Specific IgG levels to wheat in wheat tolerant professional cyclists may depend on a homeostatic immune response to a high consumption of wheat

SUMMARY

Background. Implication of IgG antibodies to wheat has been alleged in gastrointestinal symptoms. Precise data on the specific IgG levels in healthy subjects are lacking. Our objectives are to compare levels of IgG antibodies to wheat protein fractions in healthy non atopic or atopic subjects, and in healthy professional cyclist subjects, taking into account the quantitative consumption of wheat. Methods. 24 control subjects and 26 professional cyclist subjects were selected. ELISA was performed to 2 wheat commercial solutions and to 3 wheat protein fractions. Results. No significant difference was observed between non atopic and atopic subjects. For wheat flour extract, physiological norm determined was 3.27 mg/L sIgG concentration ± 1.25 CI (95% confidence intervals)for the professional cyclists (vs 1.56 mg/L ± 0,91 CI in control subjects, p-value: 0.040). For gluten solution, physiological norm was 1.42 mg/L ± 0.60 CI (vs 0.50 ± 0,24 CI in control subjects, p-value: 0.010). Conclusion. Atopic and non atopic healthy adults have a similar level of sIgG to wheat. Increased levels of sIgG are observed correlatively with an excessive consumption, and could contribute to homeostasis of tolerance. Studies searching for a pathogenic role of sIgG in certain pathologies should take into account the quantitative consumption.