Uveomeningoencephalitis in a human immunodeficiency virus type 2-seropositive patient

HIV-2 encephalitis: case report and literature review

We report the case of a 59-year-old man who moved from Cape Verde to Massachusetts at the age of 29. He had multiple sexual contacts with female partners in Cape Verde and with West African women in Massachusetts, as well as multiple past indeterminate HIV-1 antibody tests. He presented to our facility with 2-3 months of inappropriate behaviors, memory impairment, weight loss, and night sweats, at which time he was found to have an abnormal enhancing lesion of the corpus collosum on brain magnetic resonance imaging (MRI). Laboratory testing revealed a CD4 count of 63 cells/mm(3), positive HIV-2 Western blot, serum HIV-2 RNA polymerase chain reaction (PCR) of 1160 copies per milliliter and cerebrospinal fluid (CSF) HIV-2 RNA PCR of 2730 copies per milliliter. Brain biopsy demonstrated syncytial giant cells centered around small blood vessels and accompanied by microglia, which correlated with prior pathologic descriptions of HIV-2 encephalitis and with well-described findings of HIV-1 encephalitis. Based on genotype resistance assay results, treatment guidelines, and prior studies validating success with lopinavir-ritonavir, he was treated with tenofovir-emtricitabine and lopinavir-ritonavir, which has led to virologic suppression along with steady neurologic and radiologic improvement, although he continues to have deficits.

HIV type 2 demyelinating encephalomyelitis

A human immunodeficiency virus (HIV) type 2 (HIV-2)-infected African patient developed inflammatory demyelinating lesions of the optic nerves, spinal cord, and brain, which coincided with a decreasing CD4 cell count and with active HIV-2 replication. This case provides evidence that HIV-2 is neurotropic, extends the range of known HIV-2-associated neurological complications, and confirms the overlap between the neurological complications of HIV type 1 and HIV-2 infection.

Productive HIV-2 infection in the brain is restricted to macrophages/microglia

OBJECTIVES

HIV-2 can use a broader range of co-receptors than HIV-1 in vitro, and is less dependent on CD4 for infection. The aim of this study was to detect productive HIV-2 infection in the brain and investigate whether HIV-2 has an expanded tropism for brain cells in vivo, in comparison with HIV-1, which productively infects macrophages/microglia.

DESIGN

Brain samples taken at autopsy from eight patients who died from AIDS, six HIV-2 and two HIV-1/HIV-2 dually seropositive, with HIV encephalitis (HIVE), collected in Abidjan, Côte d'Ivoire in 1991, were examined for the presence and localization of productive HIV-2 infection.

METHODS

Using immunohistochemistry, the presence of HIV-2 p26 in formalin-fixed, wax-embedded brain tissue sections was investigated. Double-staining with glial fibrillary acidic protein (GFAP), CD45- and CD68-specific antibodies was performed to identify infected cell types.

RESULTS

HIV-2 p26 was detected in brain tissue from four of the HIV-2 cases and one of the dually infected individuals. The productively infected cells were either microglia or infiltrating macrophages.

CONCLUSIONS

The productively infected cells in the brains of HIV-2 infected individuals are macrophages/microglia. No evidence was found for productive infection of astrocytes, neurons or oligodendrocytes. Thus, the broader in vitro cell tropism, promiscuous coreceptor usage and relative independence of CD4 by HIV-2 compared to HIV-1 does not broaden its range of target cells in the brain.