Immunology Flashcards
(50 cards)
which cytokines stimulate CRP production
IL-1 and Il-6
deficiency of which complement component is associated with most severe pyogenic infections
C3
Role fo C3B
opsonisation
Role C3a and C5a
anaphylotoxins- generate chemotaxic gradients; mediate phagocyte migration to area
Role of C5-C9
membrane attack complex
Osmotic lysis of microbe
most common complement deficiency
C2
which complement defiicnecy most associated with SLE
C1
which complement deficinecy is most associated with Nesseria infections
C5-C9
what do CH50 and AH50 test for
activity of classical and alternative complement pathways respectively
Drug reaction with eosinophilia and systemic symptoms (DRESS)
severe adverse drug reaction, up to 2-8 weeks after offending drug
T cell mediated hypersensitivity (type 4)
Usually carbamazepine, phenytoin, lamotrigine, allopurinol, vanc, sulfonamide abx
Characterized by:
-extensive skin rash, mucosal involvement in 50%, usually rash very widespread
- fever
-lymphadenopathy
- eosinophilia
- leucoytosis
neutrophilia
- liver injury with abn LFTs
Rx: if severe: glucocorticoids
GVHD
GVHD occurs when lymphocytes from donated blood are either not recognised by the patient or the patient’s immune system is unable to destroy them. The skin, bone marrow, and gastrointestinal track are most often affected. It occurs 4-30 days after transfusion but usually occurs in the second week post transfusion. It is rare and difficult to treat but can be prevented by the use of irradiated blood products.
Children with immunodeficiency (either primary or secondary to chemotherapy), haematological malignancy or haematopoeic cell transplantation, and premature low birth weight babies are at risk. Children in these groups should receive irradiated blood.
Biopsy: satellite dyskeratosis
Presents with fever, rash, diarrhoea, hyperbilirubinemia, cholangitis , deranged LFTs
difference between TREC and KREC
TREC is a by-product of the T-cell receptor gene recombination- used for SCID, di george, CHARGE, ataxia telangiectasia
KREC is a by-product of the B-cell receptor recombination- used for XLA
T cell development
BM–> thymus for t cell university
Initially double negative
Then double positive - CD4+CD8+
Positive selection- recognise MHC I or II (only survive if bind moderately)
Negative selection- recognise self antigens presented on MHC but dont bind too strongly (or this would cause autoimmunity)
Class depends if they recognise antigen on MHC1 (become CD8) or MHC2 (become CD4)
Then once they are either CD4 or CD8 they leave the thymus as naive T cells and go into the lymph nodes to wait for antigen presenting cells
T helper cell subsets
which cytokine causes T cell proliferation
Il-2
which cell type is IL-2 mainly secreted by ?
CD4 Th cells
what is the immunophenotype of most common type of SCID
T-B+NK-
(x linked, IL2Rg mutation encoding IL-2 receptor gamma chain)
what does IL-2 do?
Produced by CD4 Th cells
Promotes T cell proliferation
Differentiation of T cells into regulatory T cells and memory T cells
Stimulates naive CD4 T cell differentiation into Th1 and Th2 cells , reduces differentiation into Th17
Increases cell killing activity of NK cells and cytotoxic T cells
which 2 immunoglobulins can fix complement
IgM, IgG
what cell types do IgE bind to?
mast cells and basophils
DDx hypogammaglobulinemia
Excessive loss- A1AT ( losing in gut), nephrotic syndrome, intestinal lymphangiectasia
BUT even if losing IgG, unlikely to be able to lose IgM as such a big molecule
why is pneumovax 23 not a very effective vaccine?
polysaccharide vaccine
T cell independant
Mainly IgM produced
Relatively short lived plasma cells
there is a particularly poor polysaccharide response before 2 years
B cell maturation
Th2 cells release which cytokines
Il-4, Il-5, Il-13
