Research and Development Department, Bial-Arístegui, Bilbao, Spain.
Int Arch Allergy Immunol. 2010;152(4):319-26. doi: 10.1159/000288285. Epub 2010 Feb 26.
Russian thistle (Salsola kali) pollen is an important cause of pollinosis in areas where rainfall is not abundant. Our aim was to develop an ELISA for quantification of the major allergen of S. kali extracts, Sal k 1, and to assess the correlation of this allergen content with the allergenic activity of extracts.
Sal k 1 was purified by ion exchange and gel permeation chromatography and identified by mass spectrometry. Monoclonal antibody 4C11 was used for capture at 5 microg/ml and biotin-labeled specific antiserum at 0.25 microg/ml served for detection. The allergenic activity of the pollen extracts was measured by enzyme allergosorbent test inhibition.
Sal k 1 reacted to 85% of sera from 40 S. kali-allergic patients and was able to inhibit 92% of the IgE-binding capacity of patients' serum pool to the whole extract. The ELISA had a lineal range between 1.25 and 20 ng/ml of purified Sal k 1. The intra- and interassay coefficients of variation were lower than 5 and 10%, respectively. The assay was very sensitive since it had a detection limit of 0.08 ng/ml. No reactivity was found outside the Amaranthaceae family where only Kochia and Salicornia sp. gave significant reactivity. A good correlation (Spearman's rho = 0.92) was obtained between Sal k 1 content of different S. kali extracts and their IgE-binding activity.
The results proved the usefulness of the two-site sandwich ELISA for aeroallergen control and for the standardization of S. kali pollen extracts intended for clinical use.
俄罗斯蓟（Salsola kali）花粉是降雨量不丰富地区花粉过敏的一个重要原因。我们的目的是开发一种用于定量 S. kali 提取物主要过敏原 Sal k 1 的 ELISA，并评估该过敏原含量与提取物的变应原活性之间的相关性。
Sal k 1 通过离子交换和凝胶渗透色谱法进行纯化，并通过质谱法进行鉴定。使用单克隆抗体 4C11 以 5 μg/ml 进行捕获，生物素标记的特异性抗血清以 0.25 μg/ml 用于检测。花粉提取物的变应原活性通过酶变应原吸附试验抑制法进行测量。
Sal k 1 与 40 名 S. kali 过敏患者的 85%血清发生反应，并能够抑制患者血清池对全提取物 IgE 结合能力的 92%。ELISA 在纯化的 Sal k 1 1.25 至 20 ng/ml 之间具有线性范围。批内和批间变异系数均低于 5%和 10%。该测定非常灵敏，检测限为 0.08 ng/ml。在苋科以外的家族中未发现反应性，只有 Kochia 和 Salicornia sp. 有显著反应性。不同 S. kali 提取物的 Sal k 1 含量与其 IgE 结合活性之间存在良好的相关性（Spearman's rho = 0.92）。
结果证明了双位点夹心 ELISA 对于空气变应原控制和用于临床用途的 S. kali 花粉提取物的标准化非常有用。
