity.

A case of Helicobactor pylori negative low-grade gastric MALT lymphoma in an elderly female, successfully treated with rituximab

PATIENT

Female, 91 FINAL DIAGNOSIS: Low-grade gastric MALT lymphoma Symptoms: Recurrent epigastric and right upper quadrant dyscomfort Medication: Rituximab Clinical Procedure: esophagogastroduodenoscopy • gastric biopsy Specialty: Gastroenterology.

OBJECTIVE

Unusual or unexpected effect of treatment.

BACKGROUND

Mucosa associated lymphoid tissue (MALT) lymphoma can occur in any extranodal organ or tissue, stomach being the common site. Most of the gastric MALT lymphomas are related to chronic H. pylori infection. H. pylori negative gastric MALT lymphoma is relatively uncommon and usually treated with a short course of chemotherapy, radiotherapy or surgery.

CASE REPORT

Herein, we present a case of an elderly female with H. pylori negative, low-grade gastric MALT lymphoma that was successfully treated with a short course of rituximab.

CONCLUSIONS

This case report emphasizes that rituximab monotherapy can be an effective treatment for H. pylori negative low grade gastric MALT lymphoma especially in an elderly patient where surgery or radiotherapy may not be appropriate.

Helicobacter pylori infection, chronic inflammation, and genomic transformations in gastric MALT lymphoma

Nowadays, it is believed that the main role in the development of gastric mucosa-associated lymphoid tissue (MALT) lymphoma plays Helicobacter pylori infection. This world-wide distributed bacteria is in charge of most cases of not only upper gastrointestinal tract disorders but also some of extragastric problems. Constant stimulation of the immune system causes a B-lymphocytes proliferation, which is considered to be responsible for the neoplastic transformation. On the other hand, there are 10%–20% of patients who do not respond to Helicobacter pylori eradication treatment. This group has often a chromosome translocation, which suggests that there is another unknown, so far, pathogenetic mechanism of MALT lymphoma. Majority of genetic abnormalities are connected with nuclear factor-κB (NF-κB) pathway, which activates the uncontrolled proliferation of neoplastic cells. Translocations already described in studies are t(11;18)(q21;q21), which is the most common, t(14;18)(q32;q21), t(14;18)(q32;q21), and t(3;14)(p14.1;q32). This non-Hodgkin's lymphoma is an indolent type originated outside lymph nodes. In more than 50% of cases, it occurs in the stomach. Occasionally, it can be found in salivary and thyroid gland, lung, breast, bladder, skin, or any other place in the human body. This paper is a review of the current knowledge on etiology, pathogenesis, treatment, and follow-up of gastric MALT lymphoma.

The impact of Helicobacter pylori on atopic disorders in childhood

BACKGROUND

 The prevalence of Helicobacter pylori in Western populations has steadily decreased. This has been suggested as one of the factors involved in the recent increase of asthma and allergy. Some studies have reported a negative association between H. pylori and asthma and allergy, but data are inconsistent and there are a few studies in children.

AIM

 We investigated whether the prevalence of H. pylori was associated with asthma symptoms, allergic rhinitis, and atopic dermatitis in childhood.

METHODS

 We determined IgG anti-H. pylori and CagA antibodies in serum of Dutch children, who took part in the PIAMA birth cohort study. Serum was collected from 545 children, aged 7-9 years (Dutch ethnicity 91.5%). Symptoms of asthma and atopy were assessed by yearly questionnaires. Chi-square tests and logistic regression were used.

RESULTS

 We found 9%H. pylori and 0.9% CagA seropositivity. Twelve (5.9%) children with reported wheezing ever were H. pylori positive, compared to 37 (10.9%) of the non-wheezers (p = .05). No significant differences in H. pylori prevalence were found between children with or without allergic rhinitis (8.5% vs 9.5%), atopic dermatitis (8.7% vs 9.2%), and physician-diagnosed asthma (7.1% vs 9.4%). Multivariate analysis showed no significant associations between H. pylori seropositivity and wheezing (OR 0.52; 95% CI 0.25-1.06), allergic rhinitis (OR 0.96; 95% CI 0.51-1.81), atopic dermatitis (OR 1.05; 95% CI 0.56-1.98) or physician-diagnosed asthma (OR 0.87; 95% CI 0.37-2.08).

