H. pylori Link to Stomach Cancer Strengthened

MedicalResearch.com Interview with:

Nina R. Salama. PhD Member Human Biology Division Member Public Health Sciences Division Affiliate Member Basic Sciences Division Dr. Penny E. Petersen Memorial Chair for Lymphoma Research  Director of Molecular and Cellular Biology (MCB) Graduate Program Fred Hutchinson Cancer Research Center

Dr. Salama

Nina R. Salama. PhD
Member Human Biology Division
Member Public Health Sciences Division
Affiliate Member Basic Sciences Division
Dr. Penny E. Petersen Memorial Chair for Lymphoma Research
Director of Molecular and Cellular Biology (MCB) Graduate Program
Fred Hutchinson Cancer Research Center 

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: We wanted to better understand why certain patients infected with H. pylori developed stomach cancer and how we could better identify them. H. pylori is one of the strongest risk factors for stomach cancer, but how much it predisposes individuals to gastric cancer varies around the world.

Working closely with colleagues from Zhengzhou University, we ran tests on 49 samples from China and found that 91 percent of patients infected with the EPIYA D gene variant of H. pylori also had stomach cancer. Continue reading

H. pylori Treated With Clarithromycin Linked To Transient Neuropsychiatric Events

MedicalResearch.com Interview with:
Dr Esther W Chan PhD
Assistant Professor
Research Lead, Centre for Safe Medication Practice and Research
Department of Pharmacology and Pharmacy
Li Ka Shing Faculty of Medicine
The University of Hong Kong

MedicalResearch.com: What is the background for this study?

Dr. Chan: In the past decades, numerous case reports suggested that clarithromycin might induce neuropsychiatric events including psychotic manifestations and cognitive disturbances. Neuropsychiatric safety concerns are also listed for clarithromycin in British National Formulary in the United Kingdom and Physicians’ Desk Reference in the United States. Recent case reports also described neuropsychiatric cases relating to clarithromycin based H pylori therapy. However, the association remained unclear as there was no population-based observational study to examine the association. Therefore, we conducted a population-based observational study for investigating the neuropsychiatric safety of H pylori therapy containing clarithromycin.

MedicalResearch.com: What are the main findings?

Dr. Chan: We conducted a population-based observational study using self-controlled case series and nested case-control study designs to investigate the association between H pylori therapy containing clarithromycin and neuropsychiatric events. The result showed a 4-fold increased risk of neuropsychiatric events during current use of H pylori therapy containing clarithromycin. However, the risk did not persist after the end of H pyloritherapy.

MedicalResearch.com: What should clinicians and patients take away from your report?

Dr. Chan: Patients who are prescribed H pylori therapy containing clarithromycin should be monitored for the transient neuropsychiatric events so that preventable psychiatric interventions can be avoided.

MedicalResearch.com: What recommendations do you have for future research as a result of this study?

Dr. Chan: Not only does H pylori therapy contain clarithromycin, but also other ingredients such as amoxicillin or metronidazole and proton pump inhibitors. Therefore, we could not entirely rule out the possible neuropsychiatric effects of other drugs in our study. It is important to conduct future studies concerning neuropsychiatric safety on these drugs as they are widely prescribed in clinical settings. 

MedicalResearch.com: Thank you for your contribution to the MedicalResearch.com community.

Citation:

Wong AS, Wong IK, Chui CL, et al. Association Between Acute Neuropsychiatric Events and Helicobacter pylori Therapy Containing Clarithromycin.JAMA Intern Med. Published online May 02, 2016. doi:10.1001/jamainternmed.2016.1586.

Note: Content is Not intended as medical advice. Please consult your health care provider regarding your specific medical condition and questions.

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Could H pylori Be Protective Against Multiple Sclerosis?

Allan G Kermode MBBS MD FRACP FRCP Clinical Professor of Neuroimmunology, Murdoch University Clinical Professor of Neurology, University of Western Australia Head, Department of Neurology and Clinical Neurophysiology SCGH Centre for Neuromuscular and Neurological Disorders Australian Neuromuscular Research Institute Sir Charles Gairdner Hospital Perth WA Australia Institute of Immunology and Infectious Diseases Murdoch University, Western AustraliaMedicalResearch.com Interview with:
Allan G Kermode MBBS MD FRACP FRCP

Clinical Professor of Neuroimmunology, Murdoch University
Clinical Professor of Neurology, University of Western Australia
Head, Department of Neurology and Clinical Neurophysiology SCGH
Centre for Neuromuscular and Neurological Disorders
Australian Neuromuscular Research Institute  Sir Charles Gairdner Hospital Perth WA Australia Institute of Immunology and Infectious Diseases
Murdoch University, Western Australia

MedicalResearch: You found that H. pylori sero-positivity was significantly lower in female patients with MS than in female healthy controls, but you didn’t find such a trend in men with Multiple Sclerosis… Briefly, what might explain this association between H. pylori and Multiple Sclerosis in women? (i.e the hygiene hypothesis I suppose?).

