Does multiplex polymerase chain reaction increase the diagnostic percentage in osteoarticular tuberculosis? A prospective evaluation of 80 cases.

PURPOSE: Multiplex Polymerase Chain Reaction (MPCR) is a technique in which two or more gene targets are amplified in a single reaction. This has increased sensitivity of diagnosis as a single gene target may be absent in some Mycobacterium tuberculosis strains. METHODS: MPCR using two target genes specific for Mycobacterium tuberculosis, that is, IS6110 and MPB 64, ZN staining and Mycobacterial culture were performed on synovial fluid/pus samples of 80 (three confirmed, 77 suspected) patients of osteoarticular tuberculosis and 25 non tuberculosis patients. RESULTS: MPCR had a sensitivity of 100% in confirmed cases and 81.8% in clinically suspected cases. AFB was positive in one patient and Mycobacterial culture was positive in three patients. MPCR also had 100% specificity; MPB64 was positive in five patients in which IS6110 was negative whereas IS6110 was positive in two patients in which MPB64 was negative. CONCLUSIONS: MPCR is a sensitive and specific method for diagnosis of paucibacilliary conditions such as osteoarticular tuberculosis.