Abstract
Background
Progressive multifocal leukoencephalopathy (PML) is a demyelinating disease caused by JC virus (JCV) reactivation with a high mortality and no definitive treatment. HIV-1 infection represents the most common underlying immunosuppressive condition associated with PML.
Methods
Nested PCR (nPCR) and real time PCR (qPCR) for JCV DNA was performed on serial plasma samples obtained from 14 HIV patients with a clinical diagnosis of PML and 27controls (HIV patients without PML matched to cases on CD4 count, viral load, and treatment status).
Results
nPCR detected JCV LT DNA in 4/14 (29%) PML cases at disease onset but no controls (p = 0.003). JCV LT DNA was detected via qPCR in 11/14 (78%) PML patients at disease onset and 4/27 (15%) controls (p < 0.001). The availability of plasma samples collected prior to PML diagnosis allowed a preliminary evaluation of the predictive utility of JCV LT qPCR. Logistic regression analysis revealed proximity to PML diagnosis, duration of known HIV infection, absence of a prior AIDS defining illness and absence of cART to be independently associated with a positive qPCR result (p<0.001; R2 = 0.35). Overall, JCV LT qPCR was more likely to be positive in the 8 months prior to PML diagnosis compared with earlier samples (p = 0.01).
Conclusions
qPCR is more sensitive for detecting JCV DNA than nPCR. Detection of JCV DNA in plasma of HIV infected patients via qPCR may represent a valuable test for diagnosing patients at increased risk of developing PML.