[Analysis of the effectiveness of cross-reactive carbohydrate antigen determinant antibody adsorbents in identifying allergen-specific IgE antibodies].

This study aimed to investigate the influence of anti-cross-reactive carbohydrate determinant IgE antibodies (anti-CCD IgE) on the detection of allergen-specific IgE (sIgE) antibodies, as well as the application value of anti-CCD IgE adsorbents in detecting allergen sIgE. In this cross-sectional study, a total of 2 636 test samples from patients who received treatment in West China Hospital of Sichuan University and tested allergen sIgE using the western blot method from October 2020 to May 2021 were analyzed. In these samples, 709 samples tested postive of allergen sIgE. 46 stochastic venous serum samples that tested positive in both sIgE and anti-CCD IgE and 1 serum sample that tested positive in sIgE but negative in anti-CCD IgE were collected. These samples were processed by anti-CCD IgE adsorbents, followed by allergen sIgE detection. The difference between the two detection results before and after adsorption was analyzed. The allergen test results showed that the positive rate of anti-CCD IgE in samples was 2.6% (69/2 636) during the period of sample collection. After treatment with anti-CCD IgE adsorbents, the top three allergen-sIgE of the positive rate changed from tree combination 2 (willow/poplar/elm), common ragweed and peanut to dust mite combination, cockroach and crab. The positive anti-CCD IgE results of 46 samples all turned negative and the total positive sIgE antibody dropped by 62.8%; the positive rate of sIgE antibodies with the class result ≥2 significantly decreased after treatment with anti-CCD IgE adsorbents, especially the positive rate of common ragweed dropped by 96.2%. The results of positive samples showed that multiple sIgE antibodies declined by different ranges, involving up to 11 antibodies with a maximum decline of 4 classes. Strongly positive sIgE antibodies (the class result ≥4) also had a high conversion rate of negative (25.0%-100%). The positive sIgE antibodies in about 60% of the samples decreased by more than 2, and the sIgE antibodies in 17.4% of the samples turned completely negative. There was no change in the allergen sIgE detection results of the sample with negative anti-CCD IgE after treatment. In conclusion, sIgE antibodies including targeting common ragweed, humulus, tree combination 2 (willow/poplar/elm), etc. are susceptible to false positives caused by anti-CCD IgE. Treatment of samples with anti-CCD IgE adsorbents can significantly reduce the risk of false positives caused by anti-CCD IgE. It is necessary to pretreat samples that were anti-CCD IgE positive with anti-CCD IgE adsorbents, which can make laboratory results more accurate and provide a reference for diagnosis and prevention of allergic diseases.