HIV Flashcards
What is AIDS
a) Presence of AIDS indicator condition, irrespective of CD4 AND/OR
b) CD4 <200 /ul irrespective of Clinical symptoms
Is Herpes simplex an AIDS indicator condition or Herpes zoster
Herpes Simplex
Persistent Glandular lymphadenopathy falls in which category of CDC? Category A, B or C
Category A
What Family and Subfamily does HIV belong to
Family- Retrovirus
Subfamily- Lentivirus
Which chimpanzee is Reservoir of HIV
Pan troglodytes troglodytes
Name 3 types of Cells which contain CD4 which are infected by HIV
T lymphocytes
Monocytes /Macrophages
Dendritic cells / Langerhans cells
Which are the two types of Co-receptors to which HIV binds
CXCR4
CCR5
What is APOBEC
APOBEC is family of cellular proteins which inhibis progression of virus after it enters the cells
Which gene and protein of virus acts against this APOBEC
Vif gene which encodes for p23 protein acts against APOBEC to maintain virus infectivity
What is the major difference in terms of Genes between HIV 1 and HIV 2
HIV 1 contains vpu gene
HIV 2 does not have vpu gene instead it has vpx gene
Which gene encodes for p24 (core of virus)
Gag
Which gene encodes for the enzymes Reverese transcriptase and integrase
Pol
Which gene encodes for gp120
Env
Which gene prevents apoptosis of infected CD4 cells
Nef
Env, tat and vpr are pro-apoptotic
Which is the most common virus type, HIV1 or HIV 2
HIV1
Which is the most common group of HIV 1 virus
M group
Which is the most common subtype or clade of HIV 1
M group , C subtype
Also the most common in India
What are CRFs in HIV
CRF are circulating recombinant factors
2 virus subtype join togather in same individual to form a new subtype or CRF which gives then a selective advantage
Which is the most common CRF in Southeast asia
CRF01_AE
Which is the most common mode of transmission of HIV world wide
Sexual route (Heterosexual) transmission
Does hepatitis B immunoglobulin transmit HIV
No
Does FFP transmit HIV
Yes
Which is more infectious, male to female transmission or female to male
Male to Female
Circumcision reduces risk of HIV transmission? TRUE OR FALSE
True
HIV sexual transmission occurs maximum in late phases, TRUE OR FALSE
False
Sexual transmission is more in early phases
OC pills reduces the risk of HIV transmission.. TRUE OR FALSE
False
It increases the risk due to changes in the cervix
What is risk of HIV, Heptitis B and Hepatitis C transmission after occupational skin puncture contaminated with blood
HIV 0.3%
Hepatitis B- 6-30%
Hepatitis C- 1.8%
Saliva is infectious in HIV? TRUE OR FALSE
False
During which period of time, mother to fetus transmission Is maximum in HIV
During delivery (intrapartum)
Aminocentesis increase the risk of Mother to child transmission? TRUE OR FALSE
True
Vitamin A deficiency increase the risk of HIV transmission by breast feeding? TRUE OR FALSE
True
What type of cells are specifically depleted by HIV
T helper cells
What is DC-SIGN and what is its role
DC- SIGN is C type lecithin receptor located on Dendritic cells which helps it to bind with Gp120 of HIV and helps HIV enter the dendritic cells
What is effect of HIV on HLA
HIV dowregulates HLA class I molecule
This helps it to evade immunity
Nef protein helps HIV achieve this
What are the targets of natural antibodies against HIV
The targets are HIV surface proteins Gp120 and Gp41
However HIV has hypervariablity of this enevelope proteins which helps it to evade the antibodies
Monocytes are reservoir for HIV? TRUE OR FALSE
True
Which is the mean duration from initial HIV infection to AIDS in an untreated individual
10 years
What is role of GB-Virus in HIV
Patient infected with GB virus C along with HIV have longer Lifespan then those without the infection
It protects from HIV
Immune activation is preserved in HIV? TRUE OR FALSE
False
Abberent immune activation is one of the hallmarks of HIV
CMV virus upgrades HIV virus? TRUE OR FALSE
True
Other viruses like Herpes simplex, EBV , HHV , HTLV-1 are also known to do this
Malaria increases HIV viral load? TRUE OR FALSE
True
Malaria and TB increase HIV viral load
Which is the most common opportunistic infection in HIV world wide
Tuberculosis (Source: Harrison 18th edition)
Severity of HIV correlates with severity of CD4 apopotosis? TRUE OR FALSE
False
CD4 apoptosis does not correlate with viral level (CD4 count does, but not CD4 apopotosis !)
