Published online Aug 26, 2019. doi: 10.12998/wjcc.v7.i16.2189
Peer-review started: April 12, 2019
First decision: May 16, 2019
Revised: June 21, 2019
Accepted: July 3, 2019
Article in press: July 3, 2019
Published online: August 26, 2019
Some food antigens have been considered to be involved in the processes of formation and development of human chronic intestinal inflammatory diseases. Food allergy and food intolerance are two types of adverse reactions to food. Food allergy is typically mediated by IgE antibodies. In contrast, food intolerance is mediated by IgG antibodies. However, this mechanism is disputable, as some studies found that food IgG and IgE antibodies can be expressed in healthy individuals. The purpose of this study was to analyze the levels of immunoglobulin G (IgG) and E (IgE) antibodies against food antigens in inflammatory bowel disease (IBD) patients and explore their clinical value in IBD pathogenesis.
IBD is a chronic relapsing inflammatory disease of the gastrointestinal tract, which includes ulcerative colitis (UC) and Crohn’s disease (CD). Increasing evidence indicates that IBD results from an abnormal mucosal immune system triggered by environmental factors. Of these factors, food antigens have been considered to involve in the processes of formation and development of IBD. Food allergy and food intolerance are two types of adverse reaction to food. Food allergy is typically mediated by IgE antibodies. In contrast, food intolerance is mediated by IgG antibodies. However, this mechanism is disputable, as some studies found that food IgG and IgE antibodies can be expressed in healthy individuals.
Food antigens have been suggested to participate in the etiopathogenesis of IBD. The advantages from removing certain foods from daily diet was focused on in recent studies. A number of IBD patients suffer from food intolerances, and they show an improvement of well-being by avoiding specific nutritive components. Previous studies have either researched on the potential involvement of various IgG/IgE subclasses in food intolerance/allergy. Although testing for the presence of food-specific IgG/IgEs has been regarded as a potential tool for the diagnosis of food intolerance/allergy, the accuracy and clinical utility of such testing remain unknown.
The purpose of this study was to analyze the levels of IgG and IgE antibodies against food antigens in IBD patients and explore the clinical value in the pathogenesis of IBD.
A total of 137 IBD patients, including 40 patients with UC and 97 patients with CD, and 50 healthy controls (HCs) were enrolled in this study. Blood samples were obtained from patients who visited the First Affiliated Hospital of Nanjing Medical University between August 2016 and January 2018. Serum IgG antibodies to 14 unique food antigens were assessed using enzyme-linked immunosorbent assay. IgE-specific antibodies to food allergens were examined by Western blot.
CD patients had a higher prevalence of food-specific IgG compared to UC patients. CD patients were more sensitive to tomato, corn, rice, soybean, wheat and codfish, while UC patients were more sensitive to tomato, corn and rice. Significantly higher levels of total food-specific IgG were detected in IBD patients treated with anti-TNFα therapy compared to patients receiving steroids or immunosuppressants. A decrease in food-specific IgG levels was detected in IBD patients after receiving anti-TNFα therapy. Smokers and CD patients were prone to developing serum food-specific IgG antibodies.
The prevalence of food-specific IgG is higher in CD patients than in UC patients and HCs. IBD patients may be prone to rice, corn, tomato and soybean intolerance.
Food-specific IgG antibodies may provide a clinical benefit for IBD patients via diet restriction. In the future, the role of food-specific IgG in food intolerance should be further investigated.