CONCLUSION

 We found a borderline significantly lower H. pylori seropositivity in children with wheezing compared to non-wheezers, but no association between H. pylori serum-antibody status and allergic rhinitis, atopic dermatitis, or asthma.

Asthma is inversely associated with Helicobacter pylori status in an urban population

Background

Microbial exposures have been suggested to confer protection from allergic disorders and reduced exposures to gastrointestinal microbiota have been proposed as an explanation for the increase in asthma prevalence. Since the general prevalence of Helicobacter pylori has been decreasing, we hypothesized that H. pylori serostatus would be inversely related to the presence of asthma.

Methods

Adults were recruited to participate in the New York University (NYU)/Bellevue Asthma Registry in New York City. Adult asthma cases (N = 318) and controls (N = 208) were identified and serum IgG antibodies to H. pylori whole cell antigens or the immunodominant CagA antigen were measured.

Results

As expected, the asthma cases and controls differed with respect to atopy and lung function. Seropositivity to H. pylori or CagA antigen was present in 47.1% of the total case and control study population. Asthma was inversely associated with CagA seropositivity (OR = 0.57, 95% CI = 0.36–0.89). Median age of onset of asthma (doctor's diagnosis) was older (21 years) among individuals with CagA+ strains than among H. pylori- individuals (11 years) (p = 0.006).

Conclusion

These data are consistent with the hypothesis that colonization with CagA+ H. pylori strains is inversely associated with asthma and is associated with an older age of asthma onset in an urban population. The data suggest H. pylori as a marker for protection.

Trial Registration

ClinicalTrials.gov NCT00212537

Helicobacter pylori and gastroesophageal reflux disease: a case-control study

BACKGROUND

Gastric colonization with Helicobacter pylori is a proposed protective factor against gastroesophageal reflux disease (GERD), but little population-based data exist and other data conflict.

METHODS

We conducted a case-control study within the membership of a large integrated health-care system that compared GERD-free subjects with two groups: subjects with a physician-assigned GERD diagnosis and randomly selected members with self-described weekly GERD symptoms. Subjects completed interviews, GERD questionnaires, and antibody testing for H. pylori and its cagA protein.

RESULTS

Serologic data were available for 301 physician-assigned GERD patients, 81 general membership subjects with GERD symptoms, and 175 general membership subjects without GERD symptoms. Physician-assigned GERD patients were less likely to have H. pylori antibodies than GERD-free member controls (odds ratio (OR) = 0.27, 95% confidence interval (CI) 0.15-0.47); there was also an inverse association between H. pylori and GERD symptom severity (OR = 0.18, 95% CI 0.08-0.41; severe or very severe symptoms) and GERD frequency (OR = 0.18, 95% CI 0.09-0.38; for symptoms at least weekly). The association was stronger among persons with erosive GERD and was similar between H. pylori-positive subjects with and without cagA. There was no association among persons who were cagA positive, but H. pylori negative. Similar findings were found in analyses of the general membership with self-described GERD symptoms.

CONCLUSIONS

H. pylori antibody status was inversely associated with a GERD diagnosis and GERD symptoms compared with a general membership population.

Therapy of gastric mucosa associated lymphoid tissue lymphoma

Gastric mucosa associated lymphoid tissue (MALT) lymphoma has recently been incorporated into the World Health Organization (WHO) lymphoma classification, termed as extranodal marginal zone B-cell lymphoma of MALT-type. In about 90% of cases this lymphoma is associated with H pylori infection which has been clearly shown to play a causative role in lymphomagenesis. Although much knowledge has been gained in defining the clinical features, natural history, pathology, and molecular genetics of the disease in the last decade, the optimal treatment approach for gastric MALT lymphomas, especially locally advanced cases, is still evolving. In this review we focus on data for the therapeutic, stage dependent management of gastric MALT lymphoma. Hence, the role of eradication therapy, surgery, chemotherapy and radiotherapy is critically analyzed. Based on these data, we suggest a therapeutic algorithm that might help to better stratify patients for optimal treatment success.

Early-life family structure and microbially induced cancer risk

BACKGROUND

Cancer may follow exposure to an environmental agent after many decades. The bacterium Helicobacter pylori, known to be acquired early in life, increases risk for gastric adenocarcinoma, but other factors are also important. In this study, we considered whether early-life family structure affects the risk of later developing gastric cancer among H. pylori+ men.

