A Genetic Analysis of HIV-1 Envelope Gp160 Sequences Derived from Blood and Brain Samples

A wide spectrum of neurological syndromes are associated with HIV infection. Nearly all AIDS patients have detectable levels of HIV proteins and nucleic acids in the brain, and 30% develop neurological symptoms from this invasion. The mean survival time after diagnosis of neurological complications is six months. Although it has been known for over a decade that HIV-1, rather than opportunistic infections, is the primary agent responsible for the neurological damage, little is known about its neuropathogenesis. HIV-1, like other retroviruses, is characterized by a high degree of viral heterogeneity. This genetic diversity is caused by the infidelity of the viral reverse transcriptase, and is influenced by selective pressures and competition placed on the viral isolates by immunological restraints and different cell types found within tissues.