Spezifische IgE-Werte gegen Aero- und Nahrungsmittelallergene im Vergleich: Dr. Fooke ALLERG-O-LIQ und Pharmacia CAP-System

Two in vitro assays for the detection of allergen-specific IgE (sIgE) were compared reestimating sera with sIgE to common inhalants (birch t3, timothy g6, mugwort w6, cat dander el, dog dander e5, housdust mite D. pter. dl) and food allergens (FA) (hen's egg fl, cow's milk f2, wheat flour f4, soy bean f14, hazelnut f17, apple f49). Quantitative values (kU/l) of both systems were associated to different degrees depending on the allergen: allergen/n t3/48, g6/47, w6/39, e1/40, e5/42, d1/39. Spearman's rho 0.95***, 0.9***, 0.82***, 0.9***, 0.82***, 0.85***, allergen/n f1/37 f2/38 f4/68 f14/52f17/40 f49/40. Spearman's rho 0.84***, 0.6***, 0.6***, 0.31*, 0.68***, 0.82***, *** p < 0.001; * p < 0.05. Values to inhalants (t3, g6, el, e5) were scattered moderately around an ideal regression line (diagonal between x-and y-axis). In contrast, sIgE-levels to FA (f2, f4, f14, fl7) showed stronger discrepancies between both systems. Similarly, different degrees of association and spreading, depending on the individual allergen, were found comparing semiquantitative classes (0 - 6) of both systems. Taken together, values of sIgE to inhalants detected by different in vitro methods are stronger associated than sIgE to FA; IgE-values to allergens with one dominant major allergen (i.e. t3, el) seem to be more concordant than complex allergen mixtures (i.e. dl); identical units (kU/l) can not garantee equivalent IgE results. The data presented do not allow estimates of the real IgE concentrations or judgement on superiority of one of the tests over the other. The study is restricted to compare both methods analytically, since the diagnostic concordance could not be calculated due to a lack of corresponding clinical data. Despite these limitations, comparative sIgE studies are necessary and helpful to define the concordance of IgE values detected by different immunoassays. They also set the basis for subsequent improvement of allergens used in test systems detecting specific IgE.