DLA7/8- HIV-AIDS Infections Flashcards
how is the transition from HIV to AIDS defined
1) Th cell (CD4) count <200 cells/mm^3
OR
2) presence of AIDS defining illness
list the AIDS defining illnesses (hint- 9)
- Candidiasis- invasion past oral thrush
- Kaposi’s sarcoma
- cryptococcosis (extrapulmonary)
- cryptosporidiosis (intestinal)
- CMV retinitis
- MAC (mycobacterium avium complex)
- PML (progressive multifocal leukoencephalopathy)
- HIV wasting syndrome
- HIV related encephalopathy
list the AIDS illnesses related to 200-500 Th cell count
- Candidiasis: oral thrush + involvment of esophagus, trachea, bronchi, lungs
- Kaposi’s Sarcoma (HHV-8)
list the AIDS illnesses related to <200 Th cell count (note don’t include <100)
- PCP
- Histoplasmosis, Coccidioidomycosis: severe and disseminated
- PML (progressive multifocal leukoencephalopathy), JC virus
list the AIDS illnesses related to <100 Th cell count (note don’t include <50)
- Toxoplasmosis: neurological disease
- Cryptosporidiosis: chronic diarrhea
- Cryptococcosis: meningitis + other infections (encephalitis)
list the AIDS illnesses related to <50 Th cell count
- MAC (w/ or w/o dissemination): mycobacterium avium complex
- CMV retinitis
describe the how Th cell count is useful in the Tx for AIDS related illnesses
even if no signs of disease are shown –> Th cell count can be used to determine prophylaxis for certain diseases based on results
describe the basis for IRIS
Immune Reconstruction Inflammatory Syndrome:
- HIV+ Pt has pre-existing infection (+/- Sxs)
- HIV+ Pt is started on HAART
- paradoxical worsening of pre-existing infection b/c of more reactive immune system
-usually self-limiting, especially if pre-existing infection is treated appropriately
describe the change in Th cell count with initiation of HAART
Biphasic:
1) Rapid, 3-6 months: quick, large increase mainly due to inc numbers of memory T cells
2) Slow: gradual inc due to predominately naive Th cells via expansion of T cell clones in thymus
describe the diagnosis of IRIS
(immune reconstruction inflammatory syndrome)
1) worsening of recognized (paradoxical IRIS) or unrecognized (unmasking IRIS)
2) presence of AIDS (Tb is only exception)
3) positive virological and immunological response to HAART
list the many common associated pathogens with IRIS (pre-existing infections)
(immune reconstruction inflammatory syndrome)
- mycobacterium tuberculosis
- mycobacterium avium complex (MAC)
- cryptococcus
- pneumocystis
- HHV-8 (Kaposi’s)
- VZV (Shingles)
- HSV (1/2)
- HepB
- CMV
list the common bacterial infections associated with AIDS
- Tb: mycobacterium tuberculosis
- MAC: mycobacterum avium complex, mycobacterium intracellulare
- Bacillary Angiomatosis: bartonella spp.
(1) is the most common opportunistic infection and leading cause of death in AIDS. (2) is the major concern with (1). (3) and (4) have shown to reduce mortality and morbidity of (1).
1- Tb
2- MDR and XDR Tb — difficult to treat
3- Tb testing / screening
4- better HAART
MAC is caused by (1) bacteria, with (2) as the main description of (1) species. (1) are found in (3) in the environment and is mostly transmitted via (4). It is found in AIDS with a (4) Th cell count.
1- mycobacterium avium, mycobacterium intracellulare
2- acid fast aerobic bacilli
3- ubiquitous (everywhere) including many biofilms —- everyone is exposed
4- inhalation, ingestion (lung/GIT –> blood stream)
5- <50 cells/mm^3
list the 3 clinical results of MAC infection
1) Isolated Pulmonary Disease: rare, only immuno-competent Pts (not in AIDS)
2) ***disseminated disease (advanced HIV)
3) localized disease: MAC lymphadenitis, mainly children
(1) is the main presentation of MAC in HIV/AIDS patients. (2) are the general / systemic symptoms. (3) are the local or organ specific symptoms. (4) is often found to have formed in the affected organs.
