Background Progressive multifocal leukoencephalopathy (PML) is caused by an opportunistic infection with JC polyoma virus (JCPyV) and mainly affects immunocompromised patients. It leads to pronounced demyelination of the central nervous system (CNS) resulting in severe disability or even death. Detection of JCPyV DNA in the cerebrospinal fluid (CSF) is usually accepted as proof for the diagnosis of PML. Routine CSF parameters, like CSF cell count, protein concentration, Qalbumin, or intrathecal immunoglobulin synthesis are mostly considered normal. However, this has not been investigated systematically. Methods We analyzed routine CSF parameters in a cohort of 108 PML patients that were treated at four different neurological centers in Germany. The patients exhibited different underlying conditions with natalizumab-treated multiple sclerosis (n = 54) and human immunodeficiency virus (HIV)-infection (n = 25) being the most frequent. The data were collected at the respective centers in accordance with local requirements and then jointly analyzed. The total PML cohort was compared with a control group of patients with normal pressure hydrocephalus (NPH) and idiopathic intracranial hypertension (IIH). Multiple sclerosis and HIV patients were additionally compared with their own non-PML control groups. Results The PML group showed an elevated cell count (p < 0.001) compared to the control group, however, this effect was mainly driven by HIV-PML patients. This subgroup also demonstrated a significantly higher proportion of patients with a disturbed blood-CSF-barrier function. Conclusions This comprehensive, retrospective study on CSF diagnostic analysis in PML patients provides insight into the CSF of those patients. It demonstrates that CSF composition in PML patients may be specific for the underlying condition that predisposes for the development of PML and thus data have to be interpreted in this context.

中文翻译：

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108例进行性多灶性白质脑病患者的脑脊液分析

背景 进行性多灶性白质脑病 (PML) 是由机会性感染 JC 多瘤病毒 (JCPyV) 引起的，主要影响免疫功能低下的患者。它会导致中枢神经系统 (CNS) 的明显脱髓鞘，从而导致严重的残疾甚至死亡。在脑脊液 (CSF) 中检测 JCPyV DNA 通常被认为是诊断 PML 的证据。常规 CSF 参数，如 CSF 细胞计数、蛋白质浓度、Qalbumin 或鞘内免疫球蛋白合成，通常被认为是正常的。然而，这还没有被系统地研究过。方法 我们分析了在德国四个不同神经中心接受治疗的 108 名 PML 患者队列的常规脑脊液参数。患者表现出不同的潜在疾病，其中那他珠单抗治疗的多发性硬化症（n = 54）和人类免疫缺陷病毒（HIV）感染（n = 25）最为常见。各中心根据当地要求收集数据，然后共同分析。将总 PML 队列与正常压力脑积水 (NPH) 和特发性颅内高压 (IIH) 患者的对照组进行比较。多发性硬化症和 HIV 患者还与他们自己的非 PML 对照组进行了比较。结果与对照组相比，PML 组的细胞计数升高（p < 0.001），然而，这种影响主要是由 HIV-PML 患者驱动的。该亚组还表明，血液-脑脊液屏障功能紊乱的患者比例显着更高。结论 这项关于 PML 患者 CSF 诊断分析的全面回顾性研究提供了对这些患者 CSF 的深入了解。它表明 PML 患者的脑脊液成分可能对易患 PML 的潜在病症具有特异性，因此必须在这种情况下解释数据。