Cantó Ester, Tintoré Mar, Villar Luisa Maria, Borrás Eva, Alvarez-Cermeño Jose Carlos, Chiva Cristina, Sabidó Eduard, Rovira Alex, Montalban Xavier, Comabella Manuel
Servei de Neurologia-Neuroimmunologia, Centre d'Esclerosi Múltiple de Catalunya (Cemcat), Institut de Recerca Vall d'Hebron (VHIR), Hospital Universitari Vall d'Hebron, Universitat Autònoma de Barcelona, Ps, Vall d'Hebron 119-129, Barcelona, 08035, Spain.
J Neuroinflammation. 2014 Nov 13;11:181. doi: 10.1186/s12974-014-0181-8.
In a previous proteomics study using pooled cerebrospinal fluid (CSF) samples, we proposed apolipoprotein AI, apolipoprotein AIV, vitronectin, plasminogen, semaphorin 7A, and ala-β-his-dipeptidase as candidate biomarkers associated with the conversion to clinically definite multiple sclerosis (CDMS) in patients with clinically isolated syndromes (CIS). Here, we aimed to validate these results in individual CSF samples using alternative techniques.
In a first replication study, levels of apolipoproteins AI and AIV, vitronectin, and plasminogen were measured by ELISA in CSF and serum of 56 CIS patients (29 patients who converted to CDMS (MS converters) and 27 patients who remained with CIS during follow-up (MS non-converters)) and 26 controls with other neurological disorders. Semaphorin 7A and ala-β-his-dipeptidase levels were determined by selected reaction monitoring (SRM) in CSF of 36 patients (18 MS converters, 18 non-converters) and 20 controls. In a second replication study, apolipoprotein AI levels were measured by ELISA in CSF of 74 CIS patients (47 MS converters, 27 non-converters) and 50 individual controls, and levels of semaphorin 7A and ala-beta-his-dipeptidase were determined by SRM in 49 patients (24 MS converters, 25 non-converters) and 22 controls.
CSF levels of apolipoprotein AI were increased (P = 0.043) and levels of semaphorin 7A and ala-β-his-dipeptidase decreased (P = 4.4 × 10(-10) and P = 0.033 respectively) in MS converters compared to non-converters. No significant differences were found in serum levels for apolipoproteins AI and AIV, vitronectin, and plasminogen. Findings with semaphorin 7A and ala-β-his-dipeptidase were also validated in the second replication study, and CSF levels for these two proteins were again decreased in MS converters versus non-converters (P = 1.2 × 10(-4) for semaphorin 7A; P = 3.7 × 10(-8) for ala-β-his-dipeptidase). Conversely, apolipoprotein AI findings were not replicated and CSF levels for this protein did not significantly differ between groups. Furthermore, CSF semaphorin 7A levels were negatively associated with the number of T2 lesions at baseline and one-year follow-up.
These results validate previous findings for semaphorin 7A and ala-β-his-dipeptidase, and suggest that these proteins play a role as CSF biomarkers associated with the conversion to CDMS in CIS patients.
在之前一项使用脑脊液（CSF）混合样本的蛋白质组学研究中，我们提出载脂蛋白AI、载脂蛋白AIV、玻连蛋白、纤溶酶原、信号素7A和丙氨酸-β-组氨酸二肽酶作为与临床孤立综合征（CIS）患者转变为临床确诊多发性硬化症（CDMS）相关的候选生物标志物。在此，我们旨在使用替代技术在个体CSF样本中验证这些结果。
在第一项重复研究中，通过酶联免疫吸附测定（ELISA）法检测了56例CIS患者（29例转变为CDMS的患者（MS转变者）和27例随访期间仍为CIS的患者（MS未转变者））以及26例患有其他神经系统疾病的对照者的CSF和血清中载脂蛋白AI和AIV、玻连蛋白及纤溶酶原的水平。通过选择反应监测（SRM）法测定了36例患者（18例MS转变者、18例未转变者）和20例对照者CSF中信号素7A和丙氨酸-β-组氨酸二肽酶的水平。在第二项重复研究中，通过ELISA法检测了74例CIS患者（47例MS转变者、27例未转变者）和5个个体对照者CSF中载脂蛋白AI的水平，通过SRM法测定了49例患者（24例MS转变者、25例未转变者）和22例对照者CSF中信号素7A和丙氨酸-β-组氨酸二肽酶的水平。
与未转变者相比，MS转变者CSF中载脂蛋白AI水平升高（P = 0.043），信号素7A和丙氨酸-β-组氨酸二肽酶水平降低（分别为P = 4.4×10⁻¹⁰和P = 0.033）。载脂蛋白AI和AIV、玻连蛋白及纤溶酶原的血清水平未发现显著差异。信号素7A和丙氨酸-β-组氨酸二肽酶的研究结果在第二项重复研究中也得到了验证，与未转变者相比，这两种蛋白的CSF水平在MS转变者中再次降低（信号素7A为P = 1.2×10⁻⁴；丙氨酸-β-组氨酸二肽酶为P = 3.7×10⁻⁸）。相反，载脂蛋白AI的研究结果未得到重复，该蛋白的CSF水平在各组之间无显著差异。此外，CSF信号素7A水平与基线及一年随访时的T2病变数量呈负相关。
这些结果验证了之前关于信号素7A和丙氨酸-β-组氨酸二肽酶的研究结果，并表明这些蛋白作为与CIS患者转变为CDMS相关的CSF生物标志物发挥作用。
