Pachner Andrew, Narayan Kavitha, Price Nicholson, Hurd Marie, Dail Donna
Department of Neurosciences, University of Medicine and Dentistry of New Jersey, New Jersey Medical School, Newark, New Jersey 08540, USA.
Mol Diagn. 2003;7(1):17-25. doi: 10.1007/BF03260016.
Interferon-beta (IFNbeta) has proven to be an important advance in the therapy of multiple sclerosis (MS), but optimal markers for bioactivity have not been identified. To accurately measure bioactivity in MS patients treated with IFNbeta, we developed and tested a real-time reverse transcriptase (RT)-PCR assay for gene expression of MxA, an IFNbeta-induced gene in the peripheral blood of patients treated with IFNbeta.
We compared IFNbeta-treated patients with MS to controls in expression of MxA relative to the house-keeping gene, GAPDH. 2'-5'oligoadenylate synthetase (OAS) gene expression was also tested by real-time RT-PCR on RNA from the same patient specimens. Anti-IFNbeta antibody was measured by ELISA and a cytopathic effect assay.
Seven of 54 patients were found to have complete loss of bioactivity. MxA expression correlated well with OAS expression. All patients with lost bioactivity had high levels of binding antibodies or neutralizing antibodies.
This is the first demonstration that a real-time RT-PCR assay can be used to monitor therapy with interferons. These data identify MxA mRNA as an excellent biomarker for INFbeta action on the IFN receptor, and clarify the relationship between anti-IFNbeta antibodies and bioactivity in patients with MS treated with IFNbeta.
干扰素-β（IFNβ）已被证明是多发性硬化症（MS）治疗的一项重要进展，但尚未确定生物活性的最佳标志物。为了准确测量接受IFNβ治疗的MS患者的生物活性，我们开发并测试了一种实时逆转录酶（RT）-PCR检测方法，用于检测MxA的基因表达，MxA是IFNβ诱导的基因，存在于接受IFNβ治疗患者的外周血中。
我们将接受IFNβ治疗的MS患者与对照组比较MxA相对于看家基因GAPDH的表达情况。还通过实时RT-PCR对来自相同患者标本的RNA检测2'-5'寡腺苷酸合成酶（OAS）基因表达。通过ELISA和细胞病变效应检测法测量抗IFNβ抗体。
54例患者中有7例被发现生物活性完全丧失。MxA表达与OAS表达密切相关。所有生物活性丧失的患者均有高水平的结合抗体或中和抗体。
这是首次证明实时RT-PCR检测法可用于监测干扰素治疗。这些数据确定MxA mRNA是IFNβ作用于IFN受体的优秀生物标志物，并阐明了接受IFNβ治疗的MS患者中抗IFNβ抗体与生物活性之间的关系。
