ABSTRACT
This chapter reviews the primary and secondary effects of HIV infection on the choroid plexus (CPx) and the ependyma and focuses on the potential importance of the choroid plexus as a site through which HIV enters the central nervous system (CNS) and infects the brain. The choroid plexus may be directly infected by HIV. It forms an important part of the immune system of the CNS. Diseases of the choroid plexus can be secondary to the immune suppression that occurs in patients with AIDS. The ependymal lining of the cerebral ventricles is composed of ciliated cuboidal cells that arise from the lining of the primitive neural tube. The majority of circulating immune cells that enter the CNS are located in the choroid plexus and leptomeninges rather than in the brain parenchyma itself. There is an increase in CPx monocytes and T lymphocytes in AIDS patients as compared with nonAIDS, immunocompetent controls.
