Role of IS6110-targeted PCR, culture, biochemical, clinical, and immunological criteria for diagnosis of tuberculous meningitis

An open prospective clinical, microbiological, and molecular analysis of a national molecular diagnostic service for tuberculous meningitis (TBM) usin g an in-house IS6110-targeted PCR for molecular "Fastrack" diagnosis was ca rried out. Between April 1997 and June 1998. Consecutive cerebrospinal flui d (CSF) samples from 131 patients were assessed, Against a culture on the s ame sample, PCR had a sensitivity of 75% and a specificity of 94%. Of sampl es from patients classified as definite or probable TBM cases based on clin ical criteria, 81% had raised CSF protein levels and 73% had a lymphocytosi s, although 57% of all submitted samples showed a raised lymphocyte count. While only 46% had a CSF glucose level below the normal range, the CSF gluc ose level was significantly lower (P = 0.0281) than in cases of meningitis of other etiologies, Levels of tumor necrosis factor alpha were also found to be significantly raised in definite or probable TBM cases (P = 0.028), w hile adenosine deaminase levels were not. The study showed IS6110-targeted PCR to be a rapid, sensitive, and specific test in routine use for the diag nosis of TBM.