Challenges in pleural tuberculosis diagnosis: existing reference standards and nucleic acid tests.

Pleural tuberculosis (pTB) is a grave form of extrapulmonary tuberculosis. Microbiological tests are usually found to be inadequate for pTB diagnosis. The absence of a uniform 'composite reference standard' is challenging; therefore, diagnosis is usually performed using a combination of diversified criteria. Nucleic acid tests vary in diagnostic accuracy and have not yet been integrated into clinical decision making. This review assesses the varied criteria used for pTB classification and the challenges afflicting pleural fluid-based DNA diagnostic tests, namely, PCR and Xpert® MTB/RIF. In the 58 studies (PCR: n = 33; Xpert: n = 25) analyzed, reference standards were heterogeneous and PCR/Xpert pooled sensitivity values (range: 0-100%) were inadequate. However, the consistent high specificity of Xpert (range: 90-100%) indicated its utility as a 'rule-in' test. There is an urgent need to evaluate existing and new molecular tests in well-designed studies  to accurately assess their utility for pTB diagnosis. To conclude, rapid and accurate tests are warranted for pTB diagnosis.

The inconsistent definitions used for tuberculosis in the medical literature.

In order to assess the confusion attendant with current definitions of extrapulmonary tuberculosis, pleural and miliary disease, a set of 37 papers published which analyzed disease states were assessed for how the terms adhered to official definitions of the American Thoracic Society, the World Health Organization, and the Centers for Disease Control. The findings showed uncertainties in the classification of extrapulmonary disease, a frequent inconsistency in the inclusion of pleural disease within pulmonary rather than extrapulmonary disease, and the ambivalent use of the terms pleural and disseminated tuberculosis. Further attention by editors and authors is needed in the use of tuberculosis definitions.

Relación entre los niveles de adenosina deaminasa y desarrollo de engrosamiento pleural residual en tuberculosis pleural

Introducción: el engrosamiento pleural residual (EPR) es frecuente en tuberculosis pleural (TBCP) y no es claro si puede pronosticarse con la toracentesis inicial. Objetivo: evaluar la relación entre los índices de inflación y la activación linfocitaria pleural especialmente la adenosina deaminasa (ADA) y el desarrollo de EPR en TBCP. Tipo de estudio: observacional analítico de cohorte prospectiva. Lugar de estudio: programa de tuberculosis en el hospital de referencia. Material y métodos: pacientes con diagnóstico de TBCP a quienes se les realizó toracentesis incluyendo determinación de ADA y fueron tratados y controlados sin recibir glucocorticoides. Se definió EPR con métodos radiológicos. Los datos se recolectaron en forma prospectiva. La relación entre predictores y EPR se evaluó con prueba no paranétrica con una p<0,01 de significativa. Resultados: durante 48 meses, 57 pacientes cumplieron los criterios de inclusión; el diagnóstico se realizó en 84 por ciento con biopsia pleural. Se desarrolló EPR en 33 pacientes (58 por ciento) y no hubo EPR en 24 (42 por ciento). Los valores de LDH, proteínas, porcentaje de linfocitos y concentración de glucosa fueron similares en ambos grupos. La concentración de ADA fue similar (grupo con EPR:97 más menos 48; grupo sin EPR: 106 más menos 45; p=0,48, Mann-Whitney) en los dos grupos y no se encontró un punto de corte con apropiada discriminación para pronosticar EPR. Conclusión: en este grupo de pacientes ningún hallazgo de la toracentesis inicial se relacionó con el desarrollo de EPR. Los resultados son similares a los informados por otros investigadores, pero es la primera vez que se describen para el nivel de ADA pleural

[Comparative study of acute and chronic forms of pleural tuberculosis]. / Estudio comparativo entre formas agudas y crónicas de tuberculosis pleural.

To analyze whether a characteristic pattern distinguishes acute forms (symptoms starting no more than one week earlier) and subacute or chronic forms (symptoms lasting more than one week) of pleural tuberculosis (PT) in our practice. Retrospective analysis of 102 cases of PT diagnosed between 1986 and 1992, comparing the findings of case histories, imaging, pleural biochemistry and cytology, microbiology of sputum, pleural biopsy and fluid, anatomy and pathology studies of the biopsy specimens, course of disease, response to treatment and sequelae after one year and a half. Thirty-two patients (31.4%) had acute PT and 70 (68.6%) had chronic forms. LDH levels and the percentage of pleural nuclear polymorphism were higher in acute cases, while the concurrence of systemic involvement and lymphocytic predominance was more often seen in chronic cases. Other data analyzed were similar in both groups. No specific clinical or X-ray profiles or differences in course of disease and response to treatment distinguishes between acute and chronic forms of PT after 7 days. Only LDH levels and cytology results differentiated acute forms and, occasionally, such cases were indistinguishable from pneumonia-like effusion.

Valor diagnóstico de la adenosín deaminasa en pacientes con pleuritis tuberculosa en la ciudad de Medellín 1991-1993

Se realizó un estudio observacional, descriptivo y prospectivo en 145 pacientes: 88 con diagnóstico de tuberculosis pleural confirmado por medio de cultivo o biopsia y 57 con derrame pleural no tuberculoso. Fue practicado en varias instituciones de salud de la ciudad de medellín durante el período de 1991-1993, con el fin de valorar la utilidad de la adenosín deaminasa en el diagnóstico de tuberculosis pleural. Se obtuvo para dicha prueba una sensibilidad de 92.04 por ciento y una especificidad de 89.47 por ciento, mostrando que la adenosín deaminasa es una importante herramienta diagnóstica de bajo costo en nuestro medio

[The clinical picture of pleural tuberculosis (based on the results of thoracoscopy in 500 patients with a pleural exudate)]. / O klinicheskoi kartine tuberkuleza plevry (po itogam torakoskopii u 500 bol'nykh s plevral'nym vypotom).

The author presents results of 500 thoracoscopies performed in 500 patients with pleural effusion. Tuberculosis and malignant tumors prevailed (51.8 and 20.8% respectively). Endoscopic examination of pleural cavity amplified by pleural biopsy and cytohistological study of obtained material was shown to be highly effective. In the author's opinion, wet pleurisy is sure to be a surgical problem. To solve it, he considers necessary to allocate 8-10 hospital beds for every 1.5 million of population (in thoracal department of surgical and pulmonological centres, TB dispensaries) right up to organization of pleural pathology departments.

[Classification of pleurisy]. / O klassifikatsii plevrita.

A draft scheme for classification of pleurisy is described. It includes (1) pleurisy form, (2) qualitative characteristics of pleural exudate, (3) pleurisy topography, (4) etiology, (5) clinical characteristics of the pleurisy process, (6) residual postpleuritic lesions and (7) functional disorders in the lungs and heart. Brief comments on the classification system are presented.