Serological Tests in Gluten Sensitivity (Nonceliac Gluten Intolerance)

Goals: To characterize the serological pattern of gluten sensitivity (GS) and to compare it with that found in celiac disease. Background: GS has recently been identified as a new clinical entity included in the spectrum of gluten-related disorders, but it is still lacking of diagnostic markers. Study: Sera from 78 patients with GS and 80 patients with celiac disease were retrospectively assessed for immunoglobulin (Ig)G/IgA antigliadin antibodies (AGA), IgG deamidated gliadin peptide antibodies (DGP-AGA), IgA tissue transglutaminase antibodies (tTGA), and IgA endomysial antibodies (EmA). Results: IgG AGA were positive in 56.4% of GS patients and in 81.2% of celiac patients, with high antibody titers in both groups. IgA AGA were detected in 7.7% of GS patients and in 75% of celiac patients, showing lower enzyme-linked immunosorbent assay activities in GS than those found in celiac disease. Only 1 of the 78 patients with GS was positive for IgG DGP-AGA (detected in 88.7% of patients with celiac disease). IgA tTGA and IgA EmA were negative in all GS patients, whereas their positivity in celiac patients was 98.7% and 95%, respectively. Patients with GS displayed a variegated clinical picture with intestinal and extra-intestinal symptoms (abdominal pain, bloating, diarrhea, constipation, foggy mind, tiredness, eczema/skin rash, headache, joint/muscle pain, numbness of legs/arms, depression, and anemia) together with normal or mildly abnormal small intestinal mucosa. Conclusions: The serological pattern of GS is characterized by IgG AGA positivity in more than half of cases associated to IgA AGA in a few patients, but without EmA, tTGA, and DGP-AGA, which are the specific markers of celiac disease.