METHODS AND FINDINGS

We examined a long-term cohort of Japanese-American men followed for 28 y, and performed a nested case-control study among those carrying H. pylori or the subset carrying the most virulent cagA+ H. pylori strains to address whether family structure predicted cancer development. We found that among the men who were H. pylori+ and/or cagA+ (it is possible to be cagA+ and H. pylori- if the H. pylori test is falsely negative), belonging to a large sibship or higher birth order was associated with a significantly increased risk of developing gastric adenocarcinoma late in life. For those with cagA+ strains, the risk of developing gastric cancer was more than twice as high (odds ratio 2.2; 95% confidence interval 1.2-4.0) among those in a sibship of seven or more individuals than in a sibship of between one and three persons.

CONCLUSIONS

These results provide evidence that early-life social environment plays a significant role in risk of microbially induced malignancies expressing five to eight decades later, and these findings lead to new models to explain these interactions.

The best method of detecting prior Helicobacter pylori infection

AIM

Prior Helicobacter pylori (H pylori) infection has often been underestimated. These underestimations have misled physicians attempting to determine the significance between H pylori and certain gastrointestinal lesions such as intestinal metaplasia, atrophic gastritis, and gastric cancer. Our study endeavored to detect past H pylori infections accurately, easily, and rapidly with the newly developed immunoblot kit, Helico Blot 2.1.

METHODS

Thirty-three patients, including 25 H pylori infected and 8 uninfected cases, were enrolled in our study. All patients received consecutive gastroendoscopic examinations and (13)C-urea breath test (UBT) tests at 6- or 12-mo intervals for up to 4 years. Serum samples were obtained from each patient at the same time. Intragastric H pylori infection was confirmed in accordance with the gold standard. Twenty-five H pylori-infected patients received triple therapies after initial bacterial confirmation, and were successful in eradicating their infections. Serially obtained sera were tested by means of Helico Blot 2.1.

RESULTS

Current infection marker detected by Helico Blot 2.1 was unreliable for representing ongoing H pylori infection. Only 35 and 37 ku antibodies of H pylori had significant seroconversion rates 1 year after having been cured. The seropositive rates of 116 ku (cytotoxin-associated antigen (CagA)) and Helico Blot 2.1 were nearly 100% during 4-year follow-up period. Both CagA antigen and Helico blot 2.1 could serve as indicators of long-term H pylori infection.

CONCLUSION

Helico Blot 2.1 can detect past H pylori infections for up to 4 years, and is the best method to date for detecting previous long-term H pylori infection.

Is Helicobacter pylori seropositivity related to body mass index in the United States?

BACKGROUND

Helicobacter pylori infection may decrease serum ghrelin and increase gastric leptin levels, which may, in turn, decrease body mass index.

AIM

To determine whether H. pylori seropositivity is associated with body mass index.

METHODS

Serum H. pylori and cytotoxin-associated gene product A (CagA) antibody levels were measured on 6724 adult participants of the third National Health and Nutrition Examination Survey (1988-91). We evaluated the association between H. pylori/CagA antibody status [both negative (-/-), H. pylori-positive/CagA-negative (+/-), or both positive (+/+)] and body mass index, adjusting for sociodemographic factors. We also investigated whether H. pylori/cytotoxin-associated gene product A antibody status was associated with fasting serum leptin levels.

RESULTS

H. pylori/CagA antibody status was not associated with obesity (body mass index > or = 30 kg/m(2)) [adjusted odds ratio (OR) 1.2, 95% CI: 0.9-1.6 comparing (+/+) to (-/-) and adjusted OR 1.1, 95% CI: 0.8-1.5 comparing (+/-) to (-/-)], overweight (body mass index 25 to <30 kg/m(2)) [adjusted OR 1.0, 95% CI: 0.7-1.2 comparing (+/+) to (-/-) and adjusted OR 1.0, 95% CI: 0.8-1.3 comparing (+/-) to (-/-)], or fasting serum leptin level in the USA population.

CONCLUSIONS

H. pylori seropositivity and CagA antibody status are not associated with body mass index or fasting serum leptin level.