L27: HIV/AIDS Flashcards
HIV
human Immunodeficiency Virus
AIDS
acquired immune deficiency syndrome
why acquired?
normal IS - viral infection attacking IS - immune deficiency
MSM, 1981
- 5 men
- diseases fit young men shouldnt have
- how AIDS was discovered (HIV not known yet)
- disease that should only be seen in immunocompromised people (eg. organ transplant)
What did these homosexual men presenting with - illness?
pneumonia, cytomegalovirus, herpes and oral candidiasis
how to treat oral candidiasis
antifungal mouthwash, pastille, medicine
how to treat oral candidiasis
antifungal mouthwash, pastille, medicine
Kaposi’s sarcoma
a rare cancer caused by human herpes virus (HHV8) in people with HIV
toxoplasma gondii
- protozoa
- infects cats, cysts in poo
- brain abscesses
- forms granuloma
AIDS defining illnesses
- pneumocytis carnii
- toxoplasma gondii
- candida albicans
- cryptococcus neoformans (menigitis)
- mycobyterium tuberculosis
when was AIDS recognised?
- french
- 1983-4
first antibodies produced to foreign antigen?
IgM
what antibody is produced after some time
IgG
T-lymphocytes role in HIV
helper (CD4) are infected and killed off by cytotoxic (CD8)
helper lymphocytes
- tell the cells of the IS what to do
- regulate IS, release cytokines as instruction
- talk to CD8, B cells etc to control infection
HIV infects?
helper t cells
Origin of HIV
- retrovirus related to simian immunodeficiency viruses (SIV) which infect african apes
global spread of HIV
Africa - Haiti - US - Europe
Where are the infected CD4 cells found in the body
in the blood, vaginal secretions, ejaculate
How can it be detected
bodily fluids, but not transmitted in other ways that blood than genital secretions
Epidemic spread affected by?
- prevalence of infection
- rate of sexual partner change
- rate of unsafe injecting drug use
HIV strucutre
- enveloped retorvirus
- protein core encasing the genetic material
- two strands of RNA
similar to what viruses?
hepatitis B - enveloped
covid - spike proteins
envelope comes from?
- cytoplasmic membrane of the cell (T cell)
- buds from surfaced of cell, takes with it envelope from cell
What is the spike protein used for in HIV
attachment to CD4 helper cell surface
How is viral RNA copied in the CD4 cell
reverse transcriptase - comes out of virus too
makes DNA copy of RNA structre
DNA genome - transported to nucleus
DNA replication of viral DNA
HIV infection latent or immediate
latent
reverse transcriptase mistakes and significance
- mistake when copying RNA to DNA - virus produced is slightly different than the one that enetered the cell
- generation of very wide range of mutant viruses every day
HIV pathogenesis
- HIV attachment to CD4
- cell activated by exposure to other immunological stimulus
- produce HIV
- CD8 kills CD4 that is producing foreign proteins
HIV production compared to CD4
HIV produced at a faster rate/amount is larger than CD4
- number of CD4 will go down over time after infection
What happens to CD4 lymphocytes over years
- CD4 amount drops
- AIDS illnesses towards the end
initial HIV infection
high level of HIV in blood, lymph nodes swollen, large number of lymphocytes
seropositive
positive to AB to HIV
diagnosis of HIV
- detect AB (ELISA, western blot)
- RNA (PCR)
amount of AB detected by?
ELISA
target for drug treatment
- RNA reverse trasncriptase
- host DNA cutting
- maturation of virus
vaccines for HIV
dont work
man to man risk
1%
man to woman/woman to man risk
0.1%
mother to infant risk
25% at delivery
12% breastfeeding
when did drugs come out
1997
