RYE FLOUR ALLERGENS ASSOCIATED WITH BAKERS ASTHMA - CORRELATION BETWEEN IN-VIVO AND IN-VITRO ACTIVITIES AND COMPARISON WITH THEIR WHEAT ANDBARLEY HOMOLOGS

Background A number of wheat and barley flour proteins that belong to the cereal alpha-amylase/trypsin inhibitor family have been identified as major allergens associated with baker's asthma. However, the aller genic role of this protein family had not been investigated in rye. Ob jective To study the allergenicity of five purified proteins from rye flour which belong to the same inhibitor family, as well as to compare their properties with those of their wheat and barley homologues. Met hods In vivo skin-prick tests were carried out in 21 patients with rad ioallergosorbent test (RAST) 2-3 to rye and allergic sensitization mai nly to this cereal flour. In addition, sera from all these patients we re used to assay the IgE binding capacity of dot blotted purified prot eins. Results Three of the rye proteins tested, namely Sec c 1, RDAI-1 and RDAI-3, provoked positive skin-prick tests in more than 50% of pa tients, although their in vitro reactivity was lower. Different reacti vities were found for the rye components compared with their wheat and barley homologues. Statistical analyses showed a significant correlat ion between the results of in vivo and in vitro tests for seven out of the nine purified proteins considered in this study. Conclusion Membe rs of the rye alpha-amylase inhibitor family are main allergens involv ed in allergic reactions to cereal flours. However, different allergen ic behaviours were found between homologous allergens from rye, barley , and wheat.