It reflects the degree of immune activation and not apoptosis
What type of auto- Antibodies are seen in HIV
Anti MHC class II autoantibodies are seen in HIV There is a cross reactivity between MHC Class II and envelope antigens of HIV (gp120, gp41)
Which two infections are commonly worsened by immune reconstitution in HIV (IRIS)
Mycobacterium tuberculosis and Cryptococcus
Which TNF induces and which suppresses HIV
TNF beta- suppresses HIV
TNF alpha- increases HIV
Interferon suppress HIV infection, TRUE OR FALSE
Interferon alpha and beta suppress HIV
Lymphocyte turnover increase in HIV? TRUE OR FALSE
True
CCR5 and CXCR4 are seen in which HIV virus strains
CCR5- R5 virus
CXCR4- X4 virus
Both ? R5X4 virus
What blocks the entry of R5 virus
CCL3, 4, and 5 (RANTES and MIP1) blocks R5 virus
What blocks X4 virus
SDF-1 blocks X4 virus
What type of virus predominates in early phases of HIV tramsmission
R5 virus predominates in early phases
What is the implication if patient has X4 virus
There is rapid progression with X4 virus
Which Clade does not switch from R5 to X4 (CCR5 to CXXR4)
Clade C never switches from R5 to X4
Which infects CNS more, R5 or X4
R5 virus are implicated in affecting CNS
B cells are also affected by HIV? TRUE OR FALSE
False
Untransformed B cells are not affected by HIV
HIV however can activate B cells directly
However in practice, absolute number of B cells are reduced in HIV
Monocytes are reduced in HIV? TRUE OR FALSE
False
Absolute number of Monocytes are normal
However monocytes are infected by HIV as mentioned earlier
NK cells are reduced in HIV? TRUE OR FALSE
False
They are normal in number
Which two types of cells are most affected in brain in HIV
Perivascualr macrophages
Microglial cells
Astrocytes enhances HIV replication in brain.. TRUE OR FALSE
False
Neurons are directly damaged by HIV.. TRUE OR FALSE
False
Neurons and Oligodendrocytes are not affected by HIV
What Chemokine level in CSF correlates with HIV encephalopathy
MCP1 levels in CSF correlates with HIV encephalopathy
What is importance of Apo E4 in HIV
Individuals with Apo E4 are at higher risk of HIV encephopathy and Peripheral neuropathy
What type of cell predominate in Kaposi?s sarcoma
Spindle cells
Kapsosi?s sarcoma is associated with which virus
Human herpes virus 8
Antibodies to HIV appear in what time
In 6 weeks (22 days)
First antibodies are against which protein
Gag proteins ? esp p24, p17 and p55
LAB DETECTION OF HIV
_____
By which method can you detect HIV earliest
Nucelic acid testing (Source: Harrison 18th edition)
Tests HIV within 12 days of infection
What are the window periods for a) antibody b) p24 c) NAT
Antibody- 6 weeks (22 days)
P24- 16 days
NAT- 12 days
Which method is the best screening test for HIV
ELIS A is the best screening test
It has 99.5% sensitivity
What is 4th generation ELISA
It combines HIV Antibody ELISA with p24 antigen testing
Which is the best confirmatory test for HIV
Western Blot
What is FDA criteria for Positive Western blot
2 out of 3 antigens must be positive ? p24, gp120, gp41
what is role of p24 capture assay
It has role in detection of acute HIV syndrome
How many copies of HIV virus are required for detection by commercially available HIV RNA Tests
40-80 copies/ml
At what CD4 emperically is ART considered
CD4 <350 /ul
At CD4 <50 which opportunistic infections occur
MAC
CMV
When is PCP prophylaxis started
CD4 <200
CD of 200 correletes with CD4 percentage of
15%
effective therapy for HIV is when HIV RNA falls to _____
<50 copies
When is HIV trophic testing done
It is done for detecting CCR5 when drug Miraviroc is started
It is effect only if patient has CCR5
What is role of beta2 microgloblin and IgA levels in HIV
They are markers of disease activity in HIV
