HIV encephalitis related to the development of a discordant resistant virus in CNS

Learning from cerebrospinal fluid drug-resistant HIV escape-associated encephalitis: a case report

BACKGROUND

In the era of antiretroviral therapy (ART), central nervous system (CNS) complications in patients with human immunodeficiency virus (HIV) infection are sometimes associated with cerebrospinal fluid (CSF) viral escape. Here, we reported a case of persistent CNS viral escape with recurrent symptomatic encephalitis, which had ultimate stabilization achieved by a combination of ART adjustment and corticosteroids.

CASE PRESENTATION

A 27-year-old man with HIV infection complained of recurrent headaches during the last year. His magnetic resonance imaging (MRI) presented diffused bilateral white matter lesions, and laboratory tests confirmed elevated CSF protein level, lymphocytic pleocytosis, and detectable CSF HIV RNA (774 copies/mL). Plasma HIV RNA was well suppressed with tenofovir, lamivudine, and lopinavir/ritonavir. Prednisone 60 mg once daily was initiated to reduce intracranial inflammation, followed by a good clinical response, with CSF HIV RNA still detectable (31.1 copies/mL). During the gradual tapering of prednisone, his headache relapsed, and booming viral loads were detected in both CSF (4580 copies/mL) and plasma (340 copies/mL) with consistent drug-resistant mutations. Thereupon, prednisone was resumed and the ART regimen was switched to zidovudine, lamivudine, and dolutegravir according to drug resistance tests. Persistent clinical recovery of symptoms, neuroimaging, and laboratory abnormalities were observed in the follow-up visits.

CONCLUSION

CSF and plasma HIV RNA and further drug resistance tests should be monitored in HIV-infected patients with neurologic symptoms, as opportunistic infections or tumors can be ruled out. ART optimization using a sensitive regimen may be crucial for addressing CSF viral escape and the related encephalitis.

What can characterization of cerebrospinal fluid escape populations teach us about viral reservoirs in the central nervous system?

OBJECTIVE

To review the evidence that CSF (cerebrospinal fluid) escape populations are produced by viral reservoirs in the central nervous system (CNS).

DESIGN

CSF escape is a rare phenomenon in which individuals on suppressive ART have well controlled systemic infections with elevated levels of HIV-1 RNA in their CSF. However, the rarity of CSF escape coupled with relatively low CSF viral loads has impeded detailed analyses of these populations. Here, and in a previous study, we performed genetic and phenotypic assessments of CSF escape populations to determine whether CSF escape is produced by CNS reservoirs or by cells trafficking through the CNS.

METHODS

We report HIV-1 viral loads in the CSF and blood plasma of four individuals with CSF escape (one new example and three previously described examples). We performed phylogenetic analyses of the viral env gene to evaluate diversity within the CSF escape populations and performed entry analyses to determine whether Env proteins were adapted to entering macrophage/microglia.

RESULTS

Two individuals had CSF escape produced by CNS reservoirs. In contrast, the remaining two cases were likely because of transient viral production from cells migrating into the CNS and releasing virus.

CONCLUSION

Together our analyses indicate that replication-competent HIV-1 can persist in the CNS during ART, but that not all cases of CSF escape are produced by CNS reservoirs. Our results also suggest that both CD4 T cells and macrophage/microglia can serve as persistent viral reservoirs in the CNS.