Anaphylaxis caused by flaxseed

Methods and results Prick-prick carried out with flaxseed showed a strong positivity. Skin prick test to inhaled allergens were positive to mites, dog and cat danders, plain tree and grasses. Skin prick test to food allergens were positive to almond, hazelnut, peanut, chestnut, walnut, mustard, lentils, soybeans, rice, oat, corn and lupine. Total IgE was: 291 UI/ml. Specific IgE (CAP, ThermoFisher Scientific) to flaxseed was 2.68 kU peach 7.65 kU/L, peanut 2.01 kU / L , lettuce 0.92 kU / L , lupin 3.76 kU / L. Corn IgE 2.71 kU / L , Pru p3 7.62 kU / L , Cor a8 0.68 kU / L. ISAC, ImmunoCAP was positive to Fel d1, Phl p1, Der f1, Der f2, Der p1, Der p2, Pla a3, Ara h9, Cor a8, Jug r3, Pru p3 and Art v3. ISAC performed after inhibit patients’s serum (ISAC inhibition) with a complete flaxseed extract (f233:Linum usitatissium from ImmunoCAP, ThermoFisher Scientific) did not reduced the positivity to non-specific lipid transfer proteins (nsLTP). ISAC inhibition with a complete mite extract (d1: D. pteronyssinus from ImmunoCAP, ThermoFisher Scientific) reduces exclusively the signal of mites (Der f1, Der f2, Der p1, Der p2) in >83%.An immunoblot performed with flaxseed extracts (soluble and liposoluble), showed the presence of an IgE-binding band of about 18 kDa in the liposoluble fraction and a 20 kDa band in the soluble one.