HIV pathology Flashcards
What is activation-induced apoptosis?
Apoptosis caused by chronic activation of uninfected cells by HIV or other infections
Common in AIDS patients
How are immature CD4 T cells lost during HIV infection?
Direct infection of thymic progenitor cells
or
Infection of accessory cells that secrete cytokines needed for CD4 T cell maturation
Where is latent HIV infection located?
CD4 T cells and macrophages in lymph nodes
Protected from antiviral therapy
What is the reason fro poor recall responses to previously encountered antigens?
Selective loss of memory subset of CD4 T cells early in the course of the disease
What is the role of macrophages in HIV infection?
Bud few viruses, store large number of virus particles, allow replication but are resistant to cytopathic effects
Relatively protected from host defenses, serve as reservoirs for infection
How is HIV transmitted to the brain?
Infected monocytes carry the virus to the brain
What is the role of follicular dendritic cells in HIV infection?
Have receptors for Fc portion of immunoglobulins and trap HIV virions coated with anti-HIV antibodies, which are still able to infect CD4+ T cells
What are the effects of HIV infection on B lymphocytes?
Polyclonal activation at germinal center
Bone marrow plasmacytosis
Hypergammaglobulinemia
Circulating immune complexes
Inability to mount AB response to new antigens
What CNS cells are affected by HIV infection?
Macrophages and microglia
What is acute retroviral syndrome?
Typically occurs 3-6 weeks after infection and resolves in 2-4
Nonspecific systemic symptoms
Also rash, cervical adenopathy, diarrhea, vomiting
What are the sites of continuous HIV infection in Chronic infection?
Lymph nodes and spleens
What is the typical length and signs of chronic infection?
7-10 years
Asymptomatic or demonstrate opportunistic infections like candidiasis
What is the most common cancer in AIDS patients?
Kaposi’s sarcoma
