Tuberculosis Flashcards
What organism causes tuberculosis? Do they require oxygen?
Mycobacterium - yes, they are obligate aerobes
What is the infectious dose of Tb?
< 10 organisms
Where are Tb organisms contained in the body?
Droplet nuclei land in the alveoli
What cell transports Mycobacterium organisms from lungs to lymph nodes?
Macrophages
What is the skin test called that is used to test if someone has been infected with Tb? What is injected into the skin? What % of false negatives exist?
Mantoux tuberculin skin test - uses PPD (purified protein derivative)
10-20% are false negatives
What % of close contacts of someone infected with Tb also become infected with Tb?
50%!
What infection can accelerate and amplify tuberculosis if the patient gets infected with Tb?
HIV
What corticosteroids are often used as treatment in Tb patients?
Prednisone or dexamethasone
What kind of TB Hematogenous dissemination of large numbers of organisms; lack of T-cell proliferation
Miliary TB
What kind of TB? Only partially effective immune response with many bacilli localized to lung
Pulmonary TB
What kind of TB? Relatively resistant immune response with few bacilli.
Pleural TB
What are Lurie’s rabbits?
colonies of rabbits bred for relative resistance or susceptibility to infection with Mtb
How is Mtb killed inside cells? (5 ways)
- Phagosome-lysosome fusion
- Reactive oxygen species, superoxide
- Reactive nitrogen species, nitric acid
- Cytotoxic T-cells kill infected macrophages
- Apoptosis
What cytokines are essential for granuloma formation?
IL-17 and TNF-alpha
What cytokine is released from monocytes and macrophages stimulated by Mtb?
TNF-alpha
