Paediatrics, Khoo Teck Puat-National University Children's Medical Institute, National University Health System, Singapore.
Clin Exp Allergy. 2015 Mar;45(3):687-97. doi: 10.1111/cea.12416.
Shellfish allergy in Singapore is highly prevalent, and shrimp allergy is the most common.
This study aims to evaluate the clinical characteristics and immunological phenotype of shellfish allergy in this population.
Patients with self-reported shellfish allergy were recruited from outpatient clinics of three large hospitals and from a population survey. Open oral food challenges (OFC) to glass prawn (Litopenaeus vannamei) and tiger prawn (Penaeus monodon) were carried out on all patients except for those who had a history of severe anaphylaxis. Skin prick tests (SPT) and specific IgE to crude and recombinant allergens were carried out to evaluate shrimp and dust mite sensitization. Immunoblots were used to assess IgE-binding proteins.
The 104 patients recruited were categorized into shellfish allergic (SA) when OFC was positive or had a history of severe anaphylaxis (n = 39), shellfish tolerant (ST) when OFC was negative (n = 27), and house dust mite positive controls (HDM(+) ) who were ST (n = 38). Oral symptoms (87.1%) were the predominant clinical manifestation. Positive challenge doses ranged from 2 to 80 g of cooked shrimp, with 25/52 patients reacting to either one or both shrimps challenged. The presence of specific IgE to shrimp either by SPT and/or ImmunoCAP(®) assay provided diagnostic test sensitivity of 82% and specificity of 22.2%. The inclusion of specific IgE to shrimp tropomyosin and IgE immunoblots with shrimp extracts did not improve the diagnostic proficiency substantially.
This study highlights the predominance of oral symptoms in shrimp allergy in tropical Asia and that a high provocation dose may be necessary to reveal shrimp allergy. Furthermore, specific IgE diagnostic tests and immunoblots were of limited use in this population.
在新加坡，贝类过敏的发病率很高，其中以虾类过敏最为常见。
本研究旨在评估该人群贝类过敏的临床特征和免疫表型。
从三家大医院的门诊和人群调查中招募了自我报告贝类过敏的患者。除了有严重过敏反应史的患者外，所有患者均进行开放性口服食物挑战（OFC），以测试玻璃虾（Litopenaeus vannamei）和虎虾（Penaeus monodon）。进行皮肤点刺试验（SPT）和粗制及重组过敏原特异性 IgE 检测，以评估虾和尘螨致敏情况。免疫印迹用于评估 IgE 结合蛋白。
104 例患者中，OFC 阳性或有严重过敏反应史的患者被归类为贝类过敏（SA）（n=39），OFC 阴性的患者被归类为贝类耐受（ST）（n=27），而 SPT 阳性的尘螨阳性对照（HDM(+)）患者被归类为 ST（n=38）。口腔症状（87.1%）是主要的临床表现。阳性挑战剂量范围为 2 至 80 克熟虾，25/52 例患者对一种或两种虾类均有反应。通过 SPT 和/或 ImmunoCAP(®)检测到虾特异性 IgE，其诊断试验的敏感性为 82%，特异性为 22.2%。包含虾肌球蛋白特异性 IgE 和虾免疫印迹与虾提取物并不能显著提高诊断能力。
本研究强调了热带亚洲虾类过敏以口腔症状为主，且可能需要高剂量激发来揭示虾类过敏。此外，在该人群中，特异性 IgE 诊断试验和免疫印迹的应用有限。
