Role of A2 beta casein in milk-induced eosinophilic oesophagitis: novel in-vivo and in-vitro findings

We read with interest the article by Santacroce about personalised medicine in eosinophilic oesophagitis (EoE) and the identification of novel therapeutic targets.1 While dietary approaches are first-line treatment options for EoE, pathomechanisms are not well understood.2 Studies have shown that milk is the leading culprit category.3 4 It remains elusive if changes in dairy production are associated with EoE development. A dominant point mutation in beta casein occurred in ancestors to modern type cattle with a change from A2 milk (non-mutated) to A1/A2 milk (at least one point mutation, proline to histidine at position 67).5 Nothing is known about the allergenicity of standard versus A2 milk and its implications in EoE pathogenesis.