Immunology Flashcards
explain 2 types of acute transplant rejection
cellular - CD8+ T cells against graft MHC I (type 4 HS)
humoral - similar to hyperacute but antibodies develop after transplant
vasculitis of graft vessels with dense lymphocytic infiltrate
what does Th2 cell secrete?
IL-4/5/6/10/13
lymph drainage to:
internal iliac
lower rectum to pectinate line.
bladder
uppper 1/3 vagina
cervix and prostate
bevacizumab
target and indication
VEGF
CRC, RCC, NSCLC
what are the 4 TNF-alpha monoclonals?
adalimumab, certolizumab, golimumab, infliximab
what does Th1 activate?
macrophages and cytotoxic T cells
infection in complement deficiency?
encapsulated bacteria in early (C1-4) deficiency
Neisseria sepsis in C5-9 deficiency
what markers identify T reg cells?
CD3, CD4, CD25 and FOXP3
function of IFN-gamma
from Th1 cells, stimulates macrophages to do phagocytosis/killing
inhibits Th2
what factor is released from macrophages that stimulates T helper cell differentiation?
what type of Th cell?
IL-12
Th1, which then secretes IFN-gamma that activates more macrophages
post transfusion
1 hour, evidence of shock and haemolysis; flank pain
diagnosis, type of reaction, pathogenesis
acute haemolytic transfusion reaction
type 2
antibodies against donor RBC proteins
(ABO blood group incompatability - intravascular haemolysis; any other RBC protein - extravascular haemolysis)
azathioprine
mechanism, indication, side effects
extra consideration
precursor to 6-mercaptopurine; blocks PRPP amidotransferase and purine synthesis. inhibits lymphocyte proliferation
RA, crohn’s, glomerulonephritis
pancytopenia; toxicity increased by allopurinol as 6-MP degraded by xanthine oxidase
in T cell maturation both positive and negative selection occurs in the thymus.
what process occurs in what anatomic zone of the thymus?
positive selection happens first in cortex
negative selection follows in medulla
cells go from out to in, then leave via central reticular network into the circulation
what are 4 consequences of splenectomy illustrated on FBC/blood smear?
- Howel-Jolly bodies (nuclear remnants)
- Target cells (sagging cell membrane)
- thrombocytosis
- lymphocytosis
BTK deficiency is what disease?
bruton X-linked agammaglobulinaemia
what proteins are negative (downregulated) actue phase reactants?
albumin - save the amino acids for producing positive ACRs
transferrin - internalised by macrophages to reduce iron scavenging
INF-beta indication
multiple sclerosis
anti-beta2 glycoprotein antibody
disease?
anti-phospholipid antibody syndrome
omalizumab
mechanism and indication
IgE blocker
refractory allergic asthma
what is the mechanism for susceptability to encapsulated organisms with splenic dysfunction?
decreased IgM, decreases complement activation, decreased C3b opsonization
what are 4 types of transplant rejection?
hyperacute (minutes)
acute (weeks to months)
chronic (months to years)
GvHD (variable)
parasitic infection in B cell deficiency
Giardia lambia, because there is no IgA
function IL 12
Th1 differentiation
what are the steps needed for B cell activation by T cells?
B cell presents antigen on MHC II, binds TCR
CD40 binds CD40L on T cell
T cell releases cytokines promoting class switching, affinity maturation and antibody production
post transfusion
1 hour, urticaria, itching, fever, wheeze, respiratory difficulty
diagnosis, type of hypersensitivity
pathogenesis
consideration for special group of patients
allergic/anaphylactic reaction
type 1 hypersensitivity
mast cell degranulation against plasma proteins.
