CLASP Immunology Flashcards
(142 cards)
1
Q
Where do allergen-specific B cells encounter the allergen?
A
primary follicles of secondary lymphoid follicles
2
Q
What MHC molecule do B cells present peptides in?
A
MHC-II
3
Q
What is the function of IL-4 secreted by Th2 cells?
A
triggers class switching in activated B cells
4
Q
What are the functions of IL13 and IL5 produced by Th2 cells?
A
promote recruitment, activation and survival of eosinophils
5
Q
What substances do mast cells/eosinophils release?
A
histamine; tryptase and heparin
6
Q
What pro-inflammatory cytokines do mast cells/ eosinophils produce?
A
TNFa and IL4
7
Q
What position should you put a patient with anaphylaxis in?
A
lie patient flat and raise legs
8
Q
What is the dose of adrenaline given for anaphylaxis?
A
IM dose of 1:1000 (500mcg)
9
Q
When does type III hypersensitivity reactions occur?
A
excess of antigen causes immune complexes
10
Q
What is the difference in antigen between type 2 and type 3 hypersensitivity?
A
type 2: bound to cell surface; type 3: soluble antigen
11
Q
What is the function of C3a in type 3 reactions?
A
mediates induction of granule release from mast cells
12
Q
What is the function of C5a in type 3 reactions?
A
recruitment of neutrophils in to the tissue
13
Q
What are the 3 killing mechanisms of neutrophils?
A
phagocytosis; degranulation and NETs
14
Q
What chemical is involved in phagocytosis?
A
superoxide hydrogen peroxide
15
Q
What chemicals are invovled in degranulation?
A
lysozyme; NADPH oxidase; myeloperoxidase
16
Q
What are NETs
A
neutrophils extracellular traps which are structures of DNA that kill and tap microbes
17
Q
What type of T cells are invovled in the initial steps of type 4 reactions?
A
CD4 Th1 cells
18
Q
What cytokine do CD4 Th1 cells release in type 4 reactions?
A
IFN gamma
19
Q
What is the fcuntion of IFNgamma?
A
enhance macrophage activity and promote further inflammation and recruitement of other cells eg CD8
20
Q
How do cytotoxic T cells destroy cells?
A
peptide/MHC-I manner
21
Q
What type of drugs can cause false positives in skin prick testing?
A
monoamine oxidase inhibitors and TCAs
22
Q
What are the typical signs of small vessel vasculitis?
A
purpura; vesiculobullous lesions; urticaria; glomerulonephritis; alveolar haemorrhage; cutaneous extravascular necrotising granulomas; splinter haemorrhages; scleritis/episcleritis/uveitis
23
Q
What are the typical signs of medium vessel vasculitis?
A
cutanoeous nodules; ulcers; livedo reticularis; digital gangrene; mononeuritis mutliplex; microaneuryms
24
Q
What are the typical signs of large vessel vasculitis?
A
limb claudication; asymmetric BPS; absence of pulses; bruit; aortic dilatation
25
Give examples of large vessel vascultides?
takayasu arteritis; GCA
26
Give example of medium vessel vasculitis?
PAN; kawasaki
27
Give examples of vasculitis type 3 hypersensitiity?
SLE; PAN
28
Give examples of vasculitis which are type 4 hypersensitibity?
GCA; takayasu
29
Where does inflammation in the vessels in takayasu start?
in the adventitia and moves toward intima
30
What are the immunological features of steroid use?
lymphocytopenia; neutrophilia; secondary immunodeficiency
31
What are the endocrine features of steroid use?
DM; HT; increased appetitie and weight gain; adrenal cortex suppression
32
What are the skin/soft tissue features of steroid use?
cushingoid appearance; abdominal striae; acne; hirsutism; oedema; increased risk of skin cancer
33
What are the neuro features of steroid use?
neuropathy; pseudomotor cerebri/ IIH
34
What are the ophthalmic features of steroid use?
cataracts; narrow-angle glaucoma
35
What are the MSK features of steroid use?
oseopenia; AVN; myopathy
36
What are teh CVS features of steroid use?
HT
37
What type of hypersensitiity is cryoglobulinaemiac vasculitis?
type 3
38
What mediates the damage in cryoglobulinaemic vascultiis?
complemetn
39
What is the function of RF in RA?
predicts extra-articular features
40
What are the psychiatryic effects of acute steroid use?
insomnia; agitation; depression/anxiety; psychosis
41
What are the GI effects of actue steroid use?
