TABLE 2.

Diagnostic accuracy of nested PCR detection of JCV DNA on CSF samples of repeated lumbar punctures for diagnosis of PML in HIV-infected patients according to study era^a

Parameter	Results for:		P
	Pre-HAART era	HAART era
Positive detection rateb	17/19 (89.5 [75.5-103.5])	23/40 (57.5 [42.1-72.9])	0.014
Specificityc (%)	82/83 (98.8 [96.4-101.2])	141/141 (100)	NS
Negative predictive value (%)	98	89	0.03
Positive predictive value (%)	95	100	NS

^aPre-HAART era, January 1992 to December 1995; HAART era, September 1996 to December 2002. JCV⁺ and JCV⁻ denote positive and negative JCV DNA assay results in CSF, respectively. NS, not significant.

^bCalculated as the number of JCV⁺/suspected PML patients (% [95% CI]).

^cCalculated as the number of JCV⁻/HIV⁺ controls (% [95% CI]).