IgA deficient patients must have IgA deplete blood
what is caused by DAF deficiency?
paroxysmal nocturnal haemoglobinuria
complement-mediated lysis of RBCs
function of TNF-alpha
endothelium activation; leak and WBC recruitment
association with DR5
pernicious anaemia
hashimoto thyroiditis
what signals activate NK cells to kill a target cell?
lack of MHC I
non-specific activation signal from target cell
CD16 binding to Fc region of antibody (cell-mediated antibody-dependent toxicity)
viral infections in T cell deficiency
- infectious mono - EBV and CMV
- JC virus
- VZV
fungal infections in T cell deficiency
candida, pneumocystis jirovecii , cryptococcus
nitroblue tetrazolium test fails to turn blue…
chronic granulomatous disease
lymph drainage to:
inferior mesenteric
colon from splenic flexure to rectum
diagnosis?
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giant granules in platelets and granulocytes
Chediak Hiagshi syndrome
what is the rheumatoid factor?
IgM antibody against IgG
where are T cells in the spleen?
periarteriolar lymphatic sheath (PALS)
thymoma is associated with which conditions?
myasthenia gravis
superior vena cava syndrome
what is the macrophage receptor for PAMPs?
CD14
decrease T cell receptor excision circles (TRECs) suggests what?
SCID
bortezomib
target and indication?
26S proteasome blocker
promotes apoptosis in multiple myeloma
DQ2/DQ8
coeliac
how is an antigen loaded onto MHC I?
through ‘transporter assoicated with antigen processing’ (TAP) bound on RER
cytokines that activate NK cells
IL-2, IL-12, IFN-alpha, IFN-beta
(2, 12, a, b)
post transfusion
1 hour fever, headache, chills, flushing
type of reaction, pathogenesis
febrile non-haemolytic transfusion reaction
type 2
antibodies against HLA antigens and WBCs
IFN alpha indication
chronic hepatitis C and B
kaposi sarcoma, MM, hairy cell leukamia
condyloma acuminata
RCC
DR2 (4)
MS, hey fever, SLE, goodpasture
explain both pneumococcal vaccines
polysaccharide - protects against more (23) subtypes of strep pneumo. less immunogenic, fades after 5 years. Not immunogenic in children < 2 y/o, poor humoural immunity
conjugate - 13-valent bound to diptheria toxoid. T and B cell recruitment. higher and longer-lasting Ab levels. IgA produced so less mucosal carry = herd immunity
ezcema, thrombocytopenia, recurrent infections…
diagnosis?
Wiskcott-Aldrich syndrome
WA:TER
denosumab
mechanism and indication
RANKL blocker
osteoporosis
hard and fast rule –
B cell/T cell deficiency susceptable to which organisms?
B cell - bacteria
T cell - fungal/viral
lymph drainage to:
celiac (5)
liver, stomach, spleen, pancreas, upper duodenum
lymph drainage to:
cervical nodes
head and neck
function of IL-5
induces B cells & eosinophils
class switching to IgA
treatment for IL-12 receptor deficiency?
why does this work?
IFN-gamma
IFN-gamma and IL-12 are the cytokines responsible of the maturation of Th0 cells into Th1 cells. If IL-12 signalling is deficienct it can be overcome with IFN-gamma supplimentation
abciximab
function and indication
GpIIb/IIIa blocker
thrombosis prophylaxis during percutaneous coronary intervention
function IL 6
fever and acute phase reactants
antimitochondrial antibody
disease?
PBC
oprelvekin function and indication?
IL-11 analogue, thrombopoesis
thrombocytopenia
lymph drainage to:
hilar nodes
lungs
anti-TPO antibody
what disease?
hashimoto thyroiditis
defect in CD18 is what disease?
findings on blood smear?
Leukocyte adhesion deficiency (type 1)
CD18 a.k.a. LFA-1 integrin
impaired chemotaxis and migration
many leukocytes in peripheral blood but none at site of infection
NK cells use what as effector enzymes?
perforins and granzyme
attacks viral infected cells and tumour cells
bacterial infection with B cell deficiency
Please SHINE my SKiS
pseudomonas, strep pneumo, HiB, N meningitidis, E Coli, Salmonella, Klebs, GBS
association HLA B8 (3)
addison disease, myasthenia gravis, Graves disease
what type of bacteria are mainly attacked by complement/MAC?
gram negative
which antibody has the lowest serum concentration?
