Help
Subscribe


GastroHep.com - the global online resource for all aspects of gastroenterology, hepatology and endoscopy

 23 February 2018

Advanced search
GastroHep.com - the global online resource for all aspects of gastroenterology, hepatology and endoscopy Profile of Roy Pounder

Home

News  
Journals
Review Articles
Slide Atlas
Video Clips
Online Books
Advanced Digestive Endoscopy
Classical Cases
Conference Diary
PubMed
International GH Links
USA GH Links
National GH Links
National GI Societies
Other Useful Links




Emails on Gastroenterology and Hepatology
the National AIDS Treatment Advocacy Project
Visit the gastroenterology section of the EUMS

News

Hepatitis A virus link to atopic disease

A declining prevalence of hepatitis A virus infection may contribute to an increase in atopic disease, find researchers in this week's issue of Nature.

News image

fiogf49gjkf04

Atopic diseases, such as asthma, allergic rhinitis and dermatitis, are caused by a combination of environmental and genetic factors.

Exposure to HAV is associated with poor hygiene, large family size and attendance at day-care centers. These are all factors which are inversely associated with atopy.

In this study, researchers from the United States determined that that infection by hepatitis A virus (HAV) may protect individuals from atopy.

Infection with HAV may have protected many individuals against atopy.
Nature

The research team identified TIM-1 as a candidate gene for atopy and asthma in a region of mouse chromosome 11. This is homologous to a segment of human chromosome 5q31–33 that has been linked to atopy.

The team investigated whether the interaction between HAV and TIM-1 on lymphocytes can modify T cells in a way that protects against atopy. They also examined whether polymorphisms in TIM-1 can alter susceptibility to atopy.

The researchers identified a 6-amino-acid insertion at residue 157 (157insMTTTVP) and 2 single-amino-acid changes. To determine the effect of 157insMTTTVP on the occurrence of atopy, the team evaluated 375 individuals who were tested for atopy and prior HAV infection.

The research team found that HAV seropositivity protects against atopy. However, this protection only occurs in individuals with the 157insMTTTVP variant of TIM-1.

Prior to 1970, the seroprevalence of antibodies against HAV approached 100% in Western countries. Therefore infection with HAV may have protected many individuals against atopy.

However, reduction in family size and improved public health has caused anti-HAV seroprevalence to fall to between 25 and 30%, while the prevalence of atopic disease has doubled.

The interaction between HAV and TIM-1 genotype may contribute to the etiology of atopic diseases, and provide a mechanism to account for the hygiene hypothesis.

Dr Jennifer McIntire's team concluded, "Our finding…indicates that exposure to a specific pathogen may influence the expression of atopy".

"A declining prevalence of HAV infection could contribute to an increase in atopy by association with TIM-1".

"It will be necessary to determine whether HAV exposure must occur during childhood to have a protective effect".

Also, "Whether HAV can mitigate the severity of existing atopic disease, and whether HAV vaccination can reproduce the effects of natural HAV infection".

Nature 2003; 425: 576
13 October 2003

Go to top of page Email this page Email this page to a colleague

 23 February 2018 
Patients on antithrombotic agents undergoing emergency and elective endoscopy
 23 February 2018 
Heavy metals on a gluten-free diet
 23 February 2018 
MRI and NAFLD
 22 February 2018 
Outcomes with Crohn’s after infliximab withdrawal
 22 February 2018 
Elderly onset of IBD

 22 February 2018 
Autophagy enhancers
 21 February 2018 
Management of hemorrhoids in the USA
 21 February 2018 
Adalimumab and infliximab in biologic-naïve Crohn's
 21 February 2018 
Cystic fibrosis and colorectal cancer
 20 February 2018 
Complications and surveillance colonoscopies
 20 February 2018 
Treatment algorithm for polyp cancers
 20 February 2018 
Predictors of postoperative infection in Crohn's
 19 February 2018 
Screening colonoscopy in the right and left colon
 19 February 2018 
NAFLD prevalence in the USA
 19 February 2018 
Fructans in children with IBS

 16 February 2018 
Inflammatory bowel diseases are global diseases
 16 February 2018 
Undetected celiac in the elderly
 16 February 2018 
Fructans induce non-celiac gluten sensitivity
 15 February 2018 
NSAIDS and GI damage
 15 February 2018 
Oral direct-acting antiviral treatment for Hep C virus genotype 1
 15 February 2018 
Primary vs secondary surgery for the presence of lymph node metastasis
 14 February 2018 
Predicting adenoma detection rate
 14 February 2018 
Normal bowel frequency characterization in the USA 
 13 February 2018 
Personalising treatment options for IBS
 13 February 2018 
Prebiotics improve endothelial dysfunction
 13 February 2018 
Diagnostic criteria for a Rome IV functional gastrointestinal disorders
 12 February 2018 
Visceral hypersensitivity and functional GI disorders
 12 February 2018 
Depression and aggressive IBD
 12 February 2018 
Variability in interpretation of endoscopic findings impacts patient management
 09 February 2018 
Treatment of choice for anastomotic stricture in IBD
 09 February 2018 
PRO measurement information system 
 09 February 2018 
Overall disease severity indices for IBD
 08 February 2018 
Prediction of endoscopically active disease

 08 February 2018 
Steroid-refractory acute severe ulcerative colitis
 08 February 2018 
Decision aid used by IBD patients
 07 February 2018 
Ursodeoxycholic acid combined with bezafibrate for itching
 07 February 2018 
Change in microbiome in gastritis vs gastric carcinoma
 07 February 2018 
Colorectal cancer and primary sclerosing cholangitis-IBD
 06 February 2018 
Risk of death after liver transplantation
 06 February 2018 
Crohn’s disease vs refractory pouchitis
 06 February 2018 
Support for functional dyspepsia symptom diary
 05 February 2018 
Helicobacter spp influence on GI tract 
 05 February 2018 
No link found between severe reflux and all-cause mortality 
 05 February 2018 
Psychological distress in PPI non-responders
 02 February 2018 
Assessing psychosexual impact of IBD
 02 February 2018 
Decrease in overall mortality with cholera vaccination
 02 February 2018 
Diagnostic performance of fecal immunochemical tests
 01 February 2018 
Screening frequency with family histories of colorectal cancer
 01 February 2018 
IBD and sport participation
 01 February 2018 
Life with a stoma 
 31 January 2018 
Aprepitant and gastroparesis 
 31 January 2018 
Anesthesia risk in colonoscopy
 31 January 2018 
GED-0301 for Crohn's Disease
 30 January 2018 
Intestinal dysbiosis and allergic diseases in infants
 30 January 2018 
Fructans and IBS symptoms in children
 29 January 2018 
Dosing calculator for therapy optimization in IBD
 29 January 2018 
Glecaprevir–pibrentasvir for in HCV
 29 January 2018 
Food allergen injections in eosinophilic esophagitis
 29 January 2018 
Reliability of the IBD index
 26 January 2018 
Tofacitinib vs biological therapies for ulcerative colitis

Blackwell Publishing


GastroHep.com is a Blackwell Publishing registered trademark
© 2018 Wiley-Blackwell and GastroHep.com and contributors
Privacy Statement
Disclaimer
About Us