Anti-gliadin antibodies in breast milk from celiac mothers on a gluten-free diet

María Roca, Sabine Lisa Vriezinga, Paula Crespo-Escobar, Renata Auricchio, David Hervás, Gemma Castillejo, Maria Carmen Mena, Isabel Polanco, Riccardo Troncone, Maria Luisa Mearin, Carmen Ribes-Koninckx, The PREVENT CD Study Group

To analyze the presence of total IgA and anti-gliadin antibodies (AGA) in BM from CD mothers who follow a gluten-free diet (GFD) and from mothers on a normal gluten-containing diet (ND). 218 samples of mature milk were obtained at different months of lactation (1-6) from 83 mothers (2 or more samples per mother) from Italy (Naples), The Netherlands (Leiden) and Spain (Madrid, Valencia and Reus): 42 CD mothers on GFD for more than 2 years and 41 non-CD mothers on a ND. Whey samples were analyzed for AGA-IgA by an indirect homemade ELISA and for total IgA (g/L) by a commercial ELISA kit. AGA-IgA was detected in BM, both in mothers on a GFD and mothers on a ND. AGA-IgA levels in both groups of mothers, CD and non-CD, show the same trend towards decreasing slightly along the months of lactation (p = 0.91). A different trend is observed for total IgA levels, decreasing markedly in CD mothers from the first month of lactation onwards but remaining stable in non-CD mothers (p = 0.048). A statistically significant association was found between the means of total IgA and AGA-IgA (p < 0.001). AGA-IgA is present in BM from mothers on a ND as well as in BM from mothers who had been on a GFD for years. This reflects the existence of a long-lasting immunological memory independent of the mother's diet. If the presence of these antibodies has any role in promoting the acquisition of gluten tolerance in the infant, our study shows that children of CD mothers would be on equal conditions as children of non-CD mothers.