Carlsson M, Thorell L, Sjölander A, Larsson-Faria S
AstraZeneca R&D Mölndal, Mölndal, Sweden.
Scand J Immunol. 2015 Apr;81(4):240-8. doi: 10.1111/sji.12270.
The inter- and intra-individual variability and seasonal variation of IgE, and high (FcεRI)- and low-affinity (CD23) IgE receptor expression in blood of seasonal allergic rhinitis (SAR) subjects, is not well studied. Thirty-two otherwise healthy subjects with a history of SAR to birch pollen and a positive skin prick test to birch pollen were sampled three times out of the pollen season and three times during the pollen season. FcεRI and CD23 expressions were analysed using flow cytometry. Total IgE was analysed using ImmunoCAP(®) and free IgE was analysed with a novel customised research assay using an IgG-FcεRI-chimera protein coupled to ImmunoCAP as capture reagent, ImmunoCAP-specific IgE conjugate and ImmunoCAP IgE calibrators. The performance of the free IgE assay was compared well with the reference ImmunoCAP total IgE assay. The working range of the assay was 0.35-200 kU/l IgE. FcεRI expression on basophils and CD23 expression on B cells showed low intrasubject variability both in and out of the pollen season (<10% CV). There was a small seasonal difference with lower total IgE levels (120 versus 128 kU/l; P = 0.004) and FcεRI expression (283 versus 325 mean fluorescence intensity (MFI); P < 0.001) during the pollen season. IgE, FcεRI expression and CD23 expression fulfilled biomarker and assay requirements of variability, and allergen exposure affected the biomarkers only to a minor degree. The free IgE assay may be used for measurement of free IgE levels in patients after anti-IgE antibody treatment.
季节性变应性鼻炎（SAR）患者血液中免疫球蛋白E（IgE）的个体间和个体内变异性及季节性变化，以及高亲和力（FcεRI）和低亲和力（CD23）IgE受体表达情况，尚未得到充分研究。32名既往有桦树花粉致SAR病史且对桦树花粉皮肤点刺试验呈阳性的健康受试者，在花粉季节之外采样3次，在花粉季节采样3次。采用流式细胞术分析FcεRI和CD23表达。使用免疫化学发光法（ImmunoCAP®）分析总IgE，使用一种新型定制研究检测法分析游离IgE，该检测法使用与免疫化学发光法偶联的IgG-FcεRI嵌合蛋白作为捕获试剂、免疫化学发光法特异性IgE结合物和免疫化学发光法IgE校准品。游离IgE检测法的性能与参考免疫化学发光法总IgE检测法相比良好。该检测法的工作范围为0.35 - 200 kU/l IgE。嗜碱性粒细胞上的FcεRI表达和B细胞上的CD23表达在花粉季节内外的受试者内变异性均较低（变异系数<10%）。花粉季节期间总IgE水平（120对128 kU/l；P = 0.004）和FcεRI表达（平均荧光强度分别为283对325；P < 0.001）存在较小的季节性差异。IgE、FcεRI表达和CD23表达满足生物标志物和检测法的变异性要求，且变应原暴露对生物标志物的影响较小。游离IgE检测法可用于测量抗IgE抗体治疗后患者体内的游离IgE水平。