GI haemorrhage
42
how do steroids cause GI haemorrhage?
inhibit phospholipase A2 which converts cell membrane phsopholipis into arachidonic acid- reduced LTs and PGs
43
What activates complement in the classical pathway?
Fc portion of antiobdy
44
Which type of antibody is best at activating complement?
IgM- pentamer
45
Which antibodies can activate complemetn?
IgM and IgG
46
What complemetn binds to the Fc region of hte heavy hcain?
C1
47
What is C4b2a known as?
C3 convertase
48
What part of C1 binds to antibody?
C1q
49
What must happen for C1q to become firmly fixed?
cross link at least 2 antibody molecules before firmly fixed
50
What does the binding of C1q cause?
activation og C1r which activates C1s
51
What is the function of C1qrs?
cleaves C4 into C4a and C4b; and C2 into C2a and C2b
52
What is C4bC2aC3b known as
C5 convertase
53
What happens in the alternate pathway?
bacterial, fungal and viral cells surfaces bind C3 and factor B
54
What is the C3 and factor B cleaved by?
factor D
55
What does cleavage by factor D procue?
C3bBb
56
What is the function of C3bBb?
C3 convertase
57
What initiates the lectin pathway?
mannose-binding lectin to bacterial surface
58
What does binding of MBL to a pathogen result in?
association og 2 serin proteases MASP-1 and MASP-2
59
What does the activation of the MASPs restul in?
cleave of C4 and C2
60
What forms MAC?
C5b which activates C6-C9
61
What are isohaemoagglutins?
natural IgM antibodies to group antigens A and/or B
62
When would expect specific antibodies to protein antigens?
within 2 weeks
63
When would youexpect an antibody response to polysaccharide antigen?
4-6 weeks
64
What is the difference in onset between congenital antibody deficiencies and congential cellular immunodeficinesi?
antibody- onset 7-9 months usually (3-18 months); first months of life for cellular
65
What is the function of RAG-1 and RAG-2 ?
first cleavage step in somatic recombination of immunoglobulin genes
66
What condiiton have Rag mutations?
SCID
67
What is the most severe form of SCID?
reticular dysgenesis
68
What name is Kostamnn syndrome also known as?
severe congential neutropenia
69
What is the inheritance of kostmann syndrome?
AR
70
What side effects is granulocyte colony stimulating factor implicated in?
AML; myelodysplastic syndrome
71
What is the most common genetic cause of CGD?
x-linked deficinecy of NADPH oxidase
72
What is the test fo CGD?
nitroblue tetrozolium test- a dye sensitive to hydrogen peroxide
73
What is the second commonest cause of pancreatic exocrine insufficnecy?
schwachman-diamond syndrome
74
What is the inheritance of cyclic neutropenia?
AD
75
What is the most common form of neutropenia seen in young children?
primary autoimmune neutropenia
76
What is the mutation in XLA?
brutons tyrosine kinase?
77
What does the mutations in BTK cause?
block in B cell maturation
78
What is the cause of hyper-IgM?
B cell inability for class switching
79
What type of infections are seen with antibody deficiency?
encapsulated bacteria
80
How can leukocyte adhesion deficiency present with?
severe gingivostomatitis and dental erosion
81
What producd by macrophages stimualtes the liverto produce acute phase proteins?
TNFa; IL1 and IL6
82
What causes leukocyte adhesion deficiency?
mutation in leucocyte integrins
83
What are the 3 groups of moelcules which interact to cause adhesion and transmigration?
leukocyte integrins; endothelial intercellular adhesion molecules and glycosaminoglycans or selectins
84
What molceules are involved in firm adhesion?
integrins and ICAMs
85
What is dariers sign?
urticaria after stroking or rubbing affected skin
86
What conditions cause dariers sign?
systemic mastocytosis; urticaria pigmentosa
87
What natibody is reduced with CVID?
IgG
88
What drugs have been implicated in the development of CVID?
anti-rhuematic and anticonvulsants (phenytoin)
89
What are B cels in CVID not able to do?
form memory B cells and mature plasma cells
90
What causes digeorge syndrome?
failure of pharyngeal pouches 3 and 4 to differentiate into thymus and parathyroid glands
91
what is IgG2?
sublass of IgG that is produced in reposnse to polysacchraide antigen by B cells in the spleen without T cells
92
What other antibiotic classes wre pencillin allergy patients often also allergic to?
cephalosporin and carbapenems
93
What chemokines are invovled in chemotaxis?
IL8; TNFy and C5a
94
Give examples of encapsulated bacteria?
strep. pneumo; h. influenzae
95
What other type of infections are patients with antibody deficiency more likely to get?
infectious diarrhoea
96
How is the definitive diagnosis of CGD made?
male or female with abnormal NBT or respiratory burst in activated neutrophils who has mutations or family history
97
Where are the mutations in CGD found?
