Department of Public Health and Infectious Diseases, "Sapienza" University, P.le Aldo Moro, 5, 00185 Rome, Italy; IRCSS San Raffaele Pisana, Microbiology of Chronic Neuro-degenerative Pathologies, Rome, Italy.
Department of Public Health and Infectious Diseases, "Sapienza" University, P.le Aldo Moro, 5, 00185 Rome, Italy.
Mult Scler Relat Disord. 2020 Jun;41:102008. doi: 10.1016/j.msard.2020.102008. Epub 2020 Feb 13.
The risk of progressive multifocal leukoencephalopathy (PML), a brain infection caused by John Cunningham virus (JCPyV), is the main limitation to the use of natalizumab, highly effective in the treatment of relapsing remitting multiple sclerosis (RRMS) patients. Establishing the PML risk against expected benefits represents an obligatory requirement of MS treatment algorithm. In order to achieve this goal, the aims of this study were to establish if JCPyV-DNA detection and non-coding control region (NCCR) arrangements could play a role of biomarkers, supporting anti-JCPyV antibodies measurement, actually the only parameter for PML risk stratification.
Thirty RRMS patients in treatment with natalizumab were enrolled. Urine and blood samples were collected according to this calendar: baseline (T0), 4 (T1), 8 (T2), 12 (T3), 16 (T4), 20 months (T5) after beginning of natalizumab therapy. After JCPyV DNA extraction, a specific quantitative-PCR (Q-PCR) and arrangements' analysis of NCCR and Viral Capsid Protein 1 (VP1) were carried out.
Q-PCR detected JCPyV DNA in urine and blood from baseline (T0) to 20 natalizumab infusions (T5), although JC viral load in urine was significantly higher compared to viremia, at all selected time points. A contextual analysis of the anti-JCPyV-antibodies versus JCPyV-DNA detection revealed that viral DNA preceded the antibodies' presence in the serum. During the first year of natalizumab treatment, sequences isolated from blood displayed an archetype JCPyV NCCR structure with the occurrence of point mutations, whereas after one year NCCR re-organizations were observed in plasma and PBMC with duplication of NF-1 binding site in box F, duplication of box C and partial or total deletion of box D. VP1 analysis showed the amino acid change mutation S269F in plasma and S267L in PBMC, involving the receptor-binding region of VP1. Phylogenetic analysis suggested a stability and a similarity across different isolates of the JCPyV VP1.
We highly recommend considering JCPyV-DNA detection and NCCR re-organizations as viral biomarkers in order to accurately identify JCPyV-infected patients with a specific humoral response not yet detectable and to identify NCCR arrangements correlated with the onset of neurovirulent variants.
进行性多灶性白质脑病（PML）是一种由约翰·坎宁安病毒（JCPyV）引起的脑部感染，其风险是限制使用那他珠单抗的主要因素。那他珠单抗在治疗复发缓解型多发性硬化症（RRMS）患者方面非常有效。确定 PML 的风险与预期益处之间的关系是 MS 治疗算法的强制性要求。为了实现这一目标，本研究的目的是确定 JCPyV-DNA 检测和非编码控制区（NCCR）结构是否可以作为支持抗 JCPyV 抗体测量的生物标志物，实际上这是 PML 风险分层的唯一参数。
本研究纳入了 30 名正在接受那他珠单抗治疗的 RRMS 患者。根据以下日历收集尿液和血液样本：基线（T0）、4（T1）、8（T2）、12（T3）、16（T4）和 20 个月（T5）。在提取 JCPyV DNA 后，进行了特定的定量 PCR（Q-PCR）和 NCCR 及病毒衣壳蛋白 1（VP1）排列分析。
Q-PCR 在基线（T0）至 20 次那他珠单抗输注（T5）期间检测到尿液和血液中的 JCPyV DNA，尽管在所有选定的时间点，尿液中的 JC 病毒载量明显高于病毒血症。抗 JCPyV 抗体与 JCPyV-DNA 检测的对比分析表明，病毒 DNA 先于血清中抗体的出现。在那他珠单抗治疗的第一年，从血液中分离出的序列显示出典型的 JCPyV NCCR 结构，伴有单点突变，而在一年后，在血浆和 PBMC 中观察到 NCCR 重排，NF-1 结合位点在框 F 中发生重复，框 C 重复，框 D 部分或完全缺失。VP1 分析显示，血浆中的 S269F 和 PBMC 中的 S267L 氨基酸变化突变，涉及 VP1 的受体结合区。系统发育分析表明，JCPyV VP1 的不同分离株具有稳定性和相似性。
我们强烈建议将 JCPyV-DNA 检测和 NCCR 重排作为病毒生物标志物，以准确识别具有尚未检测到的特定体液反应的 JCPyV 感染患者，并识别与神经毒变体出现相关的 NCCR 排列。
