What is the progression of HIV infection?

Updated: Jan 02, 2020
  • Author: Robert J Carpenter, DO, FACP; Chief Editor: John Bartlett, MD  more...
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Complex changes occur in the immune system during the acute infection period, including rapid depletion of CD4 cells. Anti-HIV antibodies are produced, and cytotoxic CD8+ lymphocytes destroy HIV-infected cells. Unfortunately, the response is imperfect, and latent reservoirs of HIV infection become established throughout the body.

Chronic HIV infection begins after antibodies to the virus have fully developed and the initial immune response is complete. HIV disease with active virus replication usually progresses during this asymptomatic period, and the rate of disease progression correlates directly with HIV RNA levels. Individuals with high levels of HIV RNA progress to symptomatic HIV disease faster than patients with low levels of HIV RNA.

Some individuals develop symptoms or organ dysfunction during chronic infection due to direct effects of the virus rather than a defect in cell-mediated immunity. Some infected persons who are otherwise asymptomatic develop persistent generalized lymphadenopathy (PGL) during this time. With few exceptions, CD4 cell counts decline progressively during this asymptomatic period, at an average rate of approximately 50 cells/µL/y.

Acquired immunodeficiency syndrome (AIDS) is the condition that results from long-term (chronic) HIV infection and is defined by an absolute CD4 cell count of less than 200 cells/µL and specific opportunistic infections or malignancies. The interval between acute HIV infection and AIDS is highly variable, with a median time of approximately 10 years. In many infected individuals, an opportunistic disease is the first manifestation of HIV infection. When the CD4 cell count falls to below approximately 200 cells/µL, the resulting state of immunodeficiency places the individual at high risk for opportunistic infections and neoplasms (clinically apparent HIV disease).

For other discussions of HIV infection, see HIV Disease, Pediatric HIV Infection, and Antiretroviral Therapy for HIV Infection.

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