Scientific Study

BACKGROUND: Peanut allergy is one of the most severe food allergies. Whether breast feeding induces tolerance to peanuts or on the contrary, predisposes at risk-babies to occult allergic sensitization to peanuts is still a matter of discussion. We sought to investigate the transfer of the most potent peanut allergen Ara h 2 into human breast milk in a German breast milk study and to shed light on the time kinetics of Ara h 2 appearance. METHODS: We recruited 32 lactating, non-peanut allergic women, and collected breast milk samples at different time points after consumption of 100 g dry roasted peanuts. Breast milk samples were investigated for Ara h 2 with different immunological methods: by 2D immunoblotting with a patient's serum, by affinity enrichment using a monoclonal antibody against Ara h 2 followed by LC-MS/MS based detection and by a competitive inhibition ELISA for the detection of Ara h 2 and its digestion resistant peptides (DRP-Ara h 2). RESULTS: In a qualitative analysis Ara h 2 could be identified in a breast milk sample by 2D immunoblot by means of a patient's serum and furthermore by immunoaffinity enrichment followed by LC-MS/MS analysis. In a semi-quantitative analysis Ara h 2 and its digestion-resistant peptides were detected in the breast milk of 9 out of 32 subjects. Evidence suggests that Ara h 2 is excreted individually either rapidly (after 1 h, 2 h, 3 h or 4 h) or delayed (after 8 h or 12 h) and in different concentrations. CONCLUSIONS: Time and concentration of secreted Ara h 2 in breast milk appears to be individually regulated. The identification of Ara h 2 in breast milk is the prerequisite for the investigation of its sensitizing or tolerogenic properties. This article is protected by copyright. All rights reserved.