184 IgG Gluten-Related Disorders Panel

Gliadin is the alcohol-soluble fraction of gluten, comprising the prolamin component of wheat. IgG antibodies to gliadin represent a humoral response that can occur following ingestion and intestinal exposure. Unlike IgA anti-tissue transglutaminase or deamidated gliadin peptide antibodies, IgG-gliadin lacks specificity for coeliac disease and is frequently found in both symptomatic and asymptomatic individuals, reflecting immune recognition rather than pathognomonic autoimmunity.

IgG-gliadin has largely been supplanted in coeliac serology by more specific markers, yet it appears on expanded food-sensitivity panels as a proxy for gluten exposure and potential non-coeliac gluten sensitivity. Positive results indicate immunological contact with gliadin but do not diagnose coeliac disease, autoimmune enteropathy, or IgE-mediated allergy. They may correlate with patient-reported symptoms when gluten is consumed, although placebo-controlled challenge data remain the reference for establishing causality.

Wheat contains multiple protein fractions beyond gliadin — glutenins, albumins, and globulins — each capable of eliciting immune responses. IgG antibodies to whole-wheat extract capture a broader antigenic repertoire than gliadin alone, reflecting cumulative exposure to wheat proteins. These antibodies develop through the gut-associated lymphoid tissue and may persist for weeks to months after exposure.

IgG-wheat forms part of comprehensive food-sensitivity panels and may signal immune reactivity in patients who report symptoms with wheat ingestion but lack coeliac or IgE-mediated wheat allergy. It does not replace coeliac serology (IgA-tTG, EMA) or IgE-mediated allergy testing (specific IgE, skin prick), and its clinical utility remains contested. Some practitioners use it to guide empirical elimination trials, but reproducibility and symptom correlation require prospective validation.

Rye is a cereal grain containing secalins, the prolamin analogues of wheat gliadin. Cross-reactivity between rye, wheat, and barley prolamins is common due to shared epitopes, and IgG antibodies to rye often co-occur with IgG responses to other gluten-containing grains.

IgG-rye extends the panel's coverage of gluten-related grains and may be clinically relevant in patients consuming rye bread, crispbreads, or traditional European grain products. Its interpretation parallels that of IgG-gliadin — a marker of immune exposure rather than a diagnostic test for coeliac disease or true allergy.

Barley prolamins (hordeins) share sequence homology with wheat gliadins and rye secalins, and immune cross-reactivity is frequent. IgG antibodies to barley arise in individuals consuming barley in soups, malt beverages, or fermented foods.

IgG-barley completes the classical gluten-grain trio. It is interpreted alongside wheat, rye, and gliadin results to assess cumulative gluten-grain exposure. Isolated barley reactivity is uncommon, and clinical significance is enhanced when multiple grain antibodies are elevated together.

This panel tests IgG responses to 184 individual food antigens spanning grains, dairy, legumes, nuts, seeds, fruits, vegetables, meats, seafood, and spices. The rationale is that immune recognition of dietary antigens — measured as IgG binding — may contribute to low-grade inflammation, gastrointestinal symptoms, or systemic complaints in susceptible individuals. The mechanistic link remains debated: IgG to food is a normal consequence of oral tolerance and mucosal exposure, and elevated titres may reflect frequency of consumption rather than pathology.

Comprehensive IgG food panels are widely used in integrative and functional medicine to guide elimination diets. Critics note that IgG positivity does not equate to clinical intolerance and that double-blind placebo-controlled food challenges — the reference standard — often fail to reproduce symptoms attributed to IgG-positive foods. Proponents counter that subset analyses and clinical context improve predictive value. In practice, positive results are used to construct time-limited elimination–rechallenge protocols rather than to diagnose fixed food allergy.