IgE
what is the function of a seconary lymphoid organs?
allow immune cells to interact with antigens
what is the cause of hereditary angioedema?
what is the mechanism?
diagnosis using blood test? contraindication in this condition?
C1 esterase inhibitor deficiency
unregulated activation of kallikrien, activation of bradykinin
characterised by low C4 levels
ACE inhibitors
what is the inheritance of hyper IgM syndrome?
X linked recessive
decreased number of plasma cells in blood and decreased numbers of Ig, but some present across all classes
diagnosis?
common variable immunodeficiency
high risk of bronchiectasis, autoimmunity, lymphoma
what are the complement fragments that cause anaphylaxis?
C3a C4a C5a
functio of IL-2
growth of all T cells and NK cells
etanercept
mechanism?
decoy receptor for TNF-alpha
basiliximab
mechanism, indication, side effects
blocks IL-2R
kidney transplant specifically
oedema, hypertension and tremor
lymph drainage to:
para-aortic
testes/ovaries
kidney
uterus
lymph drainage to:
superior mesenteric
lower duodenum, jejunum, ileum, colon to splenic flexure
association B27
seronegative arthropathy
psoriatic, reactive, enteropathic, ank spond
hypertension, gingival hyperplasia, hirsuitism
what drug side effects?
cyclosporine
tacrolimus
mechanism, use, toxicity
calcineurin inhibitor, binds FK-binding protein (other name for drug is FK506).
blocks NFAT, blocks IL-2
psoriasis and transplant
findings = cerebellar atrophy and lymphopenia, with decreased IgA, IgG and IgE
Ataxia-Telangictasia syndrome
function of IL-10
attenuates immune response
which antibodies activate compliment?
IgM and IgG
what are the two main opsonins against bacteria?
C3b and IgG
lymph drainage to:
popliteal nodes
dorsolateral foot
posterior calf
what isotype of anitbody is implicated in HSP?
what is the diagnostic test for this disease?
IgA
skin biopsy showing IgA immune complex deposition in blood vessels
macrophage surface markers?
CD14/TLR
CD40, CCR5 (can get HIV there too)
MHC II/B7
Fc and C3b receptors (regognise IgG and C3b as opsonins)
lymph drainage to:
superficial inguinal nodes (3)
below pectinate line
scrotum/vulva
skin below umbilicus (except pop fossae)
antimicrosomal antibody
disease?
hashimoto thyroiditis
what are the 4 opsonins?
IgG
C3b
MBL
CRP
examples of inactivated or killed vaccines?
influenza (shot)
Rabies
Polio (Salk)
hepatitis A
anti-smooth muscle antibody
disease?
autoimmune hepatitis type 1
filgrastim indication?
G-CSF - granulocyte stimulation only
what are the two signals for T cell activation?
MHC I or II with TCR
B7 with CD28
late separation of umbilical cord
what is the time in days? diagnosis?
> 21 days
leukocyte adhesion deficiency type 1, CD18 deficiency. cannot make CAMs on endothelial surface
what is the function of C5a?
neutrophil chemotaxis
telangictasia, cerebellar defects, IgA deficiency…
what’s the disease and what is the gene mutation?
Ataxia-Telangictasia syndrome
ATM mutation
explain chronic transplant rejection
CD4+ T cells activated by host APCs processing donor proteins from graft.
Activates both humoural and cellular response (type 2 and 4 HS)
histo - dominated by arteriolosclerosis
how is the structure of IgM different on B cells and in the circulation?
single antibody on B cell surface
pentamer in circulation
Trastuzumab
target and indication
HER2/neu
breast CA, gastric CA
‘HER2 - tras2zumab’
recurrent infection, partial albinism, peripheral neuropathy..
diagnosis? pathogenesis? defective gene?
susceptable to which organisms?
Chediak-Higashi syndrome
lysosome-phagosome fusion defect
defect in LYST gene
Staphylococcus and Streptococcus pyogenic infection
what is the principle of anti PD-1 therapy?
cancer.
