Evaluation of polymerase chain reaction for diagnosis of "tuberculous pleurisy"

Differential diagnosis between tuberculous pleurisy [TBP] and non-tuberculosis pleural effusion represents a critically important clinical problem. In recent years, several noninvasive methods have been found for diagnosis of tuberculous pleurisy. This study aimed to evaluate the value of detection of the genome of Mycobacterium tuberculosis [MTB] by polymerase chain reaction [PCR] method for the diagnosis of tuberculous pleurisy and compare the results with those of conventional methods. In this cross-sectional study, we studied 62 patients [42 men and 20 women] with pleural effusion in Ghaem Hospital, affiliated to Mashhad University of Medical Sciences from January 2006 to June 2007. A total of 20 patients had tuberculous pleurisy [45.4%], 15 patients had malignant pleural effusion [34%], 3 patients had pleural effusion with various "non-tuberculosis non-malignant" etiologies [6.8%] and 6 patients had transudative pleural effusion [13.6]. The sensitivity, specificity, positive predictive value and negative predictive value of PCR in tuberculous pleurisy were 85%, 100%, 100% and 88.8%, respectively. The value of PCR test and pleural biopsy was similar in the diagnosis of TBP. However, PCR detected MTB in pleural effusion when conventional pleural biopsy failed to do so

[Evaluation of gamma-interferon in diagnosis of tuberculosis pleurisy]

Differential diagnosis between Tuberculosis pleurisy and Non Tuberculoses pleural effusion can be sometimes difficult and needs invasive diagnostic methods. In recent years, several biological markers have been found to be diagnostic markers of Tuberculosis pleurisy. The aim of this study was assessment of the value of Gamma-Interferon in the diagnosis of TB pleurisy. We studied 70 patients with pleural effusion who had been admitted to Ghaem hospital, Mashhad University of Medical Sciences, Mashhad, Iran. Interferon gamma level was measured by "ELISA' method. The diagnosis of tuberculosis was based on microbiologic study of pleural fluid plus pleural biopsy. Altogether Twenty patients had tuberculosis pleurisy [44.44%], 21 patients had malignant pleural effusion [46.67%] and 4 patients had pleural effusion with various non TB non malignant etiologies [8.9%]. The sensitivity, specificity of Gamma-Interferon in TB pleurisy were 60% and 96% respectively. INF gamma is a valuable indicative marker for diagnosis of tuberculosis pleurisies' but we should consider situations with high level of INF gamma without any evidence of TB and also Tuberculosis pleurisy patients with INF gamma level lower than diagnostic threshold