Evaluation of a new semiquantitative immunodot assay for the screening of specific IgE.

The Immunodot CMG is a new, simple assay for the semiquantitative screening of specific IgE. It does not necessitate any particular equipment. It consists of two nitrocellulose strips on which either five indoor or five outdoor allergens are bound. In the present evaluation, 82 serum samples from allergic patients were tested with the first strip and 101 with the second. The results were compared with those obtained with the CAP System (Kabi Pharmacia). A version using undiluted serum and a short incubation time (short version) appeared to be more sensitive than a long version using serum diluted 1:5. In most cases, the results agreed with those of the CAP System. Discordant results were found in 2-9% of the cases according to the allergen, and were most often negative with Immunodot CMG and positive with the CAP System, indicating a slightly lower sensitivity for the new test. When compared to the CAP System, the Immunodot CMG showed a sensitivity of 84.5% and a specificity of 94%. Readings were found to be reproducible and easy to perform with the naked eye. Our results showed that the Immunodot CMG test is comparable to the CAP System, which is slightly more sensitive but requires much more elaborate and expensive equipment.