Chalhoub M, Cruz A A, Marcílio C, Netto M B
Hospital Octávio Mangabeira, SESAB-Bahia.
Rev Assoc Med Bras (1992). 1996 Jul-Sep;42(3):139-46.
Pleural effusion (PE) is a common problem in medical practice. Transudative effusions usually do not present difficulty in diagnosis, in most populations. Exudative PE however, require careful differential diagnosis that include necessarily tuberculosis and metastatic cancer.
We have conducted a cross-sectional study of 221 patients with persistent PE, in order to evaluate accuracy of determining adenosine deaminase activity (ADA) for diagnosis of tuberculosis pleuritis. This group of patients, taken mostly from the State Hospital for pulmonary diseases, consecutively, was constituted as follows: 1) Tuberculosis (confirmed, n = 150; likely, n = 9); 2) Cancer (confirmed, n = 21; likely, n = 16; Lymphoma = 3); and 3) Miscellaneous (n = 22). All individuals were submitted to clinical examination, chest X-ray, blood tests, and underwent thoracocentesis with pleural biopsy. Pleural fluids were analyzed by routine tests plus determination of ADA activity using Giusti's Method.
In agreement with previous reports we have found 40 U/L to be the best cutoff point according to a Receiver Operating Curve (ROC) analysis of our data. Sensitivity of ADA activity < or = 40 U/L was 93.3% and specificity 93.5%, resulting in a positive predictive value of 97.2% and a negative predictive value of 85.3%, in this specific population of patients, when taking into account only the individuals with confirmed tuberculosis by histopathology or culture. Three out of the 4 patients with elevated ADA without tuberculosis had lymphoma.
ADA determination in pleural fluids, a quick and inexpensive technique, is shown to be an accurate method for identifying tuberculosis pleuritis. Our findings are comparable to reports from other series, and stress how useful it is to incorporate this test to the routine evaluation of pleural effusions in areas of high incidence of tuberculosis.
胸腔积液（PE）是医学实践中的常见问题。在大多数人群中，漏出性胸腔积液通常在诊断上不存在困难。然而，渗出性胸腔积液需要仔细的鉴别诊断，其中必然包括结核病和转移性癌症。
我们对221例持续性胸腔积液患者进行了一项横断面研究，以评估测定腺苷脱氨酶活性（ADA）对诊断结核性胸膜炎的准确性。这组患者主要来自国家肺病医院，按顺序组成如下：1）结核病（确诊，n = 150；可能，n = 9）；2）癌症（确诊，n = 21；可能，n = 16；淋巴瘤 = 3）；3）其他（n = 22）。所有个体均接受临床检查、胸部X线检查、血液检查，并接受胸腔穿刺及胸膜活检。胸腔积液通过常规检查以及使用朱斯蒂方法测定ADA活性进行分析。
根据对我们数据的受试者操作特征曲线（ROC）分析，与先前报告一致，我们发现40 U/L是最佳临界值。在该特定患者群体中，仅考虑经组织病理学或培养确诊为结核病的个体时，ADA活性≤40 U/L的敏感性为93.3%，特异性为93.5%，阳性预测值为97.2%，阴性预测值为85.3%。4例ADA升高但无结核病的患者中有3例患有淋巴瘤。
胸腔积液中ADA的测定是一种快速且廉价的技术，被证明是识别结核性胸膜炎的准确方法。我们的研究结果与其他系列报告相当，并强调了在结核病高发地区将该检测纳入胸腔积液常规评估的实用性。
