Centre d'Esclerosi Múltiple de Catalunya, CEM-Cat, Unitat de Neuroimmunologia Clínica, Hospital Universitari Vall d'Hebron (HUVH), Barcelona 08035, Spain.
Brain. 2010 Apr;133(Pt 4):1082-93. doi: 10.1093/brain/awq035. Epub 2010 Mar 17.
In most patients with multiple sclerosis, the disease initiates with a first attack or clinically isolated syndrome. At this phase, magnetic resonance imaging is an important predictor of conversion to multiple sclerosis. With the exception of oligoclonal bands, the role of other biomarkers in patients with clinically isolated syndrome is controversial. In the present study, we aimed to identify proteins associated with conversion to multiple sclerosis in patients with clinically isolated syndrome. We applied a mass spectrometry-based proteomic approach (isobaric labelling) to previously collected pooled cerebrospinal fluid samples from patients with clinically isolated syndrome, who subsequently converted to clinically definite multiple sclerosis (n=30) and patients who remained as having clinically isolated syndrome (n=30). Next, three of the most represented differentially expressed proteins, i.e. ceruloplasmin, vitamin D-binding protein and chitinase 3-like 1 were selected for validation in individual cerebrospinal fluid samples by enzyme-linked immunosorbent assay. Only chitinase 3-like 1 was validated and cerebrospinal fluid levels were increased in patients who converted to clinically definite multiple sclerosis compared with patients who continued as clinically isolated syndrome (P=0.00002) and controls (P=0.012). High cerebrospinal fluid levels of chitinase 3-like 1 significantly correlated with the number of gadolinium enhancing lesions and the number of T2 lesions observed in brain magnetic resonance imaging scans performed at baseline, and were associated with disability progression during follow-up and shorter time to clinically definite multiple sclerosis (log-rank P-value=0.003). Cerebrospinal fluid chitinase 3-like 1 levels were also measured in a second validation clinically isolated syndrome cohort and found to be increased in patients who converted to multiple sclerosis compared with patients who remained as having clinically isolated syndrome (P=0.018). Our results indicate that patients who will convert to clinically definite multiple sclerosis could be distinguished from those patients who will remain as clinically isolated syndrome by proteomic analysis of cerebrospinal fluid samples. Although protein levels are also increased in other disorders characterized by chronic inflammation, chitinase 3-like 1 may serve as a prognostic biomarker for conversion to multiple sclerosis and development of disability which may help to improve the understanding of the aetiopathogenesis in the early stages of multiple sclerosis.
在大多数多发性硬化症患者中，疾病始于首次发作或临床孤立综合征。在这个阶段，磁共振成像（MRI）是向多发性硬化症转化的重要预测指标。除了寡克隆带外，其他生物标志物在临床孤立综合征患者中的作用仍存在争议。本研究旨在鉴定与临床孤立综合征患者向多发性硬化症转化相关的蛋白。我们应用基于质谱的蛋白质组学方法（同位素标记）对之前收集的临床孤立综合征患者的脑脊液样本进行分析，这些患者随后转化为临床确诊的多发性硬化症（n=30），而另一些患者则仍为临床孤立综合征（n=30）。然后，选择三个最具代表性的差异表达蛋白（即铜蓝蛋白、维生素 D 结合蛋白和几丁质酶 3 样蛋白 1），通过酶联免疫吸附试验在个体脑脊液样本中进行验证。结果仅几丁质酶 3 样蛋白 1得到验证，与继续为临床孤立综合征的患者和对照组相比，向临床确诊的多发性硬化症转化的患者的脑脊液水平升高（P=0.00002 和 P=0.012）。高水平的脑脊液几丁质酶 3 样蛋白 1与基线脑 MRI 扫描中观察到的钆增强病变和 T2 病变的数量显著相关，与随访期间的残疾进展和向临床确诊的多发性硬化症转化的时间较短相关（对数秩检验 P 值=0.003）。我们还在第二个验证性临床孤立综合征队列中测量了脑脊液几丁质酶 3 样蛋白 1 的水平，发现与继续为临床孤立综合征的患者相比，向多发性硬化症转化的患者的脑脊液水平升高（P=0.018）。我们的研究结果表明，通过对脑脊液样本进行蛋白质组学分析，可以将即将转化为临床确诊的多发性硬化症的患者与将继续保持为临床孤立综合征的患者区分开来。虽然其他以慢性炎症为特征的疾病也会增加蛋白水平，但几丁质酶 3 样蛋白 1 可能作为多发性硬化症转化和残疾发展的预后生物标志物，有助于深入了解多发性硬化症的发病机制。
