Hiv,Burkitts Lymphoma And Kaposi Sarcoma Flashcards
What is the causative agent of AIDS?
Human Immunodeficiency Virus (HIV), a non-transforming retrovirus of the Lentivirus family.
What are the two genetically distinct forms of HIV?
HIV-1 and HIV-2, with HIV-1 being more widespread.
What is the primary target of the HIV virus in the immune system?
CD4+ T helper cells, macrophages, and dendritic cells.
Describe the structure of HIV.
HIV is spherical, with an electron-dense core containing p24 capsid protein, RNA, enzymes, a matrix protein (p17), and a lipid envelope with gp120 and gp41 glycoproteins.
What is the role of gp120 in HIV infection?
Gp120 binds to CD4 receptors and chemokine receptors like CXCR4 and CCR5, facilitating viral entry.
What mechanism allows HIV to integrate into the host genome?
Reverse transcription of viral RNA into DNA by reverse transcriptase, followed by integration using integrase.
What triggers the reactivation of latent HIV infection?
Antigenic stimulation and cytokines activate the transcription of viral DNA into RNA.
List the three major modes of HIV transmission.
Sexual contact, parenteral exposure (e.g., contaminated needles, blood transfusion), and vertical transmission (mother-to-child).
Which protein in the HIV structure is targeted in ELISA tests?
P24 capsid protein.
What are the three stages of HIV infection?
Acute infection, chronic asymptomatic phase, and final crisis phase.
Name the opportunistic infections associated with HIV.
Protozoal (Toxoplasmosis), fungal (Candidiasis), bacterial (Mycobacteriosis), and viral (CMV, HSV).
What is Burkitt’s lymphoma?
An aggressive B-cell lymphoma associated with Epstein-Barr Virus (EBV) and often linked to immunodeficiency.
What chromosomal translocation is associated with Burkitt’s lymphoma?
C-MYC oncogene translocation from chromosome 8 to 14, 22, or 2.
Describe the ‘starry sky’ histologic appearance of Burkitt’s lymphoma.
Sheets of lymphoid cells with macrophages containing ingested debris, surrounded by clear space.
What is Kaposi Sarcoma?
A vascular neoplasm caused by Human Herpesvirus-8 (HHV-8).
List the four types of Kaposi Sarcoma.
Classic, endemic (African), transplant-associated, and AIDS-associated KS.
What are the characteristic stages of Kaposi Sarcoma lesions?
Patch stage, raised plaque stage, and nodular stage.
What is the significance of the CCR5 mutation in HIV resistance?
Homozygous CCR5-Δ32 mutation confers resistance to R5-tropic HIV strains.
Which opportunistic infection is most common in AIDS patients?
Pneumocystis jirovecii pneumonia (PCP).
What are the key neurological manifestations of HIV?
AIDS dementia complex, aseptic meningitis, progressive encephalopathy, and peripheral neuropathies.
What is the mechanism of CD4+ T cell depletion in HIV?
Direct viral cytopathic effects, apoptosis, and fusion with uninfected cells to form giant cells.
Name the chemokine receptors critical for HIV entry.
CCR5 (on macrophages) and CXCR4 (on T cells).
What is the relationship between EBV and Burkitt’s lymphoma?
EBV drives B-cell proliferation, which, coupled with immune suppression, leads to Burkitt’s lymphoma.
How is HIV transported to the central nervous system?
Via infected macrophages acting as reservoirs.
