Department of Medicine, Clinical Immunology and Allergy Unit, Karolinska Institute, Stockholm, Sweden.
Department of Clinical Immunology and Transfusion Medicine, Karolinska University Hospital, Stockholm, Sweden.
Allergy. 2009 Oct;64(10):1472-1477. doi: 10.1111/j.1398-9995.2009.02051.x. Epub 2009 Apr 14.
Some patients with allergic asthma treated with anti-IgE (Xolair) do not become symptom free. Better criteria for response assessment than allergy skin tests or IgE determination are needed. The impact of the size of the disease relevant allergen-specific IgE antibody fraction, i.e. the percentage of IgE antibody of total IgE, was evaluated in cat allergic patients treated with the recommended doses of Xolair. Results were measured as changes in basophil allergen threshold sensitivity (CD-sens).
In a double-blind placebo controlled trial 20 patients with a high (>3.8%) and 18 with a low (<1%) percentage of IgE antibodies to cat were given Xolair for 16 weeks and the change in CD-sens was compared to 11 and 10 patients, respectively, in each group receiving placebo.
The CD-sens dropped significantly in both the high (P < 0.001) and low (P < 0.001) group on Xolair but did not change significantly after placebo. For Xolair-treated patients, at the end of the trial there was a highly significant (P < 0.001) difference in CD-sens between the high group, where no patients, and the low group, where 13/18 patients, had become negative.
The currently recommended doses of Xolair very efficiently eliminate IgE antibodies if the IgE antibody fraction is <1% of total IgE but has not enough effect on allergen sensitivity if the fraction is >3-4%. Further studies will show if increased doses of Xolair would help also these patients, who seem to represent about 1/3 of the patient population.
一些接受抗 IgE（奥马珠单抗）治疗的过敏性哮喘患者并未完全无症状。需要更好的反应评估标准，而不仅仅是过敏皮肤试验或 IgE 测定。评估了在接受奥马珠单抗推荐剂量治疗的猫过敏患者中，疾病相关过敏原特异性 IgE 抗体分数（即 IgE 抗体占总 IgE 的百分比）的大小的影响。结果通过嗜碱性粒细胞过敏原阈值敏感性（CD-sens）的变化来测量。
在一项双盲安慰剂对照试验中，20 例高（>3.8%）和 18 例低（<1%）猫 IgE 抗体百分比的患者接受奥马珠单抗治疗 16 周，比较了两组分别接受安慰剂的患者的 CD-sens 变化。
高（P<0.001）和低（P<0.001）组的 CD-sens 在奥马珠单抗治疗下均显著下降，但安慰剂治疗后无明显变化。对于接受奥马珠单抗治疗的患者，在试验结束时，高组（无患者）和低组（18 例中有 13 例）的 CD-sens 有非常显著的差异（P<0.001），后者的 CD-sens 已经转为阴性。
如果 IgE 抗体分数<1%总 IgE，目前推荐的奥马珠单抗剂量非常有效地消除 IgE 抗体，但如果分数>3-4%，对过敏原敏感性的影响不大。进一步的研究将表明增加剂量的奥马珠单抗是否对这些患者也有帮助，这些患者似乎占患者人群的 1/3 左右。
