Allergen diagnosis strategy: An experimental application of different methods in Guangzhou, Southern China

A study of allergen detection panel in Guangzhou, southern China based on real-world data from the past 7 years

This study aims to reduce the cost of allergen testing for Guangzhou, China by limiting the number of allergens for which patients are tested, and provide a testing panel to improve diagnostic and therapeutic efficiency. This retrospective study of real-world data from 2012 to 2019 included 39,570 patients with suspected allergies in Guangzhou, southern China. All the patients were tested for one or more of the following allergens serum specific immunoglobulin E (sIgE): Dermatophagoides pteronyssinus, Dermatophagoides farinae, cat dander, dog dander, Artemisia vulgaris, Aspergillus fumigatus, Alternaria alternata, Blattella germanica, egg whites, milk, wheat, peanuts, soybeans, Cancer pagurus, and Penaeus monodon by PhadiaCAP 1000. Totally, only the positive rates of allergens sIgE in D. farinae, D. pteronyssinus, milk, egg whites, B. germanica, C. pagurus, A. alternata, and P. monodon were > 10%, the other allergens were between 4-7%. Moreover, among the allergic diseases, dust mites exhibited the overall highest positive rate, followed by milk and B. germanica. In children, milk was the main allergen, whereas in adults, mites, cockroaches, shrimp, and crab allergens had higher positive rates. The optimal scale analysis shows that the multiple sensitization classification of patients can be divided into three categories: I D. farinae and D. pteronyssinus; II. C. pagurus, P. monodon, and B. germanica; III. Milk and egg whites. Generally, a panel including 4 allergens can detect > 90% of the potential allergy in this local population. In Guangzhou, southern China, D. farinae, milk, B. germanica, and A. alternata as a panel screening allergy for suspected allergic patients was suggested base on this study.

CCD Inhibition Test Can Improve the Accuracy of the Detection of Pollen and Seed Food Allergen-Specific IgE in Southern China

Objective

The presence of cross-reactive carbohydrate determinants (CCDs) may cause false-positive results in vitro allergen sIgE tests. In this paper, we focused on pollen sensitisation and its relationship with CCD in patients with respiratory allergic diseases in South China. A CCD inhibition test was conducted to assess whether patients were truly allergic to pollen or whether their sIgE was caused by a CCD cross-reaction, thus providing an important basis for clinical diagnosis and treatment.

Methods

Patients with known serologic pollen sensitization were selected, and sIgE of mugwort, tree mix 20 (willow/poplar/elm tree), common ragweed, Humulus scandens, peanut, soybean and CCD was detected via the EUROBlotMaster system. Thirteen CCD-sIgE negative patients and 33 CCD-positive patients were selected, and their serum samples were subjected to the CCD inhibition test.

Results

We found that 66.0% to 95.9% of patients sensitised to pollen and seed food allergens were co-sensitized to CCD. Additionally, 73.0% to 100% of the sIgE tests for pollen and seed food allergens turned negative after inhibition, mostly for allergens from Humulus scandens (100%, 15/15), followed by mugwort and peanut (85.2%, 23/27), ragweed (81.5%, 22/27), soybean (80.0%, 20/25), and tree pollen (73.0%, 19/26).

Conclusion

CCD causes false positives in the in vitro allergen sIgE tests of patients with respiratory allergic diseases in South China. Attention should be paid to the use of CCD inhibitors in diagnosing in vitro allergies because of their importance in diagnosing and treating local allergic diseases.