Clinical evaluation of a new quantitative method for specific IgE antibodies

We studied the analytical and clinical efficiency of a "second generation" technique for the in vitro determination of specific IgE, the so-called CARLA system (Capture Assay Radim Liquid Allergen). Reproducibility studies demonstrated satisfactory intra- and inter-assay analytical imprecision. The linearity test gave good results, and no significant interference by non-specific total IgE was found. The diagnostic efficiency of the system for the five most representative aeroallergens (D1, Dermatophagoides pteronyssinus; E1, Cat's epithelium; G5, Lolium perenne; W19, Parietaria officinalis and W5, Arthemisia absinthium) was evaluated using the Receiver Operating Characteristic (ROC) analysis in eighty-nine patients with suspected inhalant allergies. For each aeroallergen the area under the ROC curve and the most efficient threshold were calculated. Satisfactory areas under the ROC curve were found for D1, G5, E1 and W19, while a lower diagnostic efficiency was observed for W5. The most efficient thresholds differed from one allergen to another, although the differences were not great.