Background: We have previously reported that IgA antigliadin antibodies (IgA-AGA) in the majority of healthy subjects are transient and do not indicate enteropathy, and also that an increased intake of gluten in the form of soda bread may be part of the explanation for this phenomenon.
Objective: The aim of the study was to determine whether gluten challenge with soda bread in subjects with transiently positive IgA-AGA could induce a significant titre of IgA-AGA.
Design: Food challenge study.
Methods: All subjects with positive IgA-AGA on screening at the time of the MONICA project in 1991 (T0) who developed negative serology at 3-year follow-up (T1) were invited to participate in a 'soda bread challenge' (1 loaf per day) for 1 month. Analysis of food intake was carried out prior to the challenge (T2) and compared to the analysis at the time of screening (T0). IgA-AGA and IgA antiendomysial antibodies (EMA) were checked pre- (T2) and post-challenge (T3).
Results: Ten subjects agreed to participate. Quantities of food ingested for the various categories did not differ significantly from T0 to T2. IgA-AGA titres did not differ significantly from T1 to T2 (20.2 versus 35.0, P=0.085). Mean IgA-AGA titres rose significantly between T2 and T3 (35.0 versus 40.3, P=0.005), although none of the subjects developed a significant titre of IgA-AGA. None of the subjects were positive for IgA-EMA.
Conclusions: Intake of soda bread does not appear to be an important explanation as to why subjects may have a transient rise in IgA-AGA titre since none of the subjects developed a significant titre of IgA-AGA.