Comparative study of amplicor Mycobacterium PCR and conventional methods for the diagnosis of pleuritis caused by mycobacterial infection.

OBJECTIVE: To assess the clinical significance of the Amplicor Mycobacterium system for the diagnosis of mycobacterial infection in patients with pleural fluid, and to compare its usefulness with that of conventional smear and culture methods. DESIGN: Pleural fluid specimens were obtained randomly from in-patients admitted to National Tokyo Hospital between January and December 1996. All the patients were diagnosed with bacterial, histopathological and clinical gold standard. The sensitivity and specificity for diagnosis of mycobacterial infection were evaluated. RESULTS: Seventy-five pleural fluid specimens were obtained. Conventional methods demonstrated a sensitivity of 30.6% and a specificity of 100%, while the Amplicor Mycobacterium demonstrated a sensitivity and specificity of 27.3% and 97.6% respectively. Lactic dehydrogenase, carcinoembryonic antigen, red blood cell, protein, glucose and types of inflammatory cells were not different in Amplicor positive and negative pleural fluid with mycobacterial infection. CONCLUSION: There was not much improvement in the accuracy of diagnosis when Amplicor Mycobacterium was used to diagnose mycobacterial pleuritis among various diseases with pleural fluid; however, the assay time was dramatically reduced with the use of Amplicor Mycobacterium.