[Evaluation of the analytical performance of the ImmunoCap 250 (Sweden Diagnostics)]

A new automate, ImmunoCap 250 has recently been released by Sweden Diagnostics for the determination of specific and total IgE. We have evaluated its analytical performances (intra- and inter-assay precision, linearity, recovery and sensibility) and compared the results obtained by Unicap 100 on 149 samples positive for 12 different allergens and 30 samples containing different concentrations of total IgE. Intra- and inter-assay precision are less than 10% excepted for the specific IgE of one allergen (i3, common wasp), but still in accordance with the NCCLS guidelines. The sensibility is 0.01 kU(A)/L for specific and 0.35 kU/L for total IgE. The method is linear up to 5000 kU/L for total and at least 80 kU(A)/L for specific IgE. The recovery test showed a recovery of the International standard WHO 75/502 between 85 and 115%, with a mean of 103%. The correlation coefficient between the ImmunoCap 250 and Unicap 100 is 0.9866 and 0.9984 for specific and total IgE respectively. ImmunoCap 250 is a good solution for laboratories that perform twenty to thirty thousand determinations.