Shelly Shahar, Mills John R, Dubey Divyanshu, McKeon Andrew, Zekeridou Anastasia, Pittock Sean J, Harper C Michel, Naddaf Elie, Milone Margherita, Mandrekar Jay, Klein Christopher J
From the Departments of Neurology (S.S., D.D., A.M., A.Z., S.J.P., C.M.H., E.N., M.M., C.J.K.), Laboratory Medicine and Pathology (S.S., J.R.M., D.D., A.M., A.Z., S.J.P., C.J.K.), and Biomedical Statistics and Bioinformatics (J.M.), Mayo Clinic, Rochester MN.
Neurology. 2021 Jun 14;96(24):e2966-e2976. doi: 10.1212/WNL.0000000000012050.
To critically assess the clinical utility of striational antibodies (StrAbs) within paraneoplastic and myasthenia gravis (MG) serologic evaluations.
All Mayo Clinic patients tested for StrAbs from January 1, 2012, to December 31, 2018, utilizing Mayo's Unified Data Platform (UDP) were reviewed for neurologic diagnosis and cancer.
A total of 38,502 unique paraneoplastic evaluations and 1,899 patients with MG were tested. In paraneoplastic evaluations, the StrAbs positivity rate was higher in cancer vs without cancer (5% [321/6,775] vs 4% [1,154/31,727]; < 0.0001; odds ratio [OR] 1.35; confidence interval [CI] 1.19-1.53), but receiver operating characteristic (ROC) analysis indicated no diagnostic accuracy in cancer (area under the ROC curve [AUC] 0.505). No neurologic phenotype was significantly associated with StrAbs in the paraneoplastic group. Positivity was more common in all MG cancers compared to paraneoplastic cancers ( < 0.0001). In MG evaluations, the StrAbs positivity rate was higher in those with cancer vs without (46% [217/474] vs 26% [372/1,425]; < 0.0001; OR 2.39, CI 1.9-2.96), with ROC analysis indicating poor diagnostic accuracy for thymic cancer (AUC 0.634, recommended cutoff = 1:60, sensitivity = 56%, specificity = 71%), with worse accuracy for extrathymic cancers (AUC 0.543). In paraneoplastic or MG evaluations, the value of antibody positivity did not improve cancer predictions. Paraneoplastic evaluated patients with positive StrAbs were more likely to obtain CT ( = 0.0001), with cancer found in 3% (12/468).
Despite a statistically significant association with cancer, an expansive review of performance in clinical service demonstrates that StrAbs are neither specific nor sensitive in predicting malignancy or neurologic phenotypes. CT imaging is overutilized with positive StrAbs results. Removal of StrAbs from paraneoplastic or MG evaluations will improve the diagnostic characteristics of the current MG test.
This study provides Class II evidence that the presence of StrAbs does not accurately identify patients with malignancy or neurologic phenotypes.
严格评估横纹肌抗体（StrAbs）在副肿瘤性疾病和重症肌无力（MG）血清学评估中的临床应用价值。
回顾2012年1月1日至2018年12月31日期间，梅奥诊所利用梅奥统一数据平台（UDP）检测StrAbs的所有患者的神经诊断和癌症情况。
共对38,502例独特的副肿瘤性疾病评估和1,899例MG患者进行了检测。在副肿瘤性疾病评估中，患有癌症患者的StrAbs阳性率高于未患癌症患者（5%[321/6,775]对4%[1,154/31,727]；P<0.0001；优势比[OR]1.35；置信区间[CI]1.19 - 1.53），但受试者工作特征（ROC）分析表明其对癌症无诊断准确性（ROC曲线下面积[AUC]0.505）。在副肿瘤性疾病组中，无神经表型与StrAbs显著相关。与副肿瘤性癌症相比，StrAbs阳性在所有MG癌症中更常见（P<0.0001）。在MG评估中，患有癌症患者的StrAbs阳性率高于未患癌症患者（46%[217/474]对26%[372/1,425]；P<0.0001；OR 2.39，CI 1.9 - 2.96），ROC分析表明其对胸腺癌的诊断准确性较差（AUC 0.634，推荐临界值 = 1:60，敏感性 = 56%，特异性 = 71%），对胸腺外癌症的准确性更差（AUC 0.543）。在副肿瘤性疾病或MG评估中，抗体阳性值并未改善癌症预测。StrAbs阳性的副肿瘤性疾病评估患者更有可能接受CT检查（P = 0.0001），其中3%（12/468）发现患有癌症。
尽管与癌症存在统计学上的显著关联，但对临床服务中StrAbs表现的广泛回顾表明，StrAbs在预测恶性肿瘤或神经表型方面既不特异也不敏感。StrAbs结果呈阳性时CT成像被过度使用。从副肿瘤性疾病或MG评估中去除StrAbs将改善当前MG检测的诊断特征。
本研究提供了II类证据，即StrAbs的存在不能准确识别患有恶性肿瘤或神经表型的患者。
