Polymerase chain reaction in pulmonary tuberculosis: Sputum versus blood

ABSTRACT

- The aim of this work is to study the role of polymerase chain reaction [PCR] in the diagnosis of pulmonary tuberculosis and to compare the sensitiviity of its utility in sputum and blood of patients with pulmonary tuberculosis. The present study entailed 25 patients with recently diagnosed pulmonary tuberculosis. All patients were subjected to sputum culture on Lownstein Jensen Medium. Radiological investigation, PCR assay for deteection of mycobacterial DNA in sputum and peripheral blood. The current study revealed that sputum PCR assay for mycobacterium tuberculosis was positive in 24 patients out of 25 patients positive ZN stain and culture with sensitivity 96%. As regard blood PCR assay comparing to positive sputum culture. 20 cases were positive out of 25 positive cases by ZN stain and culture with sensitive 80%. The sensitivity of blood PCR as compared sputum PCR was 80.33% while specificity of blood PCR to sputum PCR was 100%. Sputum PCR was found to be a rapid and sensitive technique for the diagnosis of pulmonary tuberculosis. Blood PCR in patients with mycobacterium tuberculosis may be considered as an additional effective diagnosis tool with results comparable with sputum PCR