①目的:确定牛奶特异性IgE ImmunoCAP检测与IgE抗体对牛奶过敏牛奶蛋白组份的反应是否一致。②方法:对30例(6-16岁)牛奶过敏患儿的血清【其中20例接受牛奶口服免疫治疗（MOIT）】进行Phadia ImmunoCAP检测，检测血清中牛奶（f 2)特异性IgE抗体，α-乳白蛋白-(ALA)、β-乳球蛋白-(BLG)、酪蛋白-(CAS)特异性IgE抗体水平。将血清抗牛奶IgE水平与血清抗α-乳白蛋白、β-乳球蛋白、酪蛋白IgE水平(kUa/L)的总和进行比较。偏差/不准确性的评估方法是偏离理想比率1.0的程度。所有IgE抗体水平>50 kUa/L的样本稀释后重新分析，以确保准确性。③结果:假设IgE抗ala - blg - cas的总和能准确反映或可能低估牛奶特异性IgE，MOIT前血清抗全奶IgE/抗ala - blg - cas IgE的总和比值为2.17-1.74 (n = 2;高估可能是由于IgE anti-BSA/乳铁蛋白缺失所致），1.04-0.90 (n = 3;相等）和0.77-0.42 (n = 25，低估)。在MOIT治疗的受试者中，抗牛奶IgE/IgE抗ala - blg - cas比值在MOIT治疗的一年内基本保持不变，尽管抗牛奶IgE的绝对水平出现波动，抗牛奶IgG显著增加。④结论:患者依赖性偏差可发生，只检测抗牛奶IgE可能低估IgE抗体与牛奶组份反应的实际水平高达2.4倍。虽然少数病人的牛奶特异性 IgE抗体水平和牛奶组份特异性IgE总和之间的一致性较好，但大部分是被低估了，原因可能是由于牛奶 ImmunoCAP中组份含量不足，这或许与临床有实质的相关性。
Agreement of Total vs. Component Milk-Specific IgE ImmunoCAP Measurements
RATIONALE: To determine the agreement between ImmunoCAP cow's milk-specific IgE measurements and IgE antibody responses to individual allergic milk protein components.
METHODS: Sera from 30 children (6-16 years) with cow's milk allergy, 20 of which received milk oral immunotherapy (MOIT), were analyzed for IgE anti-cow's milk-(F2), alpha-lactalbumin-(ALA), beta-lactoglobulin-(BLG) and casein-(CAS) by Phadia ImmunoCAP. IgE anti-cow's milk levels alone were compared to the sum of individual IgE anti-alpha-lactalbumin;beta-lactoglobulin;casein in kUa/L. Bias/inaccuracy was assessed by deviation from an ideal ratio of 1.0. All IgE antibody levels >50 kUa/L were re-analyzed at dilutions to insure accuracy.
RESULTS: Assuming the sum of IgE anti-ALA-BLG-CAS should accurately reflect, or possibly underestimate the total milk specific IgE, IgE anti-milk/summed IgE anti-ALA-BLG-CAS ratios for pre MOIT sera ranged from 2.17-1.74 (n = 2; over-estimate possibly due to missing IgE anti-BSA/lactoferrin), 1.04-0.90 (n = 3; equivalence) and 0.77-0.42 (n = 25, underestimate). In MOIT-treated subjects, IgE anti-milk/IgE anti-ALA-BLG-CAS ratios remained generally constant within each subject over a year of MOIT despite fluctuations in absolute IgE anti-milk levels and marked increases in IgG anti-milk.
CONCLUSIONS: Patient-dependent bias can occur in which IgE anti-milk measurements alone may underestimate the actual level of IgE antibody reactive with milk components by up to 2.4 fold. While the concordance between the levels of milk-specific IgE antibody and the summed individual IgE anti-milk components is good for a minority of milk allergic patients, there is a majority where underestimation, possibly due to limited molar excess of components on the milk ImmunoCAP, may be substantial and clinically relevant.
J. BogdanovicJ.M. Skripak A.W. Burks R.A. WoodR.G. Hamilton0