Department of Neurology, School of Medicine, Second Affiliated Hospital, Zhejiang University, Hangzhou, China.
Harvard University School of Public Health, Boston, MA, United States.
Front Immunol. 2020 Aug 20;11:1799. doi: 10.3389/fimmu.2020.01799. eCollection 2020.
Early and accurate diagnosis of multiple sclerosis (MS) remains a clinical challenge. The main objective is to evaluate the diagnostic and prognostic value of the routinely performed immunoglobulin G (IgG) index for MS patients in the Asian population. A retrospective study was conducted among a cohort of clinically isolated syndrome (CIS) patients in China with known oligoclonal band (OCB) status and IgG index at baseline. We first evaluated the predictive value of IgG index for OCB status. Secondly, the diagnostic utility and prognostic value of IgG index alone were tested. Lastly, we incorporated IgG index into the 2017 McDonald criteria by replacing OCB with either "IgG index or OCB" (modified criteria 1), "IgG index and OCB" (modified criteria 2), or "IgG index" (modified criteria 3). The diagnostic utility of different criteria was calculated and compared. In a CIS cohort in China ( = 105), IgG index > 0.7 forecasted OCB positivity ( = 22.90, < 0.001). An elevated IgG index was highly prognostic of more clinical relapses [1-year adjusted odds ratio [OR] = 1.32, = 0.015; 2-years adjusted OR = 1.69, = 0.013] and Expanded Disability Status Scale worsening (1-year adjusted OR = 1.76, = 0.040; 2-years adjusted OR = 1.85, = 0.032). Under the 2017 McDonald criteria (Positive Likelihood Ratio = 1.54, Negative Likelihood Ratio = 0.56), an IgG index > 0.7 in CIS patients increased the likelihood of developing MS within 2 years, either when OCB status was unknown (Positive Likelihood Ratio = 2.11) or with OCB positivity (Positive Likelihood Ratio = 2.11) at baseline; An IgG index ≤ 0.7, along with a negative OCB, helped rule out the MS diagnosis (Negative Likelihood Ratio = 0.53). IgG index > 0.7 predicts OCB positivity at the initial attack of MS and is prognostic of early disease activity. IgG index serves as an easily-obtainable and accurate OCB surrogate for MS diagnosis in the Asian population.
早期、准确地诊断多发性硬化症（MS）仍然是一个临床挑战。本研究的主要目的是评估在亚洲人群中，常规进行的免疫球蛋白 G（IgG）指数对 MS 患者的诊断和预后价值。
本研究为回顾性研究，纳入了中国的临床孤立综合征（CIS）患者队列，这些患者基线时已知寡克隆带（OCB）状态和 IgG 指数。首先，我们评估了 IgG 指数对 OCB 状态的预测价值。其次，单独测试了 IgG 指数的诊断效用和预后价值。最后，我们通过用“IgG 指数或 OCB”（修正标准 1）、“IgG 指数和 OCB”（修正标准 2）或“IgG 指数”（修正标准 3）代替 OCB，将 IgG 指数纳入 2017 年 McDonald 标准。计算并比较了不同标准的诊断效用。在中国的 CIS 队列中（n=105），IgG 指数＞0.7 预测 OCB 阳性（优势比[OR] = 22.90， ＜0.001）。升高的 IgG 指数高度预示着更多的临床复发（1 年校正 OR = 1.32， = 0.015；2 年校正 OR = 1.69， = 0.013）和扩展残疾状况量表恶化（1 年校正 OR = 1.76， = 0.040；2 年校正 OR = 1.85， = 0.032）。在 2017 年 McDonald 标准下（阳性似然比=1.54，阴性似然比=0.56），CIS 患者 IgG 指数＞0.7，无论是在基线时 OCB 状态未知（阳性似然比=2.11）还是 OCB 阳性（阳性似然比=2.11），都增加了在 2 年内发展为 MS 的可能性；IgG 指数≤0.7 联合阴性 OCB 有助于排除 MS 诊断（阴性似然比=0.53）。
综上所述，IgG 指数可预测 MS 首发时的 OCB 阳性，且与疾病早期活动度相关。在亚洲人群中，IgG 指数是一种简单易得的、准确的 MS 替代 OCB 标志物，可用于 MS 的诊断。
