胸部CT联合白介素-6检测对评估新型冠状病毒肺炎患者首诊病情的价值初探

Combined chest CT and IL-6 detection for the initial diagnosis of patients with COVID-19

目的探讨胸部CT评分和白介素-6(IL-6)指数联合评估新型冠状病毒肺炎(corona virus disease 2019, COVID-19)患者首诊病情分类的可行性。方法回顾性分析59例确诊COVID-19患者(COVID-19普通型患者29例,重型患者30例)病历资料,对胸部CT影像特征进行半定量评分并测定IL-6数值,采用spearman相关性分析比较COVID-19普通型及重型组患者IL-6指数和CT评分的相关性,应用logistic回归方法建模并绘制受试者工作特性曲线(ROC曲线),计算COVID-19重型患者的IL-6指数、CT评分最佳截断值(cut-off值)、敏感性及特异性,评估单项及联合IL-6指数、CT评分的诊断效能。结果 COVID-19普通型患者中9例IL-6指数正常;20例IL-6指数异常,数值范围为7.6~37.1 pg/ml,均值为(20.07±9.79)pg/ml,CT评分为5~12分,均值为(8.85±1.71)分。30例COVID-19重型患者IL-6指数异常,数值为58.53(38.33~100.30)pg/ml,CT评分为8~16分,均值为(13.00±2.61)分。COVID-19重型患者的IL-6指数及CT评分均高于普通型IL-6指数异常组,差异有统计学意义,P<0.01。COVID-19重型患者组和普通型IL-6指数异常患者组的IL-6指数与CT评分呈正相关(r分别为0.658,0.397,P均<0.05)。ROC曲线显示,联合采用IL-6指数及CT评分诊断COVID-19重型患者的最佳截断值分别为33.9 pg/ml、11分,敏感性为96.70%,特异性为89.70%,其诊断效能高于单独采用CT评分或IL-6指数。结论 COVID-19普通型及重型患者首诊胸部CT表现具有特征的影像改变,CT联合IL-6指数能有效提高COVID-19患者首诊病情判断的准确性。

Objective To explore the feasibility of evaluation of patients with COVID-19 using combined chest CT presentations and interleukin-6(IL-6) levels for classification after initial diagnosis. Methods A retrospective analysis of medical records of 59 confirmed cases of COVID-19(moderate and severe) was conducted using the semi-quantitative scoring of chest CT presentation and the blood IL-6 count.The Spearman correlation was used to compare the association between the IL-6 counts and the CT scores in the moderate group with IL abnormality and in the severity group.By evaluating IL-6 count, CT scores and combined IL-6 count + CT scores, the area under curve(AUC) and the 95% confidence interval of the receiver operator characteristic(ROC) curve and logistic regression analysis were computed to predict the probability of the severe COVID-19 and to calculate the sensitivity and specificity. Results Among moderate patients, 9 showed normal IL-6 counts while 20 with abnormal values.The range of the IL-6 counts was 7.6-37.1 pg/ml with a mean of (20.07±9.79)pg/ml.The chest CT images were characterized by the domination of glass shadow of the lungs with or without consolidation.The CT scores were from 5 to 12 points with a mean of(8.85±1.71)points.For severe patients,30 demonstrated abnormal IL-6 counts.The range was(38.33-100.3)pg/ml and the mean was 58.53 pg/ml.From chest CT images,multiple presentations of both lungs could be seen.The range of CT scores was from 8 to 16 points with a mean of(13.00±2.61)points.The IL-6 counts [58.53(38.33-100.3)pg/ml]and CT scores[(13.00±2.61)points]of the severe patients were both significantly higher than that of the moderate patients.Within the group of severe patients,the IL-6 counts were positively correlated with the CT scores(r=0.658,P<0.05;r=0.397,P<0.05),whereas no correlation was found in the group of moderate patients.The results of ROC curve showed that the best cut-off values of IL-6 count and CT score were 33.9 pg/ml and 11 points,respectively,in the diagnosis for severe patients using the combination of the two measures.The sensitivity was 96.70% and the specificity was 89.70%,both of which were better than those when using IL-6 count or CT score alone. Conclusions The chest CT of moderate and severe COVID-19 patients after initial diagnosis exhibited distinct imaging features.Combining chest CT presentations and IL-6 levels is helpful for the classification of COVID-19 patients after initial diagnosis.