PD-1 expressed on T cells, PD-L1 produced on target cells. PD-L1 neutralises cytotoxic T cells as a mechanism to promote self-tolerance.
PD-L1 overexpression on tumour cells is common.
PD-1 block restores cytotoxicity to T cells allowing cancer clearance
lymph drainage to:
mediastinal
trachea and oesophagus
when does Bruton’s present?
>6/12 old BOY
X linked and loss of maternal IgG
what are the inhibitors of complement?
DAF (CD55) and C1 esterase inhibitor
what stimulates Th2 development?
IL-2 and IL-4
anti-glutamic acid decarboxylase antibody
what disease?
T1Dm
what inhibits Th2 differentiation?
where is this produced?
IFN-gamma
Th1 cells
corticosteroids
mechanism, side effects, 2 special considerations
blocks NF-kB, blocks transcription of cytokines. induced T cell apoptosis
cushings, osteoporosis, hyperglyaemia/insulin resistance, amennhoroea, adrenal atrophy, peptic ulcers, psychosis, cataracts, avascular necrosis of femoral head
demargination of WBCs causes artificial leukocytosis. do not stop abruptly
how is an antigen loaded onto MHC II?
following invariant chain release in acidified endosome
what are the different anti-ABO antibodies and in which patient groups do they occur?
patient blood group A and B - anti-B or anti-A respectively, both IgM
patient blood group O - both anti-B and anti-A, IgG
explain the difference between Sabin and Salk vaccination
both for poliomyelitis
Sabin - live attenuated oral. better. stronger immunogenicity and direct mucosal stimulation prompts lasting duodenal IgA production
Salk - inactivated poliovirus. Cannot replicate so less immunogenic. Still gives serum IgG/IgM response. Better for immunocompromised.
functino of IL-3
like GM-CSF
risk of vertical transmission of HBV if mother is HBeAg positive and negative
how do we handle the children?
HBeAg + ve = 95%
HBeAg - ve = 20%
if foetus is infected with HBV vertically, there is 90% chance for conversion to chronic HBV. As such, passive (HBIG) and active (recombinant HBV vaccine) immunisation is given to all babies of HBV +ve mothers.
IFN gamma indication
chronic granulomatous disease
what isotype is anti-D given in obstetrics?
pooled IgG
what are the two B cell activating cytokines and what isotypes do they favour?
IL-4 = IgE and IgG
IL-5 = IgA and eosinophils
explain hyperacute transplant rejection
pre-existing anitbodies in host react to donor antigen (type 2 HS)
complement mediated
thrombosis in graft vessels, ishaemia and necrosis
association with DR3 (5)
T1DM, SLE, graves, hashimoto, addison
what ribs overlie the spleen?
9 - 11th
what is the gene defect in Wiskkott-Aldrich syndrome?
WASp
function of IL-4
induces Th2 cells
induces B cells
makes IgE and IgG
what is the cut off for HIV patients in CD4+ count that want MMR and varicella vaccine?
CD4+ T cells > 200
what is the difference between a 1ary and 2ary lymph node follicle?
1ary - dormant, only dense dark tissue
2ary - active, big pale central germinal centre
cyclosporine
mechanism, use, toxicity
calcineurin inhibitor by binding cyclophilin; NFAT blocked, IL-2 blocked
psoriasis, RA
nephrotoxic
four organ specific examples of chronic transplant rejection
lung - bronchiolitis obliterans
heart - accelerated artherosclerosis
kidney - chronic graft nephropathy
liver - vanishing bile duct syndrome
what cell surface marker do you use to identify NK cells?
CD56
what is the deficiency in hyper-IgM syndrome?
CD40L on Th cells
what inhibits Th1 cells and where does it come from?
IL-4 and IL-10
from Th2 cells
alemtuzumab
target and indication
CD52
CLL and MS
what antibody is secreted in breast milk?
IgA
eculizumab
mechanism and indication
anti-complement C5
PNH
daclizumab
mechanism and indication
CD25 (part of IL-2 receptor) blocker
relapsing MS
which bugs cleave IgA J chain?
