Supplementary Material for: Prevalence and Clinical Relevance of IgE Sensitization to Profilin in Childhood: A Multicenter Study

Background: Little is known about the prevalence and clinical relevance of hypersensitivity to the plant panallergen profilin in children. Objectives: The present study aimed to investigate prevalence, risk factors and clinical relevance of profilin sensitization in a large cohort of Italian children of different ages living in different geographic areas. Methods: Children with pollen allergy enrolled by 16 pediatric outpatient clinics sited in three main geographic areas of Italy were studied. SPT were carried out with commercial pollen extracts and a commercial purified date palm pollen profilin. IgE specific for allergenic pollen molecules, Phl p 12 (grass profilin) and Pru p 3 (peach lipid transfer protein) were tested by ImmunoCAP FEIA. Results: IgE to Phl p 12 (≥0.35 kU/l) was observed in 296 of the 1,271 participants (23%), including 17 of the 108 (16%) preschool children. Profilin SPT was positive (≥3 mm) in 320/1,271 (25%) participants. The two diagnostic methods were concordant in 1,151 (91%, p < 0.0001) cases. Phl p 12 IgE prevalence declined from northern to southern Italy and was directly associated with IgE to Phl p 1 and/or Phl p 5 and Ole e 1. Among children with IgE to Phl p 12, OAS was provoked by kiwi, melon, watermelon, banana, apricot and cucumber. Conclusions: Profilin sensitization is very frequent among pollen-allergic children, occurs at a very young age and contributes to the development of childhood OAS with a typical pattern of offending foods. Pediatricians should always consider IgE sensitization to profilin while examining pollen-allergic children, even if they are at preschool age.

研究背景：目前学界对儿童群体中植物泛变应原profilin（脯氨酸蛋白）超敏反应的流行率及其临床相关性尚缺乏充分认识。
研究目的：本研究旨在针对居住于意大利不同地理区域、不同年龄段的大型儿童队列，探讨profilin致敏的流行率、危险因素及临床相关性。
研究方法：本研究纳入了意大利三大地理区域的16家儿科门诊招募的花粉过敏患儿。采用商品化花粉提取物及商品化纯化海枣花粉profilin开展皮肤点刺试验（Skin Prick Test，SPT）；通过ImmunoCAP FEIA（荧光酶免疫分析法）检测变应原花粉分子Phl p 12（草花粉profilin）及Pru p 3（桃脂质转移蛋白）的特异性IgE水平。
研究结果：1271名受试者中，共296名（23%）检出Phl p 12特异性IgE（≥0.35 kU/l），其中108名学龄前儿童中有17名（16%）呈阳性。profilin皮肤点刺试验结果阳性（≥3mm）的受试者共320名，占总人数的25%（320/1271）。两种诊断方法的一致性达91%（1151/1271，p<0.0001）。Phl p 12特异性IgE的流行率从意大利北部到南部逐渐降低，且与Phl p 1和/或Phl p 5及Ole e 1的IgE水平呈正相关。在Phl p 12特异性IgE阳性的患儿中，猕猴桃、甜瓜、西瓜、香蕉、杏及黄瓜可诱发口腔过敏综合征（Oral Allergy Syndrome，OAS）。
研究结论：花粉过敏患儿中profilin致敏现象极为普遍，且可在极低龄时发生，其参与诱发儿童口腔过敏综合征，且具有典型的致敏食物谱。儿科医师在接诊花粉过敏患儿时，即便患儿为学龄前儿童，也应始终考虑其存在profilin特异性IgE致敏的可能。