Hypersensitivity Flashcards
what are the types of hypersensitvity
Type 1 ( IgE mediated) immediate
Type 2 (antigen mediated)
Type 3 ( complex mediated)
Type 4 ( T mediated)
type 1 hypersensitvity what is it generally
IgE-mast cell medaited causing rapid vascular leakage and increase mucosal secretion
mechanism of Type 1 Hypersensitvit
when Th2 cell attach to Allergin it secrets
IL4 and IL13 whcih increase intestinal motility, inc mucus production and make IgE
and secrete IL5 whicih increaase eosinophil activation
TfH cell attach to B cell and secreted IL4 making more IgE and it binds ot FceR1 on Mast cell casign secretion of vasoactive amines, lipid mediators ad cytokinesw
hat does mast cell secrete in HS1
major amines and histamin
protease
prostaglandins
leukotrienes
cytokines to recruit lymphocytes and sustain inflammation
Hay fever
Type 1 HS by inhaled allergins causes sinsuitis and rhinitis
Ingested allergins what will it cause
mast cell degranulation, and histamin secretion and inc peristaliss and vomit and dairrhea
Type 1 HS
Asthma
Type 1 HS due to secertion of leukotrienes from amst cells causing bronchial constriction and airway obstruction
Anaphylaxis
Type 1HS and causes edema in tissue, dec in BP and bronchoconstriction due to mast cell degranulation
due to bee stings, shellfish penicilin and nuts
mechanism of antigen mediated hypersensitvity Type 2 inflammation
medaited by IgG
inflammation: by IgG1 and IgG3 binding to neutrophil and macrophage causing inflammation
ab binding to IgM causing classic complement activation
secertion of ROS and lysosomal enzymes
mechanism of antigen mediated hypersensitvity Type 2 opsonization
ab bind to cells like RBcs, neutrophils and plateletes and phagocytosis them by C3b binding there
perinecous anemia
type 2 HS and it autoab against protiens required for VitB12 absopriton
mysthania gravis
type 2 HS auato ab against ach receptor decreasing neuromuscual transmission
Graves diseas
Ab against TSH receptor causing excessive activtion of thyroid gland
What is mechanism of Immune complex mediated hypersensitvity type 3
immune complees depositing in renal glomruli and joint synovium and causing vasculitis there
it binds because the complex ag is + and BM is -
the Ag Fc region activate complex and bind to FcR on neutrophils causing secretion of ROS and proteases
serum sickness
Type 3 HS
reciving antitoxins from immunized animals causing systmic infalmmation, vasculitis and it can be induced by rabies
Arthus reaction
Type 3 hypersensitvity
subcutanous admiinstration of protien Ag to already immunized person causinf immune complexe at site of injection
causing cutanous vasculitis
SLE
Type 3 HS
ab in immune complex is specfic for sAg or microbial antigen and immune complex of anti DNA ab deposit in blood vessls causing impaired blood flow and systemic infalmmation
poststreptococcal glemrulonephtiis
Type 3HS
after infection antistreptococcal ab form complexes with bacterial ag and deposit in kidney glomurli casuing inflmmation and renal failure
Type. 4 hyperseinsitvity ( T cell mediated)
Th1 cell secrete IFNy activatinig macrophage
Th17 bringing neutorphil to site of infection which will also cause DTH
DTH
T cell and monocyte gather in tisseu causing swellinf and fibirn formation due to increase permeability
Mulitple scleoriss
Type 4 HS
T cell reactive to myelin causing demyelation in CNS
Rheumatoid arthritis
Type 4 HS
DM1
Type 4 HS
impaire glucose metabolsim due to T cell specfic for Beta cell in pancreatic iselts
crohns disease
Type 4 HS
Psoraisis
Type 4 HS
CHornic inflmamtion in skin
contact sesnitvity
Type 4 HS
T cell specfic to skin protiens causinf DTH sepcially to latix, posion Ivy
chornic infection of Tb
Type 4 HS
T cell specfic to micorbial protiens causing chronic granulomatous inflammation
