Successful Recovery from Meningoencephalitis Associated with Archetype-like JC Virus in a Lung Transplant Recipient: Case Report and Review of the Literature.

Meningoencephalitis due to JC polyomavirus (JCV) is rare and delays in diagnosis could lead to potentially fatal outcomes in immunosuppressed patients. We present a case of an HIV-negative lung transplant recipient who presented with neurological deficits, including aphasia and right-sided weakness. Brain imaging lacked demyelination usually diagnostic of progressive multifocal leukoencephalopathy (PML), the disease most often associated with JC virus, however cerebrospinal fluid (CSF) metagenomic analysis confirmed a high JC viral load, suggestive of JCV-associated meningoencephalitis. After reducing immunosuppression, the patient showed significant neurological improvement within three months and full recovery by 6 months. The JCV genome sequenced from patient's plasma and CSF were identical and resembled the "nonpathogenic" archetype in the non-coding region but shared homology in the coding region with the classically-considered neurotropic strains detected in those with PML. These findings suggest that mutations in the virus's noncoding region are not necessary for neuropathogenesis. We also review other cases of JCV-associated meningitis and encephalitis, which, in contrast to our case, were all fatal. Clinicians should consider JCV testing in immunosuppressed patients with encephalopathy and focal neurological deficits, even in the absence of significant brain radiographic abnormalities.