Identification of HIV patients with active pulmonary tuberculosis using urine based polymerase chain reaction assay

BACKGROUND: Despite the increased dissemination of tuberculosis among HIV infected patients, the diagnosis is difficult to establish. Traditional microbiological methods lack satisfactory sensitivity. We have developed a highly sensitive and specific nested polymerase chain reaction (PCR) capable of detecting Mycobacterium tuberculosis DNA in urine specimens and have used this test to examine urine specimens from HIV patients with active pulmonary tuberculosis. METHODS: Urine specimens from 13 HIV infected patients with microbiologically proven active pulmonary tuberculosis, 10 AIDS patients with non-tuberculous mycobacterial infection (documented by blood culture), 53 AIDS patients with no evidence of mycobacterial disease, and 80 healthy subjects (25 with positive skin test to purified protein derivative) were tested for M tuberculosis using PCR, acid fast staining (AFS), and culture. RESULTS: Of the urine specimens from patients with active tuberculosis, all tested positive by PCR, two by culture, and none by AFS. No reactivity was observed in urine specimens from patients with non-tuberculous mycobacterial infection. Of the 53 AIDS patients without mycobacterial infection, one had a positive urine PCR. Normal subjects were all negative. CONCLUSIONS: Urine based nested PCR for M tuberculosis may be a useful test for identifying HIV patients with pulmonary tuberculosis.