CEREBROSPINAL-FLUID HIV-1 P24 ANTIGEN AND CULTURE - SENSITIVITY AND SPECIFICITY FOR AIDS DEMENTIA COMPLEX

We prospectively evaluated 94 patients with AIDS-dementia complex (ADC ) and a smaller group of 27 patients with other HIV-1 related neurolog ical conditions to determine the usefulness of cerebrospinal fluid (CS F) p24 antigen and HIV-1 culture in the diagnosis of ADC. The presence of ADC correlated with detectable CSF p24, but not with a positive cu lture. However, only 54% of the patients with severe or end stage (sta ges 3 and 4) ADC had detectable CSF p24 and only 25% had a positive cu lture. Among those with detectable CSF p24, there was no discernible r elationship between the severity of ADC and the amount of CSF p24. The diagnostic sensitivity of CSF p24 in ADC was 21% whereas the specific ity was 98%. CSF HIV-1 culture had a sensitivity of 30% and a specific ity of 80%. To address the possibility of binding of p24 in immune com plexes, thereby escaping detection, an acid hydrolysis procedure was p erformed on the CSF and serum samples. This did not, however, make an appreciable difference in the detection rate of p24. To delineate whet her the finding of cell free virus in the CSF was associated with ADC, CSF culture for HIV-1 was performed on both cell depleted and cell as sociated fractions. It was uncommon for CSF to be culture positive in only the cell free fraction and there was no relationship to the prese nce or severity of ADC.