Nested PCR for the rapid detection of TB from pleural fluid at HUKM Malaysia

The aim of the present study is rapid detection of tuberculosis from pleural effusion of suspected patients. Molecular technique Nested Polymerase Chain Reaction (PCR) was used for the purpose. A total of 67 pleural fluid collected at Hospital University Kebangsaan Malaysia during May 2005 to October 2006 were sent to Microbiology Laboratory enrolled in the study. Detection rate of Mycobacterium tuberculosis in pleural effusion was 0% by acid-fast bacilli (AFB) staining and 1.5% by culture on Lowenstein-Jensen medium. Mycobacterium tuberculosis was detected by PCR in 9% of the cases. PCR of pleural fluid had 19% sensitivity and 96% specificity, compared to AFB staining (0% sensitivity and 100% specificity) and culture (4% sensitivity and 100% specificity). PCR also has 67% Positive Predictive Value (PPV) and 72% Negative Predictive Value (NPV) in detecting Mycobacterium tuberculosis. Culture ofpleural fluid has 100% PPV and 71% NPV while AFB staining has 0% PPV and 31% NPV. This preliminary study showed that PCR is a rapid method for detection of Mycobacterium tuberculosis in pleural fluid but its sensitivity is not up the marked.