Neisseria gonorrhoeae/meningitidis, Strep pneumo, haemophilus influenzae
examples of live attenuated vaccines?
up to 9
BCG, influenza (intranasal), measles, mumps, polio (Sabin), rotavirus, rubella, varicella, yellow fever
rituximab
target and indication
CD20
B-cell non-hodgkin lymphoma
CLL, RA, ITP
MMF
mechanism, indication, side effects
inhibits IMP dehydrogenase, prevents purine synthesis
Lupus nephritis
GI effects, pancytopenia, HTN, hyperglycaemia
C5-C9 deficiency results in what?
unable to form MAC but still able to opsonise
recurrent Neisseria bacteraemia
antiphospholipase A2 antibody
disease?
membranous nephropathy
palivizumab
mechanism and indication
blocks RSV proteins
prophylaxis for at risk infants
main role of LTB4?
neutrophil chemotaxis to the site of inflammation
how does staphylococcus superantigen work?
cross link the beta subunit of TCR to MHC II, meaning that any T cell will be activated becuase there is no specific antigen required. massive stimulation of cytokines.
TCR/MHC II binding also activates macrophages to secrete IL-1 and TNF-alpha
liver transplant patient presents with maculopapular rash, jaundice, diarrhoea, HSM…
diagnosis?
what other transplant is likely to suffer this disease?
GvHD
bone marrow
post transfusion
3 hours, respiratory distress and noncardiogenic pulmonary oedema
diagnosis, type of reaction, pathogenesis
TRALI (transfusion-related acute lung injury)
GvH
donor anti-leukocyte antibodies attacking neutrophils and endothelial cells in the host pulmonary vasculature
what does Th1 secrete?
INF-gamma, IL-2
function IL 1
fever and inflammation
endothelium adhesion molecules
WBC recruitment
association DR4 (3)
RA, T1DM, addison
indication for anti-TNFalpha?
IBD, RA, ank spond, psoriatic arthritis
anti-histone antibody
disease?
drug-induced lupus
sargramostim indication?
granulocyte and monocyte stimulation
GM-CSF
assoc HLA A3
haemochromatosis
cetuximab
target and indication
EGFR- epidermal growth factor receptor
CRC, head and neck CA
which cytokine induces actue phase reactact secretion from the liver?
IL-6
anti-desmoglein antibody
disease?
pemphigus vulgaris
a.k.a. anti-desmosome
function of IL-8
neutrophil chemotaxis
‘clean up on aisle 8’
what are the antiinflammatory cytokines released by T reg cells?
IL-10 and TGF-beta
anti-U2 ribonucleoprotein (RNP)
disease?
mixed CTD
mast cells are bound to IgE through high affinity receptor Fc epsilonRI.
what must happen at this receptor to stimulate mast cell degranulation?
a multivalent antigen must come in contact with the cell, localising many different IgE’s to the same place on in the cell. Fc epsilonRI aggregation leads to activation of downstream pathway and degranulation
dihydrorhodamine test abnormal (reduced green flourescence)…
diagnosis?
chronic granulomatous disease
what is activated by Th2?
eosinophils for parasites
promotes IgE from B cells
lymph drainage to:
axillary
upper limb
breast
skin above umbilicus
what are the blood and histological findings of serum sickness?
what HS reaction is this?
Type 3 HS - immune-complex mediated
blood - hypocomplementaemia (complement-fixing IgG/IgM is activated)
histo - small vessel fibrinoid necrosis and neutrophil infiltration
sirolimus (rapamycin)
mechanism, indications, side effects
inhibits mTOR by binding FKBP, prevents response to IL-2
specifically kidney transplant, drug-eluting stents
pancytopenia, insulin resistance, hyperlipidaemia
what is the B cell receptor that targets EBV to them?
CD21
what exposure requires emergency administration of preformed antibodies?
tetanus
botulinum
HBV
Varicella
Rabies virus
To Be Healed Very Rapidly
how does endotoxin/LPS work to activate the immune system?
bind to CD14/TLR to activate macrophages, Th not involved