Tuberculosis Flashcards
Mycobacterium tuberculosis is a facultative intracellular pathogen that causes chronic pneumonia; it is transmitted via _
Mycobacterium tuberculosis is a facultative intracellular pathogen that causes chronic pneumonia; it is transmitted via aerosols
(T/F) Of individuals exposed, about 70% of individuals will be able to eliminate the pathogen
True; Of individuals exposed, about 70% of individuals will be able to eliminate the pathogen
* It is an opportunistic pathogen
The 30% of individuals exposed to TB will have a primary infection characterized by _
The 30% of individuals exposed to TB will have a primary infection characterized by mild symptoms, ghon complex
Primary TB involves caseating necrosis in the _ lobe and _ lymph node
Primary TB involves caseating necrosis in the lower lung lobe and hilar lymph nodes
Most individuals with primary TB will next go into a _ phase
Most individuals with primary TB will next go into a latent infection phase
* Primary phase: macrophages have phagocytosed the bacteria; bacteria grew intracellularly
* Latent phase: granuloma formation walls off infection
TB has a virulence factor called _ that inhibits _ and allows the bacteria to replicate inside the phagosome of the macrophages
TB has a virulence factor called sulfatides that inhibit phagosome-lysosomal fusion and allow the bacteria to replicate inside the phagosome of the macrophages
Macrophages recognize the PAMPs and release cytokines such as _
Macrophages recognize the PAMPs and release cytokines such as IL-1, IL-6, TNF-alpha
_ is the cytokine responsible for causing aggregation of macrophages and walling off the infection
TNF-alpha is the cytokine responsible for causing aggregation of macrophages and walling off the infection
Both _ cells and cord factor are releasing TNF-alpha
Both macrophages and cord factor are releasing TNF-alpha
Fibrocaseous cavitary lesions are associated with _ stage of TB
Fibrocaseous cavitary lesions are associated with reactivated TB
In a minority of patients, they are not able to wall of the primary infection and go into _
In a minority of patients, they are not able to wall of the primary infection and go into progressive primary TB
* Immune system fails to control
* Bateria replicating in the macrophage burst out and release the bacteria
* Granulomas enlarg and bacteria is draining into hilar lymph (ghon complex)
If progressive primary TB travels into the blood, we can see _ stage
If progressive primary TB travels into the blood, we can see miliary TB
Classic symtoms of TB are those seen in reactivation like _
Classic symtoms of TB are those seen in reactivation like fever, night sweats, fatigue, productive cough, blood-tinged sputum
During reactivation, the enlarged granulomas can liquefy in the center (central necrosis) causing _
During reactivation, the enlarged granulomas can liquefy in the center (central necrosis) causing lung cavities with replicating bacteria –> highly infectious
Explain the steps of the initial MTB immune response
- Macrophages have TLR that recognize the PAMPs
- Macrophages secrete IL-12
- IL-12 activates Th1 cells
- The T cells secrete IFN-gamma that activate the macrophages
- Macrophages secrete TNF-alpha
- Granuloma formation controls the infection
Granulomas are formed by macrophages, T cells, and multi-nucleated _ cells
Granulomas are formed by macrophages, T cells, and multi-nucleated Langhan cells
Isoniazid works by inhibiting _
Isoniazid works by inhibiting mycolic acid synthesis
* Specifically targeting the InhA enzyme
Rifampin is a TB drug that works by inhibiting _
Rifampin is a TB drug that works by inhibiting mRNA synthesis
* Blocks RNA polymerase
The P drug in RIPE stands for _ ; its mechanism is unknown
The P drug in RIPE stands for pyrazinamide ; its mechanism is unknown
Ethambutol is a TB drug that works by inhibiting _ enzyme
Ethambutol is a TB drug that works by inhibiting arabinosyl transferase
* It inhibits arabinoglycan synthesis
* This is a component of the cell wall
The most classic drug regimen for treating latent TB is the combination of _ + _
The most classic drug regimen for treating latent TB is the combination of rifampin + isoniazid
When treating latent TB, rifampin and isoniazid must be combined for _ months or Rifampin alone for _ months, isoniazid alone for _ months
When treating latent TB, rifampin and isoniazid must be combined for 3 months or Rifampin alone for 4 months or Isoniazid alone for 9 months
For active TB we most commonly use _ drugs for the first 2 months, followed by _ for 6 months
For active TB we most commonly use all 4 RIPE drugs for the first 2 months, followed by 2-3 RIPE drugs for 6 months
* Alternatively we can use 9 months of Rifampin + Isoniazid
To treat drug resistant TB we must use _ drugs for the first 8 months followed by _ for the following months
To treat drug resistant TB we must use 5 drugs for the first 8 months followed by 3-4 drugs for the following 12 months
_ is a TB drug that can turn the skin, urine, feces, saliva, or tears orange/yellow
Rifampin is a TB drug that can turn the skin, urine, feces, saliva, or tears orange/yellow
Rifampin has _ effect on CYP 450 enzymes
Rifampin induces CYP450
* Means that it will make other drugs less effective
* Specifically problematic for HIV patients because RT inhibitors and protease inhibitors will be less effective