1- disseminated MAC disease
2- fever, night sweats, weigh loss, fatigue, anorexia, malaise
3- cough, abdominal pain, diarrhea, anemia, hepatosplenomegaly, lymphadenopathy
4- extensive granulomatous infiltration
Pulmonary MAC:
- mainly affects (1) patients
- (2) are the common symptoms
- (3) are the less frequent symptoms
1- elderly / Pts with pre-existing lung disease
2- (mimic Tb) cough, fatigue, malaise, weakness, dyspnea, chest discomfort, occasional hemoptysis
3- fever, weight loss
Localized MAC:
- mainly affects (1) patients
- (2) relationship to HIV patients
- (3) are the presenting symptoms
1- children
2- presents as IRIS in HIV Pts
3- Lymphadenitis: fever, inflamed tender LNs, leukocytosis (CBC)
MAC diagnosis:
- (1) imaging results
- (2) laboratory / blood results (include what organ was involved based on each result)
1- lung infiltrates, interstitial pattern, hilar/mesenteric lymphadenopathy
2- anemia (BM), elevated transaminases (liver), elevated ALP + LDH (disseminated MAC)
MAC microbiological diagnosis:
- culture isolation from (1) sample
- (2) culture duration
- (3) is main distinguishing technique
1- sputum/bronchial wash, blood, lymph node, tissue aspirate
2- 7-10 days (BACTEC system)
3- DNA probes: distinguish from Tb in culture growth (note avium v intracellulare is difficult to distinguish)
Bacillary Angiomatosis (BA):
- (1) cause- internal / external
- (2) affected sites (indicate most common)
- liver/spleen involvement = (3)
- (4) another important DDx to check for
1- Bartonella spp. (henselae, quintana) — advanced HIV or non-compliant with therapy
2- **skin (unique vascular lesions); bone, respiratory tract, GIT, LNs, CNS
3- bacillary peliosis
4- Kaposi’s sarcoma
BA, cutaneous lesions:
- (1) describe number
- (2) describe forms
- (3) describe progression
1- solitary or multiple (rarely disseminated)
2- papular, nodular, pedunculated, verrucous
3- papules expand –> large pedunculated lesions / nodules that are friable –> erosions and bleeding
describe BA diagnosis
Note- very difficult
- Culture, PCR via tissue/blood samples
- histopathology and staining: tissue samples
describe the ‘other’ bacterial infections associated with HIV/AIDS (not Tb, MAC, BA, hint- 2 types)
Bacterial Pneumonias: mostly Strep. pneumoniae – some H. influenxae, S. aureus, Pseudomoas spp. (depends on HIV stage)
Salmonellosis: atypical Sxs, recurrent episodes, reactive arthritis (Reiter’s syndrome)
list the common viral infections associated with AIDS
- HBV, HCV
- CMV
- PML
(not technically- HHV-8, Kaposi’s)
CMV:
- (1) family, subfamily, and alternate names
- (2) genetic makeup / envelope status
- establishes latent infection in (3) cells
1- herpesviridae; betaherpesvirinae, HHV-5
2- dsDNA, enveloped
3- monocytes, dendritic cells, megakaryocytes, myeloid progenitor cells in BM
CMV:
- (1) presentation in immuno-competent Pts
- (2) presentation in immuno-compromised Pts
1- CMV mononucleosis, congenital infections
2- *retinitis + GI, CNS, respiratory Sxs
CMV retinitis:
- usually occurs with Th cell count of (1)
- (2) are the typical Sxs
- (3) is the typical progression
- (4) is the main microscopic feature
1- <50 cells/mm^3
2- unilateral blurry vision of loss of vision, scotoma (blind spots), floaters, photopsia (flashing lights)
3- full thickness retinal necrosis and edema –> replaced by thin atrophic scar –> retinal detachment –> blindness
4- basophilic intranuclear inclusion bodies = ‘owl’s eyes’ in tissue
PML = (1):
- usually occurs with Th cell count of (2)
- (3) definition
- (4) gross appearance
- (5) radiological appearance
1- progressive multifocal leukoencephalopathy (JC virus)
2- <200 cells/mm^3
3- demyelination of CNS
4- granularity of white matter (resemble MS plaques)
5- hyperintensity of highly myelinated (eg. frontal lobes) areas indicating demyelination
describe relationship between HIV and HBV/HCV
- HIV inc chance of also having HBV, HCV; especially HCV if from IV drug use
- better chance of chronic and more serious infection + risk of liver developments: cirrhosis, liver cancer
- inc risk of liver toxicity from HAART
describe relationship between HIV and HSV-1/2
