da Silva Diana Margarida Gonçalves Solha Pereira, Vieira Teresa Maria Silva, Pereira Ana Maria Alves, de Sousa Moreira André Miguel Afonso, Delgado José Luís Dias
Serviço de Imunoalergologia, Centro Hospitalar São João, Porto, Portugal ; Laboratory of Immunology, Basic and Clinical Immunology Unit, Faculty of Medicine, Porto University, Porto, Portugal.
Unidade de Imunoalergologia, Unidade Local de Saúde do Alto Minho, Viana Do Castelo, Portugal.
Clin Transl Allergy. 2016 Dec 22;6:46. doi: 10.1186/s13601-016-0136-5. eCollection 2016.
Challenge tests for food-dependent exercise-induced anaphylaxis (FDEIA) carry some risk and have a high rate of false negatives. Our aim was to explore the usefulness of an in vitro immunodepletion assay and an allergen microarray test in the identification of IgE-mediated cross-reactive food allergens in patients with suspected FDEIA or food-dependent exercise-induced urticaria and panallergen sensitization.
Three patients with a history of food dependent exercise induced urticaria/anaphylaxis and food panallergen sensitization in whom a food-exercise challenge was not feasible were selected: a 25-year-old man with cholinergic urticaria who experienced generalized urticaria and angioedema during a soccer match after drinking a peach-based soft drink; a 19-year-old woman with allergic rhinitis and controlled asthma who experienced anaphylactic shock while playing soccer, having eaten walnuts in the previous 90 min; and a 57-year-old man with baker's asthma who experienced four episodes of anaphylaxis during exercise after ingesting wheat-containing food. All individuals underwent a diagnostic work-up with skin prick tests, specific IgE (sIgE) and ImmunoCAP ISAC test. For the in vitro immunodepletion procedure, patients' serum was pre-incubated with the suspected native allergen (peach, walnut, or wheat) in solid phase (ImmunoCAP). The eluted serum, containing unbound IgE, was collected and samples were re-tested using Immunocap ISAC 112 and compared with baseline results.
All individuals were sensitized to lipid transfer proteins. The first patient was sensitized to Pru p 3, Cor a 8, Jug r 3, and Ara h 9; after pre-incubation with peach there was 100% depletion of sIgE to all components. The second patient was sensitized to Pru p 3, Cor a 8, Jug r 3, and Ara h 9; immunodepletion with walnut depleted sIgE to Ara h 9 by 67%, Pru p 3 and Pla a 3 (60%), Art v 3 (75%), Jug r 3 (88%), and Cor a 8 (100%). The third patient was sensitized to Pru p 3, Jug r 3, Ara h 9, and Tri a 14; immunodepletion with wheat depleted Tri a 14 only (100%).
In vitro immunodepletion might be a useful diagnostic tool in food dependent exercise induced urticaria/anaphylaxis with panallergen sensitization, particularly for identifying the culprit allergen and guiding dietary elimination recommendations.
食物依赖运动诱发过敏反应（FDEIA）的激发试验存在一定风险且假阴性率高。我们的目的是探讨体外免疫清除试验和过敏原微阵列检测在识别疑似FDEIA或食物依赖运动诱发荨麻疹及泛过敏原致敏患者中IgE介导的交叉反应性食物过敏原方面的实用性。
选择3例有食物依赖运动诱发荨麻疹/过敏反应病史且对食物泛过敏原致敏、无法进行食物 - 运动激发试验的患者：1例25岁患有胆碱能性荨麻疹的男性，在饮用桃味软饮料后踢足球时出现全身性荨麻疹和血管性水肿；1例19岁患有过敏性鼻炎且哮喘得到控制的女性，在踢足球前90分钟吃了核桃，踢球时发生过敏性休克；1例57岁患有面包师哮喘的男性，摄入含小麦食物后运动期间发生4次过敏反应。所有个体均接受了皮肤点刺试验、特异性IgE（sIgE）和免疫捕获过敏原芯片检测等诊断检查。对于体外免疫清除程序，将患者血清与固相（免疫捕获）中的疑似天然过敏原（桃、核桃或小麦）预孵育。收集洗脱后的血清，其中含有未结合的IgE，使用免疫捕获过敏原芯片112对样本重新检测，并与基线结果进行比较。
所有个体均对脂质转移蛋白致敏。首例患者对Pru p 3、Cor a 8、Jug r 3和Ara h 9致敏；用桃预孵育后，所有成分的sIgE均100%清除。第二例患者对Pru p 3、Cor a 8、Jug r 3和Ara h 9致敏；用核桃进行免疫清除后，Ara h 9的sIgE清除率为67%，Pru p 3和Pla a 3为60%，Art v 3为75%，Jug r 3为88%，Cor a 8为100%。第三例患者对Pru p 3、Jug r 3、Ara h 9和Tri a 14致敏；用小麦进行免疫清除后仅Tri a 14的sIgE被100%清除。
体外免疫清除可能是诊断食物依赖运动诱发荨麻疹/过敏反应伴泛过敏原致敏的有用工具，特别是在识别致病过敏原和指导饮食消除建议方面。
