Inter-Laboratory Comparison of Multi-Allergen-Specific Immunoglobulin E Screening Assay Using Polycheck Allergy Diagnostic / 임상검사와정도관리

BACKGROUND: Currently there is no external proficiency testing program for allergen-specific immunoglobulin E assays (sIgE) in Korea. The aim of this study was to evaluate the accuracy of sIgE performed in different laboratories in Korea using Polycheck Allergy Diagnostic (Biocheck GmbH, Germany) or simply ‘Polycheck’ and to further perform an inter-laboratory comparison of sIgE. METHODS: Three inter-laboratory trials were undertaken from June 2016 to December 2017 at nine institutions. Serum samples obtained from three patients who had a history of positive Polycheck results were used in each trial. A total of 59 allergens were evaluated from the standard panel, inhalation panel, and food panel. The acceptable rates (%) of classes 0–6 of the results were calculated using three different criteria, including the consensus of 80% participants of the College of American Pathologists (CAP), the most frequent value (MFV), and the Overall Misclassification Index Score (OMIS). RESULTS: The proportion of laboratories that showed acceptable results for CAP criteria, MFV, and OMIS were around 93.0%–97.7%, 66.3%–76.0%, and 0.1–1.3, respectively, in each trial. Under-performing institutes showed consistently higher (49/68, 72.1%) or lower (19/68, 27.9%) than acceptable results for all criteria. CONCLUSIONS: This is the first study evaluating the inter-laboratory variation of sIgE in Korea using various criteria. It was found that the acceptable rate could be altered based on changes in these criteria. These findings might be useful for the inter-laboratory comparison of sIgE in Korea in the future as well.

Development and Performance Evaluation of External Quality Controls for Allergen-Specific Immunoglobulin E Tests

BACKGROUND: Many companies have developed different methods and products for allergen-specific immunoglobulin E (IgE) tests. Because there is no standardised reference method, external quality assessment (EQA) is important for allergen-specific IgE test to ensure the comparability and reliability of the results from different laboratories. We prepared specimens for EQA of allergen-specific IgE tests and evaluated their stability. METHODS: Four pooled sera with 24 selected allergen-specific IgE levels were prepared and stored at −80℃. The stability of allergen-specific IgE levels was assessed on days 1, 7, and 14 at −20℃, 2℃ to 8℃, and 20℃ to 25℃, and then after 3 months at −80℃. Mock proficiency tests were performed with the four sets of prepared external quality controls for six laboratories, using the commercial multiple allergen simultaneous test (MAST) methodology. RESULTS: About 150 specimens (650 µL each) for EQA were prepared; randomly selected specimens showed similar IgE levels for the 24 allergens (±1 class). The levels of allergen-specific IgE remained stable throughout the study period (P>0.05). Although mock survey results from six laboratories using four MAST assays revealed some variability with a difference (2–3 class), no consistent differences were observed through the allergens or MAST methods. Qualitative results from the mock survey showed 85.4% (cut-off of class 1) and 81.3% (cut-off of class 2) concordance with the results from ImmunoCAP (Phadia, Sweden). CONCLUSIONS: The pooled sera prepared for allergen-specific IgE tests might be adequate and useful for EQA.

Analysis on the allergens specific IgE in patients with allergic diseases / 国际检验医学杂志

Objective To explore the positive distribution characteristics of common allergen specific immunoglobulin E(slgE)in patients with suspected allergy in the Affiliated Zhongshan Hospital of Sun Yat-sen University.Methods Fluorescence enzyme linked immunosorbent assay was used to detect the serum sIgE antibody of 1 884 patients with suspected allergy diseases,including four kinds of inhalant allergens combinations (dust mites,mold,animal skin,pollen)and four kinds of food allergens combinations (seafood,cereals,meat,dairy products)from March to October 2014.The slgE expression situation of different allergen,different gender and age in allergic patients were compared.Results The slgE positive rates of dust mites,animal fur,mildew,pollen in in-haled allergens were 73.9%,8.5%,6.5%,4.0%.The positive rates of seafood,dairy products,cereals,meat in food allergens were 47.8%,31.5%,23.0%,8.5%.The slgE positive rate of patients with allergic diseases who were allergic to two kinds or more mixed allergens was up to 82.0%,and often allergic to dust mites and animal fur.The slgE positive rate of different gender had no significant difference (P >0.05).The slgE positive rate decreased as age increased.Conclusion Dust mites are the main inhalant al-lergens combination,seafood,dairy products and cereals are the main food allergens combinations.Patients with allergic disease are allergic mixed allergens.SlgE positive rate decreases with increasing age.