Bart Swinnen1, Veroniek Saegeman2, Kurt Beuselinck3, Anke Wouters4, Gert Cypers5, Geert Meyfroidt6, Maarten Schrooten7. 1. Neurology Department, University Hospitals Leuven, Leuven, Belgium; KU Leuven - University of Leuven, Department of Neurosciences, Experimental Neurology and Leuven Brain Institute (LBI), Leuven, Belgium; VIB, Center for Brain & Disease Research, Laboratory of Neurobiology, Leuven, Belgium. Electronic address: bart.swinnen@uzleuven.be. 2. Department of Laboratory Medicine, University Hospitals Leuven, Leuven, Belgium. Electronic address: veroniek.saegeman@uzleuven.be. 3. Department of Laboratory Medicine, University Hospitals Leuven, Leuven, Belgium. Electronic address: kurt.beuselinck@uzleuven.be. 4. Neurology Department, University Hospitals Leuven, Leuven, Belgium; KU Leuven - University of Leuven, Department of Neurosciences, Experimental Neurology and Leuven Brain Institute (LBI), Leuven, Belgium; VIB, Center for Brain & Disease Research, Laboratory of Neurobiology, Leuven, Belgium. Electronic address: anke.wouters@uzleuven.be. 5. Department of Neurology, OLV Hospital Aalst, Aalst, Belgium. Electronic address: gert.cypers@olvz-aalst.be. 6. Intensive Care Medicine Department, University Hospitals Leuven, Leuven, Belgium. Electronic address: geert.meyfroidt@uzleuven.be. 7. Neurology Department, University Hospitals Leuven, Leuven, Belgium; Laboratory for Cognitive Neurology, Department of Neurosciences, KU Leuven, Leuven, Belgium. Electronic address: maarten.schrooten@uzleuven.be.
Abstract
OBJECTIVE: To assess the predictive value of JC virus (JCV) PCR in cerebrospinal fluid (CSF) in the diagnosis of progressive multifocal leukoencephalopathy (PML). METHODS: We conducted a retrospective database query to identify patients with positive CSF JCV PCR. Clinical features, final diagnosis and quantitative PCR results were obtained. RESULTS: A positive CSF JCV PCR had a PPV of 10.4% for the diagnosis of PML. A weakly positive PCR had a PPV of 1.6%, whereas a moderately to highly positive PCR had a PPV of 92.3%. A PPV of 0.0% was observed in immunocompetent patients and in patients without compatible clinical or radiological features. CONCLUSIONS: A false-positive CSF JCV PCR is highly prevalent in our clinical practice. This test should be reserved for patients with a clinical suspicion of PML and the quantitative result of the PCR should be taken into account when making the diagnosis of PML.
OBJECTIVE: To assess the predictive value of JC virus (JCV) PCR in cerebrospinal fluid (CSF) in the diagnosis of progressive multifocal leukoencephalopathy (PML). METHODS: We conducted a retrospective database query to identify patients with positive CSF JCV PCR. Clinical features, final diagnosis and quantitative PCR results were obtained. RESULTS: A positive CSF JCV PCR had a PPV of 10.4% for the diagnosis of PML. A weakly positive PCR had a PPV of 1.6%, whereas a moderately to highly positive PCR had a PPV of 92.3%. A PPV of 0.0% was observed in immunocompetent patients and in patients without compatible clinical or radiological features. CONCLUSIONS: A false-positive CSF JCV PCR is highly prevalent in our clinical practice. This test should be reserved for patients with a clinical suspicion of PML and the quantitative result of the PCR should be taken into account when making the diagnosis of PML.