Food IgG4 antibodies are elevated not only in children with wheat allergy but also in children with gastrointestinal diseases

Background: Food sIgG and sIgG(4) are highly individually versatile. We put a hypothesis that one of the responsible factors is the presence of gastrointestinal inflammatory diseases. The objectives were: 1. An analysis of wheat and rice sIgG and sIgG(4) in healthy children, children with IgE-mediated wheat allergy (WA), coeliac disease (CD) and Helicobacter pylori infection (HP). 2. Usability of wheat sIgG and sIgG(4) in the WA diagnostics. Methods: We compared 388 each wheat and rice sIgG and sIgG(4) in a group of 200 children: 50 WA (diagnosis, diet treatment, tolerance), 50 CD (diagnosis and remission), 50 HP and 50 healthy. SIgE, sIgG, sIgG(4) were determined with the FEIA method (Pharmacia CAP System). Results: In healthy children food sIgG were the lowest; no sIgG(4) were found. In the CD diagnosis group wheat and rice sIgG and rice sIgG(4) were the most common and their concentrations were the highest (p < .001, p < .05). Wheat sIgG(4) were the highest in WA children (diagnosis and tolerance) to fall during the elimination diet (p < .05). Wheat and rice sIgG remained the same in all allergy phases. Rice sIgG also did not differ in the class G(4). Conclusions: 1. Serum concentrations of wheat and rice sIgG and sIgG(4) are elevated in children with CD, HP and WA. 2. Sub-clinical incidence of some gastrointestinal inflammatory diseases may be responsible for high individual versatility of food sIgG and sIgG(4) concentrations in serum. 3. Wheat sIgG and sIgG(4) in children do not correlate with WA clinical picture.