immune responses Flashcards
which are the acute phase reactants involved in iron metabolism?
ferritin (increases)
hepcidin (increases)
transferrin (decreases)
pathways of complement
classic - IgG or IgM mediated
alternative - microbe surface molecules
lecthin - mannose/sugar on microbe surface
what does C3b do?
opsonization
what do C3a, C4a, C5a do?
anaphylaxis
C5a also does neutrophil chemotaxis
what do C5b-9 do?
MAC ATTACK!!!!&@^$^#!^!@!@!
what is DAF?
aka CD55
complement cascade inhibitor - prevents auto-activation
DAF deficiency –> lysis of RBCs, PNH
what is C1 esterase inhibitor?
complement cascade inhibitor
deficiency –> hereditary angioedema
** ACE inhibitors CONTRAINDICATED
severe recurrent pyogenic sinus and respiratory infx; increase susceptibility to type III hypersensitivity?
C3 deficiency
susceptibility to recurrent Neisseria bacteremia?
C5-C9 deficiency
IL-1 function?
FEVER
inflammation
recruit WBCs
activates endothelium –> adhesion molecules
IL-6 function?
ACUTE PHASE PROTEINs stimulated
fever
IL-8 function?
neutrophil chemotaxis
clean up on aisle 8!
IL-12 function?
differentiation of TH to TH1
activation of NK cells
TNF-a function?
septic shock
endothelial activation
WBC recruitment
vascular leakage
** cachexia in malignancy
IL-2 function?
stimulates growth of T cells and NK cells
IL-3 function?
supports growth/diff of bone marrow stem cells (GM-CSF-like)
IFN-g function?
made by NK cells
stimulates macrophages
NK cell activation
increase MHC expression and antigen presentation
IL-4 function?
TH2 differentiation
IgE production (and IgG)
B cell growth
IL-5 function?
B cell differentiation
IgA production
eosinophil growth
IL-10 function?
modulates inflammatory response
decreases MHCII and TH1
inhibits macrophages and dendritic cells
what is pyocyanin?
made by PsA
generates ROS to kill competing microbes
what is lactoferrin?
protein in secretory fluids and neutrophils
inhibits microbial growth via iron chelation
T cell surface proteins?
TCR
CD3 (assoc with TCR - signal transduction)
CD28 (binds B7)
CD4/CD8
helper T cell surface proteins?
CD4
CD40L
regulatory T cell surface proteins?
CD4
CD25 (binds IL-2)
FOXP3
B cell surface proteins?
Ig
CD19, CD 20, CD 21 (EBV), CD40 (binds TH cell CD40L)
MHCII
B7 (binds T cell CD28)
macrophage surface proteins?
CD14 (binds LPS/endotoxins) CD40 MHCII B7 receptors for Fc and C3b - phagocytosis
NK cell surface proteins?
CD 16 (binds IgG Fc) CD56 (unique)
hematopoietic cell surface protein?
CD34
classic examples of antigenic variation?
salmonella (2 flagella) borrelia recurrentis N gonorrhea (pilus) flu, HIV, HCV trypanosomes
when do you give preformed antibodies to people?
post-exposure ppx in: tetanus botulinum HBV varicella rabies
anaphylaxis, atopy, IgE, mast cells, basophils, histamine, preformed Ab, delayed response from leukotrienes?
type I hypersensitivity
dx: skin test for IgE
IgM/IgG bind antigen, cellular destruction?
type II hypersensitivity
antibody and complement –> MAC attack
direct and indirect Coombs
serum sickness, arthus reaction?
type III hypersensitivity
antigen-antibody-complement complex –> tissue damage
drug reaction - fever, urticaria, arthralgia, proteinuria, LAN
delayed; T cells make cytokines, macrophage activation, no antibodies?
type IV hypersensitivity
transplant rejection
PPD
contact dermatitis
what is the arthus reaction?
edema, necrosis, complement activation at site of intradermal injection
examples of type I hypersensitivity?
anaphylaxis
allergies
examples of type II hypersensitivity?
AIHA transfusion rxns Goodpasture Graves GBS MG ITP
examples of type III hypersensitivity?
arthus rxn
SLE
PSGN
serum sickness
examples of type IV hypersensitivity?
contact dermatitis
GVH
MS
PPD
antidesmosome/antidesmoglein?
pemphigus vulgaris
anti GAD 65?
DM1
antihemidesmosome?
bullous pemphigoid
anti-smooth muscle?
autoimmune hepatitis
p ANCA?
EGPA (churg Strauss)
microscopic polyangiitis
c ANCA?
Wegeners
BTK defect, recurrent bacterial and enteroviral infx, no LN or tonsils?
X-linked/Bruton’s agammaglobulinemia
absent B cells, decreased Ig
most common 1ary immunodeficiency, often asx, airway/GI infx, autoimmune, atopy?
selective IgA deficiency
defect in B cell differentiation, acquired/inherited, autoimmune, bronchiectasis, lymphoma, sinopulm infx?
CVID
22q11, absent thymus and parathyroids, tetany, viral/fungal infections?
DiGeorge - CATCH22
FISH for 22q11 deletion
decreased TH1 response, mycobacterial and fungal infections, presents after getting BCG vaccine, decreased IFN-g?
IL-12 receptor deficiency
autosomal recessive
STAT3 mtn, TH17 deficiency, coarse facies, abscesses, retained teeth, high IgE, low IFN-g, eczema?
Job syndrome = autosomal dominant hyper-IgE syndrome
noninvasive candida infections of skin and mucous membranes
chronic mucocutaneous candidiasis
T cell dysfunction
FTT, chronic diarrhea, thrush, recurrent infx of all types, absent thymic shadow, germinal centers?
SCID
tx: BM txp
types of SCID?
IL-2R gamma chain - XL
adenosine deaminase deficiency - AR
ataxia, spider angiomas, IgA deficiency, increased AFP?
ataxia teleangiectasia
ATM gene defects –> dsDNA repair impaired
all Ig decreased
lymphopenia, cerebellar atrophy
severe pyogenic infections early in life, opportunistic infections, increased IgM, decreased IgG/A/E?
hyper IgM syndrome
XLR
defective CD40L
thrombocytopenia, recurrent infections, eczema?
Wiskott Aldrich
XLR
mutation in WAS - can’t reorganize actin
** increased risk autoimmune dz, malignancy
recurrent bacterial skin/mucosal infections, absent pus formation, impaired wound healing? umbilical cord takes forever to fall off?
leukocyte adhesion deficiency
AR
defect in CD18 (LFA-1) - impaired migration and chemotaxis
increased neutrophils but absent at infection sites
albino with recurrent pyogenic infections, peripheral neuropathy, infiltrative lymphohistiocytosis?
Chediak Higashi AR defect in LYST (lysosomal gene) giant granules in granuloctyes and platelets pancytopenia
infections by catalase+ organisms?
CGD
XLR
dx: abnormal dihydrorhodamine test, negative nitroblue tetrazolium dye reduction test
mechanism of hyperacute txp rejection?
type II hypersensitivity
complement activation via pre-existing Abs
ischemia/necrosis of grafts
mechanism of acute txp rejection?
weeks to months
cellular - CD8 to donor MHC
humoral - Abs develop post-txp
–> interstitial lymphocytic infiltrate
** prevented/reversed with immunosuppressants
mechanism of chronic txp rejection?
months to years
CD4 –> recipient APCs with donor peptides
arteriosclerosis
sx of GVH
rash jaundice diarrhea HSM usually in BM and liver txp