Chegou Novel N, Walzl Gerhard, Bolliger Chris T, Diacon Andreas H, van den Heuvel Michel M
Department of Biomedical Sciences, Division of Molecular Biology and Human Genetics, DST/NRF Centre of Excellence for Biomedical Tuberculosis Research, US/MRC Centre for Molecular and Cellular Biology, Stellenbosch University, Cape Town, South Africa.
Respiration. 2008;76(2):131-8. doi: 10.1159/000128575. Epub 2008 Apr 24.
Pleural tuberculosis (TB) remains difficult to diagnose despite numerous diagnostic tools. Recently, in vitro interferon (IFN)-gamma-based assays have been introduced in the diagnosis of latent TB, but these techniques have not been established in the diagnosis of active TB disease, including pleural TB.
It was the aim of this study to assess the accuracy of the commercially available QuantiFERON TB Gold assay and adapted variants of the assay, using pleural fluid or isolated pleural fluid cells for the diagnosis of pleural TB.
We recruited 66 consecutive patients with a pleural effusion of unknown cause presenting at a tertiary academic health care centre in Cape Town, South Africa, a high prevalence area of TB. Blood and pleural fluid were collected at presentation for IFN-gamma assays and the results evaluated for diagnostic accuracy.
The clinical diagnosis was TB in 30 (46%), malignancy in 20 (30%), parapneumonic effusion/empyema in 8 (12%) and effusion due to other causes in 8 patients (12%). Ex vivo pleural fluid IFN-gamma levels accurately identified TB in all patients and were superior to the QuantiFERON In Tube assay using blood and pleural fluid (73 and 57% sensitivity, with 71 and 87% specificity, respectively) and the QuantiFERON Gold assay applied to isolated pleural fluid cells (100% sensitivity and 67% specificity).
The ex vivo pleural fluid interferon-gamma level is an accurate marker for the diagnosis of pleural TB, and the QuantiFERON TB Gold assay performed with peripheral blood or adapted for pleural fluid cells does not add diagnostic value.
尽管有众多诊断工具，但胸膜结核（TB）的诊断仍然困难。最近，基于体外干扰素（IFN）-γ的检测方法已被用于潜伏性结核的诊断，但这些技术尚未在包括胸膜结核在内的活动性结核疾病的诊断中得到确立。
本研究旨在评估商用QuantiFERON TB Gold检测方法及其改良变体使用胸水或分离的胸水细胞诊断胸膜结核的准确性。
我们连续招募了66例因不明原因胸腔积液就诊于南非开普敦一家三级学术医疗中心的患者，该地区是结核病高发区。就诊时采集血液和胸水进行IFN-γ检测，并对结果的诊断准确性进行评估。
临床诊断为结核的有30例（46%），恶性肿瘤20例（30%），类肺炎性胸腔积液/脓胸8例（12%），其他原因导致的胸腔积液8例（12%）。体外胸水IFN-γ水平能准确诊断所有结核患者，优于使用血液和胸水的QuantiFERON In Tube检测方法（敏感性分别为73%和57%，特异性分别为71%和87%）以及应用于分离的胸水细胞的QuantiFERON Gold检测方法（敏感性100%，特异性67%）。
体外胸水干扰素-γ水平是诊断胸膜结核的准确标志物，使用外周血或改良用于胸水细胞的QuantiFERON TB Gold检测方法不增加诊断价值。
