①之前的研究已经证实现有的商业化的芹菜提取物制剂在诊断芹菜过敏中灵敏度的不足。②我们对基于重组和纯化天然芹菜过敏原的特异性IgE检测与基于提取物的特异性IgE检测进行比较，评价前者的诊断性能，并研究交叉反应性碳水化合物决定簇特异性IgE的干扰及其生物活性。③24名对芹菜的双盲安慰剂对照食物挑战结果呈阳性的受试者，20例白桦花粉过敏而对芹菜耐受的特应性对照，20例非特应性受试者入选研究队列。通过免疫ImmunoCAP，研究了芹菜过敏原(rApi g1.01、rApi g4、nApi g5)、提取试剂(芹菜、桦树、艾蒿、梯牧草花粉)、桦树花粉过敏原(rBet v1、rBet v1)和交叉反应碳水化合物的IgE结合。根据嗜碱性介质释放度测定过敏原的生物活性。④ ImmunoCAP组分分析显著提高了检测芹菜特异性IgE的敏感性20%。38%的芹菜过敏患者对碳水化合物结构敏感，其对糖蛋白Api g5的敏感与游离的多聚糖之间存在极好的相关性。特应性对照的阳性结果主要由蛋白质过敏原引起，而碳水化合物表位的影响较小。过敏原诱导介质释放的能力以Bet v1 > Api g1 > Api g5的顺序下降，证实IgE对碳水化合物表位的生物活性较低。⑤与基于提取物的诊断相比，组份诊断灵敏度从67%提高到88%。对Api g5的敏感性是由其多糖分子引起的，但不影响诊断特异性。
Assessment of component-resolved in vitro diagnosis of celeriac allergy
Previous studies have demonstrated insufficient sensitivity of commercially available celeriac extract reagents in the diagnosis of celeriac allergy.
We sought to assess the diagnostic performance of specific IgE determination based on recombinant and purified natural celeriac allergens in comparison with an extract-based assay and to investigate interference by IgE to cross-reactive carbohydrate determinants and its biologic activity.
Twenty-four subjects with a positive double-blind, placebo-controlled food challenge result to celeriac; 20 atopic control subjects with birch pollen allergy who tolerated celeriac; and 20 nonatopic subjects were enrolled. IgE binding was investigated for celeriac allergens (rApi g 1.01, rApi g 4, and nApi g 5), extract reagents (celeriac, birch, mugwort, and timothy grass pollen), birch pollen allergens (rBet v 1 and rBet v 2), and cross-reactive carbohydrate determinants by means of ImmunoCAP analysis. Biologic activity of allergens was determined based on basophil mediator release.
Component-resolved ImmunoCAP analysis considerably increased the sensitivity to detect celeriac-specific IgE by 20%. Sensitization to carbohydrate structures was detected in 38% of patients with celeriac allergy, and there was an excellent correlation between sensitization to the glycoprotein Api g 5 and isolated glycan. Positive results among atopic control subjects were mainly caused by protein allergens, whereas the effect of carbohydrate epitopes was marginal. The ability of allergens to induce mediator release decreased in the order Bet v 1 > Api g 1 > Api g 5, confirming the low biologic activity of IgE to carbohydrate epitopes.
Component-resolved diagnosis allowed an increase in diagnostic sensitivity from 67% to 88% compared with extract-based diagnosis. Sensitization to Api g 5 was attributable to its glycan moieties but did not interfere with diagnostic specificity.
Kerstin BauermeisterMScaBarbara K.Ballmer-WeberMDbMerimaBublinPhDcPhilippFritscheMDbKay-Martin O.HanschmannMScaKarinHoffmann-SommergruberPhDcJonasLidholmPhDdChristinaOberhuberPhDeStefanieRandowaThomasHolzhauserPhDaStefanViethsPhDa