结核性胸腔积液（Tuberculous pleural effusion，TPE）和恶性胸腔积液（Malignant pleural effusion，MPE）可能偶尔呈现相似的细胞学和生化图像，包括腺苷脱氨酶（adenosine deaminase，ADA）。在这种情况下，区分TPE和MPE具有挑战性，并需要对胸膜组织进行组织病理学检查，可能涉及有创性的操作。本研究旨在评估胸腔液ADA与血清C-反应蛋白（C-reactive protein，CRP）（ADA/CRP比值）的诊断准确性，以区分结核性胸腔积液和恶性胸腔积液。此外，我们还研究了ADA/CRP比值是否为ADA增加了诊断价值。 本横断面研究于2021年7月至2022年2月在达卡的国家胸病研究所进行，包括经诊断的TPE和MPE患者。建立了一个接收器操作特征曲线（Receiver Operating Characteristic curve，ROC曲线）以确定TPE。使用净重分类改善（net reclassification improvement，NRI）和综合判别改善（integrated discrimination improvement，IDI）评估了ADA/CRP比值对ADA的增值作用。所有检验的p值小于0.05被认为有统计学意义。 本研究纳入了59名患者，其中31例为TPE，28例为MPE。在TPE患者中，胸腔液ADA与血清CRP比值和胸腔液ADA水平显著增高，但TPE和MPE患者的血清CRP水平之间没有显著差异。在>1.25的截断值下，胸腔液ADA与血清CRP比值对TPE的诊断具有93.8%的敏感性、85.2%的特异性，以及88.2%的阳性预测值和92%的阴性预测值，ROC曲线下的面积（AUC）为0.94。NRI和IDI分析显示了ADA/CRP对ADA的增值诊断价值。 本研究表明，ADA/CRP比值提高了ADA对TPE的诊断效用。© 2023. BioMed Central Ltd., part of Springer Nature.

Tuberculous pleural effusion (TPE) and malignant pleural effusion (MPE) may occasionally show similar cytological and biochemical picture including ADA. In such cases, differentiating TPE and MPE is challenging and needs histopathology of pleural tissue which may involve invasive procedures. The present study aims to evaluate the diagnostic accuracy of pleural fluid ADA to serum CRP (ADA/CRP) ratio to discriminate between tuberculous and malignant pleural effusion. In addition, we investigated whether the ratio ADA/CRP adds diagnostic value to ADA.This cross-sectional study was conducted in the National Institute of Diseases of the Chest and Hospital (NIDCH), Mohakhali, Dhaka, from July 2021 to February 2022 on diagnosed patients of TPE and malignant pleural effusion MPE. A receiver operating characteristic curve (ROC) was constructed for identifying TPE. The added value of the ADA/CRP ratio to ADA was evaluated using the net reclassification improvement (NRI) and integrated discrimination improvement (IDI). A value of p < 0.05 was considered statistically significant for all tests.Fifty-nine patients were enrolled in this study, of which 31 had TPE, and 28 had MPE. Pleural fluid ADA to serum CRP ratio and pleural fluid ADA level was significantly higher in patients with TPE, but there was no significant difference in serum CRP levels between patients with TPE and MPE. At cut off value of > 1.25, pleural fluid ADA to serum CRP ratio had a sensitivity of 93.8%, specificity of 85.2%, and positive and negative predictive values were 88.2% and 92% respectively, in the diagnosis of TPE and area under ROC curve (AUC) was 0.94. The NRI and IDI analyses revealed added diagnostic value of ADA/CRP to ADA.This study shows that the ADA/CRP ratio improves the diagnostic usefulness of ADA for TPE.© 2023. BioMed Central Ltd., part of Springer Nature.