I: Human Immunodeficiency Virus (HIV) Flashcards
Retrovirus that consists of RNA and Reverse transcriptase
HIV
2 major co-receptors
R5
X4
co-receptor R5 uses _____ binds with Monocyte and T cells
CCR5
co-receptor X4 uses _____ binds with T cells
CXCR4
uses both X4 and R5 as receptors
R5X4
HIV-1 was formerly called
HTLV-III
LAV
ARV
HTLV-III stands for
Human T-cell Lymphotrophic Virus Type III
LAV stands for
Lymphodenopathy-associated Virus
ARV stands for
AIDS-Associated Retrovirus
Type of HIV commonly seen in Europeans and American
HIV-1
Type of HIV predominant in WEST AFRICA
Less pathogenic
Low MOT
HIV-2
MOT of HIV
Sexual Intercourse
Parenteral (infectious blood/fluids)
Perinatal (Mother to child)
Blood component: Capable of transmitting HIV infection
Whole Blood
Packed RBC
Plasma
Leukocytes
Platelets
Cornerstone of screening for HIV
ELISA
Standard treatment for HIV; combination of at least 2 drug classes
HAART
High Active Antiretroviral Therapy
responsible for binding to CD4 receptor of T cell
gp120
first to appear during infection
p24
change of serological test from negative to positive as a result of developing the measurable antibodies in response to infection/immunization.
Seroconversion
Laboratory Test used for detection of HIV
CD4 T cell enumeration
HIV Antibody Detection
p24 Antigen Detection
HIV Nucleic Acid Test
PCR
Laboratory Test for HIV:
Gold standard for CD4 Tcell enumeration
Immunophenotyping and Flow cytometry
Laboratory Test for HIV:
HIV Antibody Detection should be done through (2)
Screening
Confirmatory
Laboratory Test for HIV:
HIV Ab detection: Screening
ELISA
Agglutination
Dot-Blot Test
Laboratory Test for HIV:
HIV Ab detection: Confirmatory
Western blot/Immunoblot
Immunofluorescence
Laboratory Test for HIV:
used to determine viral load
Differentiation of drug resistant strains
HIV Nucleic Acid Test
Laboratory Test for HIV:
preferred test for infant or young children less than 18 months
PCR (might have Ab from mother)
Laboratory Test for HIV:
- Quantitative test for HIV nucleic acid
- The Most sensitive test for diagnosis BEFORE SEROCONVERSION
Viral Load Test
ELISA Generations:
Solid-phase Indirect Immunoassay
Virus lysate of HIV-1 only
1st Generation
ELISA Generations:
Indirect immunoassay uses highly purified RECOMBINANT and SYNTHETIC ANTIGEN of HIV 1 & HIV 2
2nd Generation
ELISA Generations:
Sandwich Immunoassay
HIV antibodies of different Ig classes including IgM
3rd generation
ELISA Generations:
consist of HIV 1 , HIV 2, p24 antigen
4th generation
- Heat Inactivation
- Repeated Thawing and Freezing
- Autoreactive antibodies
- Multiple pregnancies
- Severe Hepatic Disease
- Passive Ig administration
- Recent exposure to vaccine
- Malignancies
False POSITIVE ELISA
- Collection of serum prior SEROCONVERSION
- Immunosuppressive therapy or replacement transfusion
- Hypogammaglobulinemia
- Technical Errors
- Genetically diverse, recombinant strain of HIV
False NEGATIVE ELISA
Secretions that can potentially transmit HIV
Semen
Vaginal Secretions
Blood
Breast Milk
HIV infecting T cells
T tropic (X4)
HIV Infecting Macrophanges and T cells
M tropic (R5)
Precursor protein of p6, p9, p17, p24
p55
cleaved gp120 and gp41 derived from
gp160
ELISA that yields positive result must be
replicated
2 out 3 ELISA result subject to
Confirmatory
How many bands should be exhibited in Western Blot if (+) for HIV
2 out of 3
3 bands tested for Wester blot
gp 120/160
gp41
p24
presence of maternally acquired antibody in newborns makes ELISA
unreliable
HIV - AIDS patient CD4 T cell count
<200 mm3