NADPH oxdase copmlex
98
What are the 2 types of genetic mutation found with CGD?
X-linked and AR
99
What is the difference in X-linked and AR forms of CGD?
X-CGD is majority of patients and present earlier and have more severe disease
100
What are the symptoms of X-CGD?
failure to thrive; severe bacterial and fungal infections
101
What is the differential diagnosis of CGD?
LAD; sarcoid; hyper-IgE syndrome
102
How are neutrophils activated?
binding of bacterialor fungal frgamnets to Fc, complement or PRRs, particle is internalised and cell activated
103
Where are the ROS and toxins found in the neutrophil?
phagosome
104
What is the function of hte H ion produced by the NADPH oxidase complex?
acidification in phagosome speeds up breakdown
105
What is the respiratory burst?
increase in O2 consumption during production of microbicidal oxygen metabolites
106
The respiratory burst occurs in which cells/
neutrophils and macrophages
107
What is SCID?
adaptive immune responses do not occur due to lack of T cells and impaired B function
108
How is the diagnosis of SCID made?
male/female patient less than 2 years with <20% CD3 T cells and absolute lymphocyte count <300
109
What are the common presenting illnesses in SCID?
PCP; significant bacterial infections and disseminated BCG infection
110
What are the symptoms of SCID?
failure to thrive, persisten diarrhoea; resp symptoms and/or thrush in first 2-7 months
111
What is the prognosis of SCID?
fatal in first 2 years without treatment
112
What infections are seen with complement deficiency?
>1 episode of invasive mengococcal infection or other neisserial bacterial
113
What are the main tests of complement system activity?
CH50 and AP50
114
What does the CH50 test asses?
classical complement pathway
115
What would result in an abnormal CH50 test?
deficiencies of C1-C9 or consumption of complement due to immune complexes
116
What is the function of the AP50 test?
alternative pathway
117
What is the MAC formed by?
C5b and C6-9
118
What complement components are invovled in inflammation?
C5a and C3a
119
What complement is an opsonin?
C3b
120
Which complement is invovled in immune complex solubilisation?
C3b
121
What are teh 2 main categories of complement problems?
disorders invovling inhibitors of complement system; activators of complement system
122
What conditions are invovled with problem of inhibitors of complement?
hereditary angioedema; haemolytic -uraemic syndrome
123
What is the diagnosis of LAD made with?
decreased intensity of expression of CD18 on neutrophils
124
What gene encodes CD18?
beta2 integrin gene
125
What are the features of LAD?
recurrent/persistent bacterial.fungal infections; leukocytosis; delayed separation of the umbilical cord; and/or defetive wound healing; periodonitis
126
Which types of infection are particularly problematic with LAD?
staphylococcus; gram negative enteric bacteria nad fungal infections
127
What is the diagnosis of XLA made with?
male patient with low levels of CD19+ B cells and mutation of BTK gene
128
What are the common organisms in XLA?
strep pneumo and h.influenza
129
When is the diagnosis of CVID usually made?
third of fourth decade
130
What are the usual presenting features of CVID?
reucrrent infections invovling the ears; nasal sinuses; bronchi and lungs
131
what does both low CH50 and AP50 suggest?
problem in terminal MAC pathway
132
What is the function of immunoglobulin replacement therapy?
reduce freq of infections and risk of lung damage
133
What is hypogammaglobulinaemia defined as?
value is less than 2 SD below age-adjusted normal
134
what is the diagnosis of CVID?
low IgG with low IgA and/or IgM as well as defective antibody repsone to vaccine; exlusion of other PIDs
135
What are the treatment options for LAD?
prophylactic antibiotics; haematopoeitic stem cell transplant
136
What are the treatment optiosn for CGD?
prophylactic antibiotics/anti-fungals; IFNgamma; steroids
137
What ILs and TNF can contribute to cachexia and fever?
IL1 and TNFa (cockexia- alpha is balls and 1 is shaft)
138
What IL is involved in T cell activation?
Il2- 2 cell activation
139
What IL is the bone marrow stimulant?
IL3- 3-some if you wanna bone
140
what is the eosinophil activator?
IL5- 5 fingers on the hand, and hand looks like eosinophil-2 lobes
141
What is the neutrophil chemotactic agne?
IL8- on side looks like infinity (most infinite WBC)
142
What is the granuloma activator?
IFN-gamma (activates macrophages to make granulomas) G for granuloma
