Sivakumar P, Marples L, Breen R, Ahmed L
Division of Asthma, Allergy and Lung Biology.
School of Medicine, King's College London, Strand, London.
Int J Tuberc Lung Dis. 2017 Jun 1;21(6):697-701. doi: 10.5588/ijtld.16.0803.
Pleural fluid adenosine deaminase (pfADA) is not routinely measured in patients with undiagnosed pleural effusion due to limited evidence of its diagnostic utility in areas of low tuberculosis (TB) prevalence.
We conducted a retrospective consecutive case series analysis of all patients who underwent pfADA testing from 2009 to 2015 at a tertiary service pleural centre in south London. Using receiver operating characteristic (ROC) curve analysis, we identified the optimal threshold at which maximal sensitivity and specificity were achieved.
Of the 132 patients tested for pfADA, 27 had confirmed pleural TB and 105 did not, with median pfADA levels of respectively 63 IU/l (interquartile range [IQR] 47-88) and 12 IU/l (IQR 7.5-22.5). ROC curve analysis determined the optimal pfADA cut-off to be 30 IU/l, which had positive and negative predictive values of respectively 60.5% and 98.9%, 96.3% sensitivity (95%CI 0.892-1.000) and 83.8% specificity (95%CI 0.768-0.909). The calculated area under the ROC curve was 0.934 (95%CI 0.893-0.975).
A pfADA level <30 IU/l makes a diagnosis of TB highly unlikely in the South London population. Its high sensitivity and negative predictive values make pfADA a valuable screening test for excluding suspected pleural TB.
由于在结核病（TB）低流行地区，胸膜液腺苷脱氨酶（pfADA）诊断效用的证据有限，因此在未确诊胸腔积液患者中，通常不常规检测该指标。
我们对2009年至2015年在伦敦南部一家三级胸腔服务中心接受pfADA检测的所有患者进行了回顾性连续病例系列分析。使用受试者工作特征（ROC）曲线分析，我们确定了实现最大敏感性和特异性的最佳阈值。
在132例接受pfADA检测的患者中，27例确诊为胸膜结核，105例未确诊，pfADA水平中位数分别为63 IU/l（四分位间距[IQR]47 - 88）和12 IU/l（IQR 7.5 - 22.5）。ROC曲线分析确定最佳pfADA临界值为30 IU/l，其阳性预测值和阴性预测值分别为60.5%和98.9%，敏感性为96.3%（95%CI 0.892 - 1.000），特异性为83.8%（95%CI 0.768 - 0.909）。计算得到的ROC曲线下面积为0.934（95%CI 0.893 - 0.975）。
在伦敦南部人群中，pfADA水平<30 IU/l时，患结核病的可能性极小。其高敏感性和阴性预测值使pfADA成为排除疑似胸膜结核的有价值的筛查试验。
