University College London, Institute of Neurology, London, UK.
Mult Scler. 2011 Nov;17(11):1333-40. doi: 10.1177/1352458511412654. Epub 2011 Jun 17.
Incorporation of routine clinical testing for neutralizing antibodies (NAbs) to interferon (IFN)-β has remained problematic. With increasing treatment choice for patients, routine NAb testing should be incorporated to aid therapeutic decisions.
We sought to improve interpretation of NAb results by combining the luciferase NAb assay (luciferase gene expression assay under control of interferon-stimulated response element) and in-vivo biomarker (myxovirus A protein, MxA) induction in patients with MS.
Blood samples (serum and PAXGene(®) for RNA) were obtained pre-injection and 12 hours post-injection of IFN-β from 144 subjects. Sera were tested for NAbs using the luciferase assay. MxA expression was quantified by real-time polymerase chain reaction (PCR).
26% of samples were NAb positive (titre > 20 NU). There was no difference in NAb titres in the pre- or post-dose sera (p = 0.643). MxA expression was inhibited in a dose-dependent fashion in NAb positive samples. Mean MxA level post-IFN-β: NAb negative 2330 (95% CI 1940-2719), NAb 20-99 NU 1533 (95% CI 741-2324), NAb 100-600 NU 832 (186-1478) and NAb > 600 NU 101 (95% CI 0-224). NAb titre and MxA level correlated strongly: MxA pre- (Spearman r = -0.72, p < 0.0001), MxA post- (Spearman r = -0.79, p < 0.0001) and MxA induction (Spearman r = -0.67, p = 0.0004).
A single, 12-hour post-injection sample should be used to test for NAbs using the luciferase assay and IFN-β bioactivity (MxA) in the clinical setting.
干扰素（IFN）-β中和抗体（NAb）的常规临床检测一直存在问题。随着患者治疗选择的增加，应常规进行 NAb 检测以辅助治疗决策。
我们试图通过联合使用荧光素酶 NAb 检测（干扰素刺激反应元件控制下的荧光素酶基因表达检测）和多发性硬化症患者体内生物标志物（流感 A 蛋白，MxA）诱导来改善 NAb 结果的解读。
从 144 名受试者中采集 IFN-β注射前和注射后 12 小时的血样（血清和 PAXGene（®）用于 RNA）。使用荧光素酶检测法检测血清中的 NAb。通过实时聚合酶链反应（PCR）定量 MxA 表达。
26%的样本 NAb 阳性（滴度>20 NU）。预剂量和后剂量血清中的 NAb 滴度没有差异（p=0.643）。在 NAb 阳性样本中，MxA 表达呈剂量依赖性抑制。IFN-β 后 MxA 平均水平：NAb 阴性 2330（95%CI 1940-2719），NAb 20-99 NU 1533（95%CI 741-2324），NAb 100-600 NU 832（186-1478）和 NAb>600 NU 101（95%CI 0-224）。NAb 滴度和 MxA 水平之间存在很强的相关性：MxA 预检测（Spearman r=-0.72，p<0.0001），MxA 后检测（Spearman r=-0.79，p<0.0001）和 MxA 诱导（Spearman r=-0.67，p=0.0004）。
在临床环境中，应使用单次注射后 12 小时的样本，通过荧光素酶检测法和 IFN-β 生物活性（MxA）检测 NAb。