Prof. Kemode: There are a number of possible explanations, but we believe that the most likely is that helicobacter colonisation is a surrogate marker for the baseline levels of exposure to environmental pathogens and organisms during childhood. We have argued this point of view in our manuscript. It should be emphasised that perhaps not all exposure to infectious agents need necessarily be pathogenic, and the concept of the protobiome is an important one. Every healthy (and unhealthy) individual is host to very many organisms, with the gut having the widest diversity. Other explanations for the association might include that there is some specific antigenic interaction occurring promoting specific immune tolerance to CNS antigens, but I believe that this conclusion would be drawing a very long bow with our current stage of knowledge regarding Multiple Sclerosis.

MedicalResearch: Why does this relationship exist in women but not in men? (presumably, they are exposed to the same sanitation, hygiene etc.)

Prof. Kemode: This is arguably one of the most fascinating observations of our study. Historically the sex ratio in Multiple Sclerosis was equal, yet in the last 100 years the prevalence of Multiple Sclerosis has increased markedly and the majority of this increase has occurred in women such that in Australia the sex ratio F:M approximates 3:1. The fact that over the same period prevalence of helicobacter in Western countries has declined markedly is a tantalising observation. At this stage scientific knowledge has not explained the changing sex ratios in Multiple Sclerosis nor can we yet explain the strong helicobacter association in females but not males in our study, but our study provides useful navigation to direct further research.

Continue reading

Study Suggests Link Between H. pylori Bacteria and Blood Sugar Control in Adult Type II Diabetes

Newswise — NEW YORK, March 14, 2012 – A new study by researchers at NYU Langone Medical Center reveals that the presence of Helicobacter pylori (H. pylori) bacteria is associated with elevated levels of glycosylated hemoglobin (HbA1c), an important biomarker for blood glucose levels and diabetes. The association was even stronger in obese individuals with a higher Body Mass Index (BMI). The results, which suggest the bacteria may play a role in the development of diabetes in adults, are available online in The Journal of Infectious Diseases.

There have been several studies evaluating the effect of the presence of H. pylori on diabetes outcomes, but this is the first to examine the effect on HbA1c, an important, objective biomarker for long-term blood sugar levels, explained Yu Chen, PhD, MPH, associate professor of epidemiology at NYU School of Medicine, part of NYU Langone Medical Center.

“The prevalence of obesity and diabetes is growing at a rapid rate, so the more we know about what factors impact these conditions, the better chance we have for doing something about it,” Dr. Chen said. Looking at the effects of H. pylori on HbA1c, and whether the association differs according to BMI status, provided what could be a key piece of information for future treatment of diabetes, she explained.

Type II diabetes causes an estimated 3.8 million adult deaths globally. There have been conflicting reports about the association between H. pylori infection and type II diabetes. To better understand the relationship between H. pylori and the disease, Dr. Chen and Martin J. Blaser, MD, the Frederick H. King Professor of Internal Medicine and professor of microbiology, analyzed data from participants in two National Health and Nutrition Surveys (NHANES III and NHANES 1999-2000) to assess the association between H. pylori and levels of HbA1c.

“Obesity is an established risk factor for diabetes and it is known that high BMI is associated with elevated HbA1c. Separately, the presence of H. pylori is also associated with elevated HbA1c,” said Dr. Blaser, who has studied the bacteria for more than 20 years. “We hypothesized that having both high BMI and the presence of H. pylori would have a synergistic effect, increasing HbA1c even more than the sum of the individual effect of either risk factor alone. We now know that this is true.”

H. pylori lives in the mucous layer lining the stomach where it persists for decades. It is acquired usually before the age of 10, and is transmitted mainly in families. Dr. Blaser’s previous studies have confirmed the bacterium’s link to stomach cancer and elucidated genes associated with its virulence, particularly a gene called cagA.

Regarding H. pylori’s association with elevated HbA1c, Drs. Chen and Blaser believe the bacterium may affect the levels of two stomach hormones that help regulate blood glucose, and they suggest that eradicating H. pylori using antibiotics in some older obese individuals could be beneficial.

More research will be needed to evaluate the health effects of H. pylori and its eradication among different age groups and in relation to obesity status, the authors noted.

“If future studies confirm our finding, it may be beneficial for individuals at risk for diabetes to be tested for the presence of H. pylori and, depending on the individual’s risk factor profile” Dr. Chen.

In an accompanying editorial in The Journal of Infectious Diseases, Dani Cohen, PhD, of Tel Aviv University in Israel, pointed out that while previous studies have addressed the association between type II diabetes and H. pylori in small samples, this study analyzed two independent large national samples of the general population. Dr. Cohen agreed with the study authors, suggesting that adults infected with H. pyloriwith higher BMI levels, even if asymptomatic, may need anti-H. pylori therapy to control or prevent type II diabetes. If the study findings are confirmed, Dr. Cohen wrote, they “could have important clinical and public health implications.”