Variable Food-Specific IgG Antibody Levels in Healthy and Symptomatic Chinese Adults

Abstract

BackgroundThe presence of food-specific IgG antibodies in human serum may be useful for diagnosis of adverse food reactions. However, the clinical utility of tesing for such antibodies remains very controversial. The aim of this study was to evaluate the serum levels and population distribution of food-specific IgGs and their association with chronic symptoms in a large-scale Chinese population.Methodology/Principal FindingsA total of 21305 adult participants from different regions of China had 14 type of food-specific serum IgG antibodies that were measured by enzyme-linked immunosorbent assay. Amongthese, 5,394 participants were randomly chosen to complete follow-up questionnaire surveys on their dietary characteristics and chronic symptoms. The concentrations of food-specific IgGs against 14 foods ranged from a median (interquartile range) of 7.3 (3.8, 12.6) U/mL of pork-specfic IgG to 42.3 (28.8, 60.2) U/mL of crab-specific IgG. The concentration of food-specific IgGs was closely related to gender; after adjustment for region and age, women had higher concentrations of food-specific IgGs against all of the 14 foods except chicken (regression coefficient (95% CI): 0.01 (−0.003, 0.023); P = 0.129) and corn (0.002 (−0.013, 0.016); P = 0.825). Similar results were also found in the relationship of geographic region to the food-specific IgG concentrations for the 14 foods. Chronic symptoms were negatively associated with the concentrations of a few food-specific IgGs, and were positively associated with the concentrations of other food-specific IgGs.ConclusionsThe levels of food-specific IgGs were variable both in healthy and in symptomatic Chinese adults. These findings raise awareness that demographic factors, the type of food and specific chronic symptoms should be considered before food elimination treatment based on IgG testing in patients with chronic symptoms is used in clinical practice.

The Prevalence of Antibodies against Wheat and Milk Proteins in Blood Donors and Their Contribution to Neuroimmune Reactivities

“…Estimates for food sensitivities that are not IgE-mediated are more difficult to determine, since percentages may vary from one food antigen to another, and even from gender to gender and location to location [7,8]. For example, reaction to various wheat proteomes could be involved in three distinct conditions called wheat allergy, celiac disease (CD) and non-celiac gluten sensitivity (NCGS) [9,10,11].…”

Guidelines on the management of IgE-mediated food allergies

“…These methods have not been successfully validated either technically or clinically to justify their use. Tests that yield the measurement of data but resulting in a false interpretation: Immunoglobulin G (IgG) or IgG4 antibody determination and lymphocyte transformation tests with foods do not enable to distinguish between affected and healthy individuals [ 45 ] neither in food allergy or in food intolerance. Their lack of diagnostic specificity results frequently to positive findings in healthy individuals.…”

Is perceived intolerance to milk and wheat associated with the corresponding IgG and IgA food antibodies? A cross sectional study in subjects with morbid obesity and gastrointestinal symptoms

“…These aspects could perhaps explain the lack of a correlation between the intake of the offending foods and the corresponding food antibodies in this study. The significance of the amount consumed of particular foods in increasing the serum concentrations of the corresponding food antibodies seems however inconclusive [ 22 – 24 , 43 ].…”