Amplification of DNA of Mycobacterium tuberculosis from peripheral blood of patients with pulmonary tuberculosis.

Sputum examination for rapid diagnosis of pulmonary tuberculosis is not always satisfactory. We examined peripheral blood with the polymerase chain reaction (PCR). Blood samples were collected from 8 consecutive patients with suspected pulmonary tuberculosis and from 18 healthy controls, half of whom were tuberculin skin-test positive. All 8 patients had evidence of circulating Mycobacterium tuberculosis DNA in the lymphocyte fraction of peripheral blood, and positive sputum cultures indicating active pulmonary tuberculosis. None of the healthy controls had positive PCR results. This PCR technique may prove useful for the rapid diagnosis of tuberculosis.