Association between Helicobacter pylori infection and food-specific immunoglobulin G in Southwest China

BACKGROUND Helicobacter pylori(H.pylori)has been found to be associated with extragastrointestinal diseases,possibly including adverse food reactions(such as food allergy or intolerance).However,there are few studies on H.pylori and food allergy or intolerance,and the results are inconsistent.Food-specific immunoglobulin(Ig)G has been revealed to be associated with food allergy or intolerance and can be used as a marker to explore the correlation between H.pylori infection and food allergy or intolerance.AIM To explore the relationship between H.pylori infection and food-specific IgG METHODS We retrospectively analyzed the physical examination data of 21822 subjects from February 2014 to December 2018 in this study.H.pylori infection was detected using the 13C urea breath test.Food-specific IgG of eggs,milk and wheat in serum was assessed.Subjects were grouped according to H.pylori positivity,and the positive rates of three kinds of food-specific IgG were compared between the two groups.Multivariable logistic regression analysis was performed to elucidate the association between H.pylori infection and food-specific IgG.RESULTS The total infection rate of H.pylori was 39.3%,and the total food-specific IgGpositive rates of eggs,milk and wheat were 25.2%,9.0%and 4.9%,respectively.The infection rate of H.pylori was higher in males than in females,while the positive rates of food-specific IgG were lower in males than in females.The positive rates of food-specific IgG decreased with age in both males and females.In the H.pylori-positive groups,the positive rates of food-specific IgG of eggs,milk and wheat were all lower than those in the H.pylori-negative groups.Multivariate logistic regression analysis revealed that H.pylori infection was negatively correlated with the food-specific IgG-positive rates of eggs,milk and wheat(odds ratio value of eggs 0.844-0.873,milk 0.741-0.751 and wheat 0.755-0.788,in different models).CONCLUSION H.pylori infection was found to be negatively associated with the food-specific IgG of eggs,milk and wheat in Southwest China.

Food allergy in gastroenterologic diseases:Review of literature

Food allergy is a common and increasing problem worldwide. The newly-found knowledge might provide novel experimental strategies, especially for laboratory diagnosis. Approximately 20% of the population alters their diet for a perceived adverse reaction to food, but the application of double-blind placebo-controlled oral food challenge, the ＂gold standard＂ for diagnosis of food allergy, shows that questionnaire-based studies overestimate the prevalence of food allergies. The clinical disorders determined by adverse reactions to food can be dassified on the basis of immunologic or nonimmunologic mechanisms and the organ system or systems affected. Diagnosis of food allergy is based on clinical history, skin prick tests, and laboratory tests to detect serum-food specific IgE, elimination diets and challenges. The primary therapy for food allergy is to avoid the responsible food. Antihistamines might partially relieve oral allergy syndrome and IgE-mediated skin symptoms, but they do not block systemic reactions. Systemic corticosteroids are generally effective in treating chronic IgE-mediated disorders. Epinephrine is the mainstay of treatment for anaphylaxis. Experimental therapies for IgE-mediated food allergy have been evaluated, such as humanized IgG anti-IgE antibodies and allergen specific immunotherapy.

Serological investigation of IgG and IgE antibodies against food antigens in patients with inflammatory bowel disease

BACKGROUND Food antigens have been shown to participate in the etiopathogenesis of inflammatory bowel disease (IBD),but their clinical value in IBD is still unclear.AIM To analyze the levels of specific immunoglobulin G (IgG) and E (IgE) antibodies against food antigens in IBD patients and to determine their clinical value in the pathogenesis of IBD.METHODS We performed a retrospective study based on patients who visited the First Affiliated Hospital of Nanjing Medical University between August 2016 and January 2018.A total of 137 IBD patients,including 40 patients with ulcerative colitis (UC) and 97 patients with Crohn’s disease (CD),and 50 healthy controls (HCs),were recruited.Serum food-specific IgG antibodies were detected by semiquantitative enzyme-linked immunosorbent assay,and serum food-specific IgE antibodies were measured by Western blot.The value of food-specific IgG antibodies was compared among different groups,and potent factors related to these antibodies were explored by binary logistic regression.RESULTS Food-specific IgG antibodies were detected in 57.5% of UC patients,in 90.72% of CD patients and in 42% of HCs.A significantly high prevalence and titer of foodspecific IgG antibodies were observed in CD patients compared to UC patients and HCs.The number of IgG-positive foods was greater in CD and UC patients than in HCs (CD vs HCs,P = 0.000;UC vs HCs,P = 0.029).The top five food antigens that caused positive specific IgG antibodies in CD patients were tomato (80.68%),corn (69.32%),egg (63.64%),rice (61.36%),and soybean (46.59%).The foods that caused positive specific IgG antibodies in UC patients were egg (60.87%),corn (47.83%),tomato (47.83%),rice (26.09%),and soybean (21.74%).Significantly higher levels of total food-specific IgG were detected in IBD patients treated with anti-TNFα therapy compared to patients receiving steroids and immunosuppressants (anti-TNFα vs steroids,P = 0.000;anti-TNFα vs immunosuppressants,P = 0.000;anti-TNFα vs steroids + immunosuppressants,P = 0.003).A decrease in food-specific IgG levels was detected in IBD patients after receiving anti-TNFα therapy (P = 0.007).Patients who smoked and CD patients were prone to developing serum food-specific IgG antibodies [Smoke: OR (95%CI): 17.6 (1.91-162.26),P = 0.011;CD patients: OR (95%CI): 12.48 (3.45-45.09),P = 0.000].There was no difference in the prevalence of food-specific IgE antibodies among CD patients (57.1%),UC patients (65.2%) and HCs (60%)(P = 0.831).CONCLUSION CD patients have a higher prevalence of food-specific IgG antibodies than UC patients and HCs.IBD patients are prone to rice,corn,tomato and soybean intolerance.Smoking may be a risk factor in the occurrence of food-specific IgG antibodies.Food-specific IgG antibodies may be a potential method in the diagnosis and management of food intolerance in IBD.