DIAGNOSIS OF TUBERCULOUS MENINGITIS BY DETECTION OF IMMUNOGLOBULIN-G ANTIBODIES TO PURIFIED PROTEIN DERIVATIVE AND LIPOARABINOMANNAN ANTIGEN IN CEREBROSPINAL-FLUID

Enzyme-linked immunosorbent assay of immunoglobulin G (IgG) activity i n cerebrospinal fluid (CSF) and sera was conducted prospectively in 27 patients with tuberculous meningitis (TBM) by using purified protein derivative (PPD) and lipoarabinomannan (LAM) antigens, from January 19 89 to August 1990. 29 patients with aseptic meningitis and 49 patients with non-inflammatory neurological illnesses served as controls. All patients had a computed tomography (CT) scan of the head before a lumb ar puncture. The IgG antibodies to the antigens were significantly ele vated in TBM, and the reactivity was more frequently positive in the C SF than in the sera, suggesting a local synthesis of IgG in the centra l nervous system (CNS). The sensitivity and the specificity for the di agnosis of TBM were 59.2% and 93.9% for PPD antigen, and 85.2% and 95. 9% for LAM antigen, respectively. Assay of IgG reactivity to LAM antig en was clinically very useful for the early diagnosis of TBM and was s uperior to PPD for detecting the serological evidence of TBM.