BK Virus-Related Progressive Multifocal Leukoencephalopathy (P03.258)

OBJECTIVE: To gain familiarity with the rare presentation of BK virus-related progressive multifocal leukoencephalopathy. BACKGROUND: BK virus is a member of the Polyomaviridae family and relative of JC virus, the etiologic agent of progressive multifocal leukoencephalopathy. It is found in kidney, lung, eye, liver and brain. Clinical disease is mostly encountered in AIDS or transplant recipients. PCR assays are the standard method of detection. BK viral DNA is rarely reported in samples of CSF, which differs from JC virus, a common finding in PML. We describe a rare case of BK virus-related PML in an HIV patient. DESIGN/METHODS: Case Report. RESULTS: A 36 year-old female diagnosed with HIV in 1997, with CD4 count of 88, on tenofovir/emtricitabine and lopinavir/ritonavir, presented with memory impairment, progressive left-sided hemiparesis, urinary incontinence and new onset seizures. MRI of brain showed asymmetric diffuse increased T2 hyperintensity in deep white matter of both hemispheres involving the corpus callosum. CSF PCR was negative for JC virus. Interestingly, CSF was positive for BK virus. Based on clinical and MRI findings and presence of BK virus in CSF, the diagnosis was most consistent with BK virus-related PML. Two years after her initial diagnosis, she presented to the hospital again with increased seizures. MRI of brain was unchanged. Repeat CSF for BK virus was negative. Her seizure medications were adjusted and antiretroviral treatment was changed from tenofovir/emtricitabine and lopinavir/ritonavir to lamivudine/zidovudine and lopinavir/ritonavir for better CSF penetration. CONCLUSIONS: Individuals with BK virus-related CNS infection may show signs of neurological impairment including seizures, hemiparesis, memory loss, visual and speech disturbance. Since the first report of BK virus associated neurological infection, only 24 cases are described. For treatment, a standard antiviral regimen has not yet been established. However in AIDS patients with BK virus-related encephalitis, immune reconstitution by combined antiretroviral therapy appears to improve the clinical condition. Disclosure: Dr. Chu has nothing to disclose. Dr. Dhungana has nothing to disclose. Dr. Johnson has nothing to disclose. Dr. Woc-Colburn has nothing to disclose. Dr. Kass has nothing to disclose.