-HIV inc chance of also having HSV-1/2
- more severe sores, longer healing time, more systemic Sxs (brain damage and blindness)
- possible Shingles from VZV reactivation
-high risk for disseminated, life-threatening disease — exposed in IRIS
describe relationship between HIV and HPV
- aggressive disease
- higher risk of cervical cancer even with low risk HPV serotypes
list the common fungal infections associated with AIDS
- candida, esophagitis
- cryptococcal meningitis
- PCP
list the common parasitic infections associated with AIDS
- CNS toxoplasmosis
- cryptosporidiosis
- visceral leishmaniasis
list the common malignancies associated with AIDS
Kaposi’s sarcoma
Non-Hodgkin’s lymphoma
Candidiasis in HIV:
- (1) presentation in AIDS
- (2) most common causative species
- (3) most useful diagnostic characteristics (hint- 3)
1- esophagitis (white patches)- in addition to classic oral thrush
2- candida albicans
3- budding yeast, pseudohyphae, germ tube test+
Cryptococcosis:
- (1) most common source
- usually occurs with Th cell count of (2)
- (3) presentation in immuno-competent Pts
- (4) presentation in immuno-compromised Pts
1- Cryptococcus Neoformans- soil via bird/bat droppings
2- <100 cells/mm^3
3- primary lung disease / chronic pneumonia
4- meningitis, meningoencephalitis
describe the useful diagnostic characteristics for cryptococcus neoformans
- encapsulated -yeast –> halo appearance around yeast on culture
- narrow base budding yeast
describe the symptoms of cryptococcosis meningitis
- fatigue, fever, malaise
- HA, neck pain/stiffness — other signs of meningitis
- seizure, photophobia, vomiting
Pneumocystis pneumonia:
- (1) causative species with (2) as the unique characteristic
- (3) main mode of transmission
- usually occurs with Th cell count of (4)
1- pneumocystis jirovecii
2- lacks ergosterol in cell walls — has cholesterol
3- inhalation – respiratory tract
4- <200 cell/mm^3
Pneumocystis pneumonia:
- (1) pulmonary Sxs
- (2) extrapulmonary Sxs
- (3) hallmark of PCP
(pneumocystis jirovecii)
1- chronic pneumonia: progressive dyspnea, nonproductive cough, fever for days-wks
2- (<3% of cases) lesions in LNs, spleen, liver, BM
3- interstitial pneumonitis w/ mononuclear infiltrate (plasma cells mostly)
Toxoplasmosis:
- (1) main causative agent
- (2) main mode of transmission
- usually occurs with Th cell count of (3)
- (4) form in immuno-competent Pts
- (5) form in immuno-compromised Pts
1- toxoplasma gondii- intracelluar protozoan parasite
2- cats
3- <100 cells/mm^3
4- asymptomatic
5- encephalitis
Toxoplasma Encephalitis:
- (1) predominate pathogenesis
- (2) Sxs
- (3) Dx
1- almost exclusively reactivation of latent tissue cysts
2- HA, confusion, fever, focal neurological deficits, seizures
3- T cell count (<100), clinical features, poor HAART compliance, T. gondii IgG+, single/multiple ring-enhancing lesions on MRI
Cryptosporidiosis:
- (1) main causative agent
- (2) main mode of transmission
- usually occurs with Th cell count of (3)
- (4) form in immuno-competent Pts
- (5) form in immuno-compromised Pts
1- cryptosporidium parvum- intracellular protozoan parasite
2- ingestion (contaminated food/water)
3- <100 cells/mm^3
4- self-limiting disease
5- severe chronic diarrhea (>1mo)
Cryptosporidiosis:
- (1) Sxs
- (2) complications
- (3) Dx
- (4) Tx
1- severe chronic diarrhea (>1mo)
2- dehydration, malnutrition, acalculous cholecystitis
3- PCR, microscopy, EIA (enzymatic immunoassay)
4- start or boost HAART –> elevated Th cells –> self-limiting disease
Visceral Lishmaniasis:
- (1) main causative agent
- (2) main mode of transmission from (3) geographic areas
1- lishmania donovani, lishmania infantum
2- female phlebotomine sand fly
3- South Asia (Bang., India), Africa (S./Sudan, Eth.), S. America (Brazil)
Visceral Lishmaniasis:
- (1) site of replication
- (2) Sxs
- (3) = darkening of skin seen in South Asia
1- reticuloendothelial system (RES) –> spleen, liver, BM will have high parasite counts
2- malaise, fever, weight loss, hepatosplenomegaly, LUQ pain, severe anemia / pancytopenia, lymphadenopathy, hypoalbuminemia
3- Kala-azar / black fever
