T4 - L4 immunodeficiency Flashcards
(62 cards)
why does the immune system need to carry out self-regulation?
important to minimise host damage
features of the innate immune system?
- general/recognises broad classes e.g. bacteria
- rapid onset
- response doesn’t change with repeated exposure
- no memory (same response each time)
features of the adaptive immune system?
- antigen specific
- slower response
- more potent response
- memory
what is immunodeficiency?
the immune system is not effective enough to protect the body against infection
what is primary immunodeficiency?
Inherent defect within the immune system- usually genetic.
rare
what is secondary immunodeficiency?
Immune system affected due to external causes
[e.g. burns, massive cut]
what are causes of secondary immunodeficiency?
- break down of physical barriers
- protein loss
- malignancy
- drugs
- infection
how can protein loss cause secondary immunodeficiency?
d unable to produce the Ab needed
for the infection
how can lymphoma cause secondary immunodeficiency?
- cancer of lymphocyte s
- expands in the
bone marrow, limiting the space for other immune system parts to develop
how can steroids cause secondary immunodeficiency?
- Steroids work by supressing the immune system
- Recurrent courses of steroid can cause immunodeficiency
how can DMARDS cause secondary immunodeficiency?
(Disease-modifying anti-rheumatic drugs)
- Work by suppressing the immune system
how can Rituximab cause secondary immunodeficiency?
- Rituximab works against B-cells
- Clearing B-cells causes no antibody production
- Excessive use could cause immunodeficiency
how can Myelosuppressive cause secondary immunodeficiency?
Myelosuppressive works by suppressing the bone marrow where the
immune system is generated
which drugs can cause secondary immunodeficiency?
Steroids, DMARDS, Rituximab, anti-convultants, myelosuppressive
Phagocytes including neutrophils and macrophages are capable of engulfing and absorbing bacteria. Which phagocyte out of the two is short-lived?
[Neutrophils are short lived (hours)]
[Macrophages are long lived (days, weeks)]
what do lysosomes produce during phagocytosis in order to kill pathogens?
hypochlorous acid (i.e. bleach)
how do pathogens know whether an antigen is self or foreign?
Pathogen recognition receptors (PRRs) - recognise conserved pathogen associated molecular patterns (PAMPs) which are unique to each pathogen
- phagocytes have PRRs for PAMPs
what is pathogen associated molecular patterns (PAMPs)?
[PAMPs are things found in most or a group of bacteria, which differentiate them
from the human’s cells]
- unique to each pathogen
give an examples of a common PAMPs?
Lipopolysaccharide
flagellin
what PRR recognises the PAMP Lipopolysaccharide?
Toll Like Receptor 4 (TLR 4)
what PRR recognises the PAMP flagellin?
TLR5
what PRR recognises the viral RNA?
TLR3
what happens when a phagocyte detects a pathogen via a PRR?
Cascade of events → production of inflammatory
cytokines
MyD88 and IRAK4 are involved in this cascade
Once a phagocyte has recognised a PAMP via a PRR, what two proteins are involved in the following cascade?
MyD88 and IRAK4
