Polymerase chain reaction for non-invasive diagnosis of brain mass lesions caused by Mycobacterium tuberculosis: report of five cases in human immunodeficiency virus-positive subjects.

To investigate whether the polymerase chain reaction (PCR) on the IS6110 sequence of Mycobacterium tuberculosis could permit the early and non-invasive diagnosis of tuberculous brain lesions without meningeal involvement in acquired immunodeficiency virus patients, we examined retrospective cerebrospinal fluid (CSF) samples from five patients diagnosed as having cerebral lesions caused by M. tuberculosis. M. tuberculosis deoxyribonucleic acid was detected in CSF samples obtained from each of the patients studied, but in none of the controls. The PCR results coincided with M. tuberculosis isolation from CSF in two patients. In an additional two subjects, culture for M. tuberculosis on CSF was negative, and the diagnosis of central nervous system tuberculosis was achieved by response to specific therapy. In the last patient the PCR result on CSF was confirmed by isolation of M. tuberculosis from brain biopsy. Interestingly, in this patient the CSF did not yield M. tuberculosis isolation when cultured. The data show the value of PCR as a potentially useful approach for the early and rapid diagnosis of cerebral tuberculosis even without meningitis.