Progressive multifocal leukoencephalopathy (PML) is caused by the JC virus which lyses infected oligodentrocytes, causing demyelination of axons. PML most commonly occurs in HIV+ patients with low CD4 counts. Diagnosis involves clinical features, radiology showing white matter lesions, and confirmation via PCR or histopathology detecting the JC virus. Currently there is no effective treatment for PML and prognosis is poor, though cART can help prevent onset in HIV+ patients by improving immune function.

1. Progressive Multifocal
Leukoencephalopathy
Ade Wijaya, MD – February 2020

2. Introduction
 First described in the late 1950s [Astrom et al. 1958].
 The causative virus was first isolated in 1971 [Padgett et al. 1971] and named JC
virus (JCV)
 The hallmark of PML is demyelination of axons caused by the lysis of infected
oligodentrocytes by JCV.
 HIV + with low CD4

3. JC Virus
 JCV is a polyomavirus, genetically related to BK virus (BKV) and simian virus 40
(SV40), composed of a 5–13 kb doublestranded circular DNA enclosed in a capsid
without a lipoprotein envelope.
 Oral / fecal transmission
 The JCV archetype can infect various cell types, including brain cells [Tominaga
et al. 1992; O’Neill et al. 2003; Newman and Frisque, 1997].

5. Clinical Features

6. Radiology

7. Diagnostic Criteria

8. Diagnosis

10. Management
 Currently there is neither a specific prophylaxis for PML, nor an effective anti-JCV
treatment in the setting of PML
 In the HIV+ population, timely treatment with highly effective cART is an effective
way of preventing the onset of acquired immune deficiency syndrome (AIDS) and
with it PML
 In the absence of an effective anti-JCV treatment, PML outcomes depend entirely
on an individual’s capacity to recover immune system function and respond to JCV

11. Summary
 Demyelination of axons caused by the lysis of infected oligodentrocytes by JCV
 HIV + with low CD4
 Diagnosis: Clinical; Radiology; PCR; Histopathology
 Currently there is neither a specific prophylaxis for PML, nor an effective anti-JCV
treatment in the setting of PML
 Poor prognosis

12. THANK YOU
References:
Pavlovic D, Patera AC, Nyberg F, Gerber M, Liu M, Progressive Multifocal Leukeoncephalopathy Consortium. Progressive multifocal leukoencephalopathy: current treatment options and future
perspectives. Therapeutic advances in neurological disorders. 2015 Nov;8(6):255-73.
Tavazzi E, White MK, Khalili K. Progressive multifocal leukoencephalopathy: clinical and molecular aspects. Reviews in medical virology. 2012 Jan;22(1):18-32.