Assistant Professor, Department of Pulmonary Medicine, SKIMS, Soura, Srinagar, Jammu and Kashmir, India, Corresponding Author.
Senior Resident, Department of General Medicine, SKIMS, Soura, Srinagar, Jammu and Kashmir, India.
J Assoc Physicians India. 2024 Mar;72(3):14-17. doi: 10.59556/japi.72.0333.
Exudative pleural effusions are commonly encountered in clinical practice, but in about one-fourth of cases, etiology remains elusive after initial evaluation. Medical thoracoscopy with semirigid thoracoscope is a minimally invasive procedure with high diagnostic yield for diagnosing pleural diseases, especially these undiagnosed exudative pleural effusions. In tubercular endemic areas, often, these effusions turn out to be tubercular, but the diagnosis of tubercular pleural effusion is quite challenging due to the paucibacillary nature of the disease. Although culture is the gold standard, it is time-consuming. Cartridge-based nucleic acid amplification test (CBNAAT) is a novel rapid diagnostic test for tuberculosis (TB) and has been recommended as the initial diagnostic test in patients suspected of having extrapulmonary TB (EPTB).
We conducted a prospective observational study of 50 patients with undiagnosed pleural effusion admitted to our tertiary care hospital. The primary aim of the study is to evaluate the diagnostic performance of CBNAAT on thoracoscopic guided pleural biopsy and compare it with conventional diagnostic techniques like histopathology and conventional culture.
Of 50 undiagnosed pleural effusions, TB (50%) was the most common etiology. The overall diagnostic yield of semirigid thoracoscopy in this study was 74%. Our study showed that CBNAAT of pleural biopsies had a sensitivity of 36% only but a specificity of 100%. The sensitivity of CBNAAT was not far superior to the conventional culture.
Tuberculosis (TB) is a common cause of undiagnosed pleural effusion in our set-up. CBNAAT testing of pleural biopsy, though, is a poor rule-out test for pleural TB, but it may aid in the early diagnosis of such patients.
渗出性胸腔积液在临床实践中很常见，但在初始评估后，仍有约四分之一的病例病因难以确定。半刚性胸腔镜下的内科胸腔镜检查是一种微创程序，对诊断胸膜疾病，尤其是这些未明确病因的渗出性胸腔积液，具有较高的诊断率。在结核流行地区，这些胸腔积液通常是结核性的，但由于疾病的菌量较少，结核性胸腔积液的诊断极具挑战性。尽管培养是金标准，但它很耗时。基于试剂盒的核酸扩增检测（CBNAAT）是一种用于诊断结核病（TB）的新型快速诊断检测方法，已被推荐为疑似患有肺外结核（EPTB）患者的初始诊断检测方法。
我们对 50 例因胸腔积液未明确病因而入住我院的患者进行了一项前瞻性观察性研究。该研究的主要目的是评估 CBNAAT 在胸腔镜引导下胸膜活检中的诊断性能，并将其与组织病理学和常规培养等传统诊断技术进行比较。
在 50 例未明确病因的胸腔积液中，TB（50%）是最常见的病因。本研究中半刚性胸腔镜的总体诊断率为 74%。我们的研究表明，胸膜活检的 CBNAAT 仅具有 36%的敏感性，但特异性为 100%。CBNAAT 的敏感性并不优于常规培养。
在我们的研究中，TB 是胸腔积液未明确病因的常见原因。然而，胸膜活检的 CBNAAT 检测对胸腔结核的排除试验效果不佳，但可能有助于早期诊断此类患者。
