电化学发光免疫法测定梅毒螺旋体抗体指数在神经梅毒诊断中的应用

Diagnostic value of Treponema pallidum antibody index detected by electrochemiluminescence immunoassay in neurosyphilis

目的探讨梅毒螺旋体(Treponema pallidum,Tp)特异性抗体指数对神经梅毒(neurosyphilis,NS)诊断及分期、分型的应用价值。方法选取2020年3月—2022年12月于四川大学华西医院诊断为NS的患者50例为实验组,另选取同期非NS的梅毒患者50例为对照组,收集患者脑脊液/血清样本对和临床资料。应用美国临床实验室标准化协会(CLSI)EP06-Ed2文件评估电化学发光免疫法检测Tp特异性抗体的线性范围,并计算纳入样本的抗体指数。使用相关系数评价Tp抗体指数、IgG指数、IgG合成率、白蛋白商与其他临床指标的相关性,运用受试者工作特征(ROC)曲线比较上述指标对NS的诊断效能。结果所有血清和脑脊液样本的线性偏差均在允许线性偏差内,线性验证通过。与非NS组相比,Tp抗体指数在NS组中显著升高(P<0.05),但在不同分型、不同严重程度和是否接受治疗的NS组间,其差异无统计学意义(P>0.05)。Tp抗体指数、IgG指数、IgG合成率与血清Tp抗体、脑脊液Tp抗体、微量蛋白、有核细胞计数均呈正相关关系(P<0.05)。以14.99作为NS诊断的临界值,Tp抗体指数的诊断敏感度为74.0%(95%CI:60.5%~84.1%),特异度可达94.0%(95%CI:83.8%~98.4%),ROC曲线下面积为0.897,高于白蛋白商、IgG指数和IgG合成率的曲线下面积。结论本研究发现Tp抗体指数在NS患者中显著升高,具有较好的诊断敏感度和特异度,可为NS的诊断提供参考。

Objective To evaluate the value of Treponema pallidum(Tp)-specific antibody index in the diagnosis,staging,and typing of neurosyphilis(NS).Methods Fifty patients diagnosed with NS at the West China Hospital of Sichuan University from March 2020 to December 2022 were recruited as the experimental group,and 50 non-NS syphilis patients were enrolled during the same period as the control group.Cerebrospinal fluid(CSF)and matched serum samples along with clinical data were collected.Clinical and Laboratory Standards Institute(CLSI)EP06-Ed2 file was used to analyze the linear range of electrochemiluminescence immunoassay for Tp-specific antibody detection,and the Tp antibody index was calculate for all subjects.The correlation of Tp antibody index,IgG index,IgG synthesis rate,and albumin quotient with other clinical indicators was evaluated by the coefficient of correlation,and the diagnostic efficacy of these indicators in NS was analyzed using the receiver operating characteristic(ROC)curve.Results All the deviations from linearity of electrochemiluminescence immunoassay for detecting Tp antibodies in serum and CSF samples were within the allowable deviation from linearity.Compared with the non-NS group,the NS group showed a significant increase in the Tp antibody index(P<0.05),with no significant differences observed among the groups of different subtypes,severity,or receiving treatment or not(P>0.05).Tp antibody index,IgG index,and IgG synthesis rate were positively correlated with serum Tp antibody,CSF Tp antibody,trace protein,and nucleated cell count(P<0.05).Taking 14.99 as the cut-off value for NS diagnosis,the diagnostic sensitivity of Tp antibody index was 74.0%(95%CI:60.5%-84.1%),and the specificity was 94.0%(95%CI:83.8%-98.4%),with the area under the ROC curve of 0.897,which was larger than that of albumin quotient,IgG index,and IgG synthesis rate.Conclusions This study finds a significant increase in the Tp antibody index in NS patients with good diagnostic sensitivity and specificity,providing reference for the diagnosis of NS.