In wheat allergy, immunoglobulin E (IgE) is crosslinked by repeat sequences in gluten peptides (e.g., Ser-Gln-Gln-Gln-(Gln-)Pro-Pro-Phe), and non-gluten proteins induce the release of immune mediators such as histamine from basophils and mast cells.
In contrast, celiac disease, which affects ~1% of most populations, has characteristics of an autoimmune disorder. It can be identified based on serologic markers such as serum antibodies against tissue transglutaminase-2 (TG2), followed by intestinal biopsy confirmation and and its link to autoimmune co-morbidities.
There were reported cases of patients with gluten sensitivity in which allergic and autoimmune mechanisms could not be identified. They were collectively described as NCGS. The first description of NGCS goes back to the late seventies reporting 8 women with abdominal pain and diarrhea related to the ingestion of gluten, disappearing on GFD, but reappearing upon a gluten challenge.
Individuals who experience distress when eating gluten-containing products and then improve on a gluten-free diet (GFD) might have NCGS instead of celiac disease. Patients with NCGS develop adverse reactions when eating gluten-containing foods.
According to several authors, the NCGS prevalence is from 0.6% up to 13% of the general population. NCGS was reported more often among women, adults in the fourth decade of life and individuals coming from urban area.
The clinical presentation of NCGS is variable with multiple intestinal and extraintestinal symptoms occurring within hours, but in some patients only after several days upon the ingestion of gluten. Among intestinal symptoms the most frequent in NCGS are: bloating, abdominal discomfort and pain, diarrhea and flatulence.
The most common extra-intestinal symptoms were: tiredness, headache, foggy mind, musculoskeletal, skin manifestations and anxiety. Even less specific symptoms such as sleeping disturbances, mood swings, or hallucinations were reported after gluten ingestion.
Typically, symptoms appear soon or immediately after the ingestion of gluten-containing foods; they disappear/ameliorate after gluten withdrawal and reappear after gluten challenge.
Non-celiac gluten sensitivity (NCGS)
