Chapter 4 - HIV Dynamics: Lessons from the use of antiretrovirals

Abstract

Human Immunodeficiency Virus (HIV) is the cause of AIDS and patients with higher plasma levels of HIV tend to develop AIDS more rapidly than those with lower levels. The process by which HIV causes AIDS is known to be largely one of reducing numbers of CD4 lymphocytes, it is most often assumed that this is due to infection of CD4 lymphocytes by HIV, resulting in cell death; however, questions remain about exactly how HIV causes CD4 cell depletion. Treatment of HIV infection with antiretroviraldrugs involves blocking virus replication, so detailed observations in people treated with powerful antiretrovirals can inform us about the role of viral replication in HIV pathogenesis and the dynamics of this process. This chapter outlines the main findings from such studies and discusses some of the implications both for HIV pathogenesis and, more immediately, for understanding how to treat patients more effectively. The prospects for the majority of HIV-infected people worldwide who have no access to antiretroviral drugs, however, remain poor. The hope must be that the increased understanding of HIV infection, which new therapies have provided, may lead to a greater understanding of natural constraints on HIV replication and hence, eventually, to a prophylactic vaccine.