Dr. Karatzios -- HIV Flashcards
Predominant mode of adult acquisition of HIV
Heterosexual intercourse
Predominent mode of childhood acquisition of HIV
Perinatal exposure
6 highly endemic areas for HIV
- Sub-Saharan Africa
- Southeast Asia (Thailand)
- India
- Haiti
- China
- Russia
How HIV enters cells (3 points)
- HIV viral envelope protein (gp120)
- Human T cell receptor
- Human co-receptors (CCR5 or CXCR4 or both)
6 cells that HIV infects
- CD4+ T lymphocytes
- Dendritic cells (skin, lymph nodes, brain)
- Macrophages
- CD8+ T lymphocytes
- NKC
- Natural killer T cells (viral reservoir)
3 systems in which HIV lives
- Lymphoid organs
- CNS
- Genitourinary system
3 lymphoid organs in which HIV can live
- Peripheral lymph nodes
- GI lymph nodes
- Bone marrow
Method of transmission of HIV living in GI lymph nodes
Neonatal
How does HIV enter the CNS?
HIV Tat protein disrupts the BBB –> Microglial and dendritic cells
2 reservoirs of HIV replication
- CNS
- Genitourinary system
3 parts of the genitourinary system in which HIV can live
- Semen
- Renal epithelium
- Marcophages and lymphocytes in cervix
How does HIV infect semen?
HIV crosses the blood-testis barrier
Why is there a high rate of genomic mutation in HIV?
Reverse transcriptase is extremely error-prone
2 types of genomic mutations that HIV may undergo?
- Spontaneous mutations over time
- Drug-driven mutations
2 potential outcomes of spontaneous HIV mutations
- Many are silent/no-effect
- Some confer resistance to medications
Compare wild type HIV to mutated HIV
- Highly mutated = “less fit”
- Wild type = easily transmissible and replicates more efficiently
When do mutants overtake wild type HIV?
- If medications are failing –> mutants accumulate
- Held in reserve and overtake wild type once medications restarted
When does wild type HIV overtake mutants?
Once medications are stopped
Effect of initial viremia from HIV
Infection of lymph nodes
Effect of secondary viremia from HIV
Mononucleosis-like illness
2 events occurring during the window period between initial and secondary viremia
- Silent viral replication in lymph nodes
- Little or no HIV antibodies
Length of window period between initial and secondary viremia
Up to 3 months
7 symptoms of acute HIV syndrome
Mononucleosis-like illness
- Fever
- Malaise
- Non-exudative pharyngitis
- Maculpapular rash (50%)
- Myalgias
- Headache
- GI distress
5 signs of acute HIV syndrome
Mononucleosis-like illness
- Generalized lymphadenopathy
- Hepatosplenomegaly
- Oral or vaginal thrush
- Lymphopenia THEN acute lymphocytosis
Lab findings of acute HIV syndrome
- HIV antibody negative
- PCR and antigen positive
Timeline of acute HIV syndrome
- 1 - 6 weeks after infection
- Lasts up to 3 weeks
- Spontaneous resolution
- –> Window period
Main cell type destroyed by HIV
CD4+ T cells
3 ways CD4+ T cells are destroyed
Severe immune suppression by age (in No/mm3)
- <12 months = <750
- 1 - 5 years = <500
- >6 years = <200
Describe the natural history of HIV disease
Use of HIV serology
Screening and confirmatory test in humans >18 months age
Use of HIV PCR
Screening and confirmatory test in humans < 18 months age
How to determine viral copy number
- Viral RNA numbers expressed as number of copies/mL blood or log:
- log 2 = 100 copies/mL
- log 3 = 1000 copies/mL
- < log 1.6 = <40 copies/mL = undetectable
4 infections associated with HIV disease
- Sinopulmonary infections
- Salmonellosis
- Meningitis
- Candidiasis
Cardiac problem associated with HIV
Cardiomyopathy
3 growth and sexual development issues related to HIV
- Delayed
- Decrease in testosterone/libido
- Osteoporosis
3 neurological issues related to HIV
- Cognitive delay
- Encephalopathy
- Dementia
Renal problem associated with HIV
HIV nephropathy
2 psychiatric issues related to HIV
- Depression
- ADHD
Proportion of AIDS patients with esophageal disease
1/3
6 typical symptoms of esophageal disease in HIV patients
- Dysphagia
- Odynophagia
- Retrosternal pain
- Nausea
- Anorexia
- Weight loss
NOTE: Usually indolent onset
2 causes of dysphagia and odynophagia in AIDS patient
- Esophageal inflammation
- Ulceration
Likely cause of HIV-associated idiopathic esophageal ulcers
HIV seen in lymphocytes and lamina propria
Biopsy findings of herpes virus esophagitis
Multinucleated giant cells
Which other kind of esophagitis does HIV-associated idiopathic esophageal ulcers resemble?
CMV esophagitis
- Shallow ulcers
- Inclusion bodies on biopsy
3 infectious oral lesions associated with AIDS
- Herpes simplex
- Oral hairy leukoplakia
- EBV-related
- Non-painful
- Oral candidiasis (usually painful)
Oral neoplastic lesion associated with HIV/AIDS
Kaposi’s sarcoma
Effect of HBV in HIV/AIDS (3)
- Spontaneous reactivation seen in AIDS
- 19x more likely to die if HIV/HBV co-infected
- HBV does not influence HIV progression, however
3 causes of death in HIV/HBV co-infection
- Cirrhosis
- Live failure
- Carcinoma
Effect of HCV in HIV/AIDS
- 94x higher risk of mortality
- HCV may affect progression of HIV
NOTE: All HIV+ patients should be screened for HCV
3 pharmacological causes of hepatitis in HIV/AIDS patients
- Protease inhibitors
- NNRTI
- Antimycobacterial drugs
Protease inhibitor that can cause hepatitis and steatosis in HIV patients
Ritonavir