Evaluation of in-house polymerase chain reaction assay sensitivity, can it be utilized in limited-resources settings?

Polymerase chain reaction (PCR) assay has widely used for the detection of tuberculosis (TB). This study tried to compare in-house PCR with some well-known commercial PCR kits for detection of TB agent.

Clinical samples obtained from 620 TB suspected patients were analyzed for the diagnosis of Mycobacterium tuberculosis complex (MTC) by in-house PCR. All samples were obtained through pulmonary specimens consisted of 384 sputum, 148 bronchial aspirates and 88 pleural effusions.

Considering culture as a golden criterion, in which its diagnostic sensitivity and specificity of PCR assay were 87.7% and 85.6%, respectively. The findings of this study also indicate 22.1% (137/620) of the specimens were detected as MTC by PCR. Both PCR and culture confirmed presence of MTC in 57 of the samples. In comparison to culture, the diagnostic sensitivity of PCR for sputum was 87.5% (42/48), bronchial aspirates 100% (12/12), and 60% (3/5) for pleural effusions. The sensitivity of in-house PCR method is comparable with the sensitivity of Amplicor and Cobas TaqMan for MTC.

The study illustrates the in-house PCR assay for detection of MTC has high sensitivity and specificity versus approved commercial kits. This could be reliable test in the diagnosis of MTC in resource-limited countries.