Immunology Flashcards
Anakinra MOA
IL-1 receptor antagonist
Abatacept MOA
Functions as CTLA4, binds to CD80/86 to co-stimulate and down-regulate T-cells
Top 3 food allergens
Egg, peanut, milk
Type A drug rxns are…
Pharmacologic i.e. related to the action of the drug e.g. diarrhoea
Type B drug hypersensitivities are…
Immunologic
Type 1 Hypersensitivity is
IgE mediated
Type 2 hypersensitivity is…
IgG to specific antigen
Type 3 hypersensitivity is…
IgG immune complex deposition
Type 4 hypersensitivity is
T cell mediated
Three MOAs of delayed hypersensitivity reactions
- Drug is a hapten
- Drug is a prohapten
- Direct p-i
Anaphylaxis 3 definitions
- Skin OR angioedema + breathing OR circulation issues
- Suspected allergen PLUS 2 organ systems involved
- Known allergen and ANY organ
Three mechanisms of anaphylaxis
- IgE dependent
- IgE independent immunologic
- Non-immunologic direct mast cell activation e.g. physical, ETOH, opioids
Most specific test of anaphylaxis
Mast cell tryptase
HAE MOA
C1 esterase inhibitor deficiency
HAE inheritance/ mutation:
AD, SERPING1 mutation
GATA2 def
MonoMAC: monocytopaenia, B and NK cell lymphopaenia; MDS/AML, MAC/viral infections
Complement activating isotypes
IgM>IgG3>IgG1>IgG2
C3b, what is it
Opsonin, all phagocytes have a receptor
C3a and 5a
chemokines, all mast cells have receptors -> degranulate
C5b ->
MAC
What bacteria are most susceptible to MAC?
gram -ves as don’t have thick cell wall
C3 convertase inhibitors:
DAF (CD55) and MCP
MAC inhibitors:
CD59 (MAC-IP) and HRF
4 mechanisms for NK cells to recognise invaders:
Lack of MHC I; Increased activating factors; loss of inhibitory factors; ADCC via Fcgamma receptors
NK cells kill via
Fas-L:Fas; perforin and granzymes
Receptors expressed by mature dendritic cell
CD80/86 and MHCII
On what chromosomes are HLA molecules?
Chromosome 6p
What cytokines induce Th1?
IFN-gamma and IL-12
What cytokines do Th1s produce?
TNF-alpha and IFN-gamma
Th1 gene
Tbet
Cytokine that induces Th2
IL-4
Cytokines produced by Th2
IL-4, IL-5, IL-13
Genes for Th2, there are 2!
GATA3/STAT6
Th17 cytokine inducers:
IL-1, IL-6, IL-23, TGF-beta
Treg cytokine inducers
TGF-beta, IL-10
Treg gene
FOXP3
Tregs express 3 markers on their cell surface, what are they?
CD4, CD25, CTLA4
Cytotoxic T cells won’t become strong memory Cytotoxic T cells unless what is present?
Th1
B cell signal 1:
MHC:TCR
B cell signal 2:
CD40:CD40L
Deficiency of CD40/CD40L =
Hyper IgM syndrome, unable to class switch
T regs help B cells to..
class switch by expressing CD40L
What part of the Ab determines the isotype?
heavy chain
Where does IgA2 live?
mucous membranes
Quantities of each Immunoglobulin:
IgG>IgA>IgM>IgD>IgE
Is IgM high or low affinity/avidity?
Low affinity; but high avidity because has 10 binding sites- pentamer
Which immunoglobulins are high affinity?
IgG, IgA, IgE (all but IgM)
IgG does what with higher affinity?
opsonises, neutralises, activates complement and ADCC
SCID causing mutations
ADA, Common cytokine Gamma-R, RAG
Main abnormality in Di-George
no thymus
Difference between CVID and XLA
XLA won’t have mature B cells on subsets
Rx of CGD
bactrim + antifungals + IFN-gamma + Anakinra -> SCT
2 tests for phagocyte function
NBT + DHR
Two CTLA4 assoc. genetic conditions
CHAI and LATAI
CHAI- CTLA4 happloinsufficiency w. autoimmune infiltration.
LATAI- LRBA deficiency w. Auto-ab, Treg defects, Autoimmunity
CGD most common infections
lymphadenitis, pneumonia, abscesses of skin/viscera
CGD is from an deficiency of what enzyme?
NADPH oxidase
ALPS inheritance/findings
Autoimmune lymphoproliferative syndrome; AD; increased double -ve alpha-beta T cells in peripheral blood on flow; Defect in FAS
IPEX inheritance/ findings
Immune dysreg polyendocrinopathy X-linked; FOX-P3 defect so no Tregs
Autoimmune Polyglandular syndrome Type 1 defect/hallmarks:
AIRE gene; candida, Addison’s hypoparathyroid
Complement activating factors
Properdin, B and C from monocytes
HAE rx options
FFP, plasma derived C1-inhibitor, Icatibant
Icatibant MOA
Bradykinin B2 receptor antagonist
Loss of which inhibitors gives aHUS?
Factor H, I and MCP
Inflammasome 2 signals for initiation
- TLR -> NFkappaBEta -> pro-IL-1 beta
2. DAMPs/PAMPs -> caspases to activate Il-1
CAPS defect/ inheritance/ syndromes
Defect in NLRP3/ AD/ Muckle-wells, NOMID, FCAS
CAPS mechanism
persistently activated DAMPL signalling pathways
Schnitzler’s syndrome
IgM kappa paraprotein; neutrophilic urticaria rash; rx w. anakinra
Opsonins that augment microbial phagocytosis by neutrophils and macrophages; and one that isn’t
C3b, CRP, IgG, MBL; NOT C5a
What innate cell expresses the most varied number of TLR and cytoplasmic receptors?
dendritic cells
Most common gene affected in XL CGD
CYBB
Most common genes in CVID
NFKB1 or 2
When testing for Ab response to vaccine what type of vaccination should be used?
Unconjugated polysaccharide
