Immunology Flashcards
HLA class 1 presents to
CD8 - cytotoxic T cells
HLA class 2 presents to
CD4 - helper T cells
hypersensivity
immune response is exaggerated or inappropriate to harmless environmental antigens
Ab in type 1 hypersensitivity, also called?
IgE
also called allergy and atopy
allergy is a result of
end result of complex interplay of a number of factors - atopy, environment, immune reactivity
pathogenesis of allergy
mast cells + IgE - stimulate mediators to cause secretions, vasodilation, mucosal oedema
diagnosis of allergy
hx , ex, skin prick tests
IgE (RAST test)
type 2 hypersensitivity
IgG.or IgM
self or exogenous stimulator
examples of type 2 self hypersensitivity
graves
myasthenia gravis
goodpastures
examples of type 2 exogenous hypersensitivity
blood transfusion - haemolytic reaction
HDN
hyper acute graft rejection
type 3 hypersensitivity
antibody antigen complex disposition in tissues = immune complex recruits inflammatory cells - tissue damage
two outcomes from hypersensitivity type 3
serum sickness
arthrus reaction
serum sickness?
systemic illness where immune complexes form in the circulation and are deposited in a widespread fashion throughout many tissues
arthrus reaction
a more localised disorder where complexes are actually formed locally in tissues rather being deposited from the blood
e.g. of Hypersensitivity 3
EAA
post strep GN
SLE
type IV hypersensitivity mediated by
T helper cell mediated and its cytokine products IL2 , gamma interferon
type 4 examples
Mantoux test
contact dermatitis
autoimmunity due to
loss of tolerance - therefore autoreactive T and B cells are able to mature
primary defects of innate immunity
chronic granulomatous disease: problem with intracellular killing
leucocyte adhesion def (LAD): neutrophils unable to attach to endothelium
complement deficiencies?
C1-c4?
C3?
C5-C9?
C1-C4: immune complex disease, infection (strep, haemophilia, meningococcus)
C3: recurrent above infections
C5-C9: recurrent neisserial infection
hereditary angioedema
similar presentation to anaphylaxis - but not itchy, or painful
deficiency of C1 inhibitor (control protein)
tx - infusion of C1 inhibitor
SCID?
severe combined immune deficiency
dysfunction with T AND B cells
SCID pc?
well for first 3 months
persistent superficial candida
diarrhoea and failure to thrive
then cross line –> chronic bronchitis, interstitial pneumonitis, bacterial seps
TX for SCID
supportive until suitable bone marrow donor
earlier the better
measurement of complement
functional assessment of pathways with functional assays for genetic deficiencies
allograft?
transfer between genetically non identical members of the same species
xenograft
transfer between species
GVHD?
graft versus host disease
prevention of graft rejection?
ABO matching
Close tissue matching - Class 1 and 2 HLA: especially HLA-A, HLA-B & HLA-DR loci
prophylactic immunosuppressive therapy
GVHD path
principally occurs with bone marrow transplantation - due to:
- presence of functioning immunocompetent donor T cells in the graft
- HLA differences
early signs of GVHD?
erythematous rash on hands and soles of feet - significant diarrhoea
current immunotherapies three main groups
immunosuppressive/immunomodulatory drugs, alternatives to drug therapy and immunoglobulin therapy
examples of immunosuppressive drugs
steroids in combination with Azathioprine and Cyclophosphamide
