The alcohol-soluble fraction of wheat gluten (gliadins) induces in genetically susceptible individuals immunologically mediated celiac disease (CLD). However, gliadins and related cereal proteins are not unique foodstuff targets of CLD patients' immune system.
Non-gluten wheat alpha-amylase inhibitor 0.19 (AAI 0.19) has been found to be capable of activating human monocyte-derived dendritic cells and inducing pro-inflammatory status in intestinal mucosa of patients with celiac disease (CLD). The possible contribution of this reactivity in incomplete remission of CLD patients on a gluten-free diet (GFD) is matter of contention.
In an attempt to characterize the antigenicity of AAI 0.19 in patients with active CLD, patients on a GFD and healthy controls we developed ELISA employing wheat recombinant AAI 0.19. Using this test we revealed a significant (P<0.001) elevation of IgA anti-AAI 0.19 antibodies (Ab) in patients with active CLD (12 out of 30 patients were seropositive) but also in CLD patients on a GFD (15/46), in contrast to healthy controls (2/59).
Anti-AAI 0.19 IgG Ab levels were increased (P<0.001) only in patients with active CLD (14/30) in contrast to the controls. Interestingly, the levels of anti-AAI 0.19 IgG Ab were decreased in CLD patients on a GFD (P<0.001, 1/46) compared to the controls (1/59).
Notably, 20 out of 30 patients with active CLD were positive either for IgA or for IgG anti-AAI 0.19 Ab. Thus, the majority of CLD patients developed a robust IgA and IgG Ab response against AAI 0.19.
These findings may contribute to the broadening of the knowledge about CLD pathogenesis.