Immunology Flashcards
Cd4 and 8 cells are otherwise known as?
Cd4 T helper
Cd8 cytotoxic T
What CD number is given to B cells and NK cells
B-19 and 20
NK-56
How many resp infections are seen in a normal child in a year
What might increase it
8-12
Daycare/school age self or sibling
What is the most common subgroup of immunodeficiency
What type of organisms usually infect
When do they usually present? Why?
B cell defects
Encapsulated organisms- pneumococcus HIB
Giardia
Enterovirus
After 6 months- maternal IgG has run out
How are B cell deficiencies treated
What is the half life
IVIG
30 days
What happens lymphoid tissue in B cell defects
Absent unless CVID
What are associations with B cell immunodeficiency
Reduced growth
Increased allergy and autoimmune disease
What is selective igA deficiency
How does it present
How frequently is it seen
Normal b and t cells but reduced igA
80% are asymptomatic, others like B cell defects
1:500 people
Does selective igA deficiency need IVIG
No!
Why should selected iGA deficiency have washed blood products
Which autoimmune disease is highly likely
High risk of transfusion reactions
Coeliac disease
What is the significance of IgG deficiency
Unknown!
What is x linked agammaglobulinaemia otherwise known as
What happens physiologically
What is seen on bloods
Brutons disease
Lack bruntons tyrosine kinase
B cells can’t mature from bone marrow
Low iGA, M and G and low circulating mature B cells with poor vaccine responses
What is x linked agammaglobulinaemia linked to
Inflammatory bowel disease
Hyper iGM syndrome
What is the pathology
What is the usual inheritance
Can’t switch IG subclasses- lack CD40 ligand
Lots of iGMs but lack the rest
X linked recessive
Hyper igM syndrome
What other infections do they get
What other abnormality do you see on blood tests
How therefore may they present
PCP
Neutropenia
Suspicion of HIV
Which B cell defect can have a fatal response to mono
Duncan’s- x linked lymphoproloferatove disease
What is hyper igE syndrome otherwise know as
What are 2 common features other than immune deficiency
Jobs syndrome
Severe eczema
Double rows of teeth
When does transient hypogammaglobulinaemia of infancy usually resolve by
Do they have normal B cell numbers and vaccine responses
2 yrs
Yes!
What immune cells are affected in CVID
When do they normally present?
What are they at risk of
What is seen on bloods
B can’t transform into T
Adolescence/ adults
Lymphomas and autoimmune diseases
Normal b and T cell numbers
Low IgG, M and A
May be pancytopenic
CVID
What happens to their lymphoid tissues
Is it more common in boys?
Increases- tonsils and spleen
No!
CVID
What defines severity
Do they get granulomas
Severity of the T cell defect
Yes- non caseating
What 5 tests are useful in looking at T cell defects
Lymphocyte count Cxr? Thymus Lymphocyte subsets (B/T/NK) Lymphocyte phenotypes (CD4,8,19,20) Lymphocyte function to stimulation
T cell defects
What types of organisms do they get
Opportunistic
PCP
CMV
Candida
What percentage of velocardiofacial syndrome have complete thymic hypoplasia
25%
SCID
What test is used in newborn screening
What is seen most profoundly on bloods
T cell receptor excision circles
Lymphopenia
SCID
Will they have normal lymphoid tissue
What is seen on cxr
No- reduces or absent
Absent thymus
SCID
Which gene defect has available treatment
What is the most common genetic mode of inheritance and gene involved
ADA
X linked-IL2
WAS
What is the gene involved and inheritance
What is the usual triad
What malignancy is more likely
WASP x linked recessive
Thrombocytopenia eczema and immunodeficiency
Lymphomas
WAS
What is the pattern of immuglobulin changes
High igE and A
Low igM
(High ethanol alcohol, low mental state )
SCID
how do they present if not found on screening
Severe diarrhoea and FTT
Opportunistic infections
GVHD
What stain is positive on lung biopsy in PCP
Methenamine silver nitrate
What rash is seen on omen syndrome
Which gene is involved
Erythroderma with skin peeling
RAG gene
Which ataxia syndrome is associated with b and T cell issues
Ataxia teliengiectasia
What type of infections are seen in phagocytic disease
Which organisms are seen
Gingivitis and ulcers
Abscesses
Deep and soft tissue infections.
Staph pneumococcus and aspergillus
What are the 2 best tests for phagocytic diseases
Neutrophil count
Dihydroamine flow assay (neut function test)
What is the usual pattern of inheritance for chronic granulomatous disease
What does it mimic
X linked recessive
Crohn’s disease
Chronic granulomatous disease
What is seen in wcc and igg
Raised WCC and IgG
Chronic granulomatous disease
What enzyme is lacking
Lack in NADPH Oxidase
What is wrong with the lymphocytes in LAD 1 and 2
What is seen with the WCC
What is likely to be seen after birth
1- can’t adhere
2- cant roll
Always elevated
Delayed cord separation
Which disorder of phagocytes presents with metaphyseal dysplasia
Cartilage hair dysplasia
Chediak higashi
Phenotypically what is seen
With us the issue with the white cells
What other 2 things do they get
Red hair or albinism
Wcc granules are too big, can’t degranulate
Leukaemias and peripheral neuropathy
Which gene is common in cyclic neutropenia
How frequently should bloods be done
ELANE
Twice weekly neuts for 6 weeks
What is the pathological cause of hereditary angiodema
C1 esterase deficiency
What complement is involved in sle
What infections are seen
C3
Encapsulated
In late complement pathway defects what infections are commonly seen
What other rare defects can also give this
Recurrent neissera
Properidin def, factor D def
Which test assesses classical and terminal complement pathways
Alternative
CH50
Ah50
What are interleukins?
Types of cytokines- pro inflammatory
What do the following activate
1,2,3,4,5
1- macrophages- fever 2-T - T cells 3-b- B cell activation 4- igE- class switching 5- eosinophils iGA 6- CRP
Hot T BonE stEAk
Antibodies
What are they made up of
What is the antigen biding portion called
What are the 2 regions?
What are the half lives for the following
IgA,M,g,E
Which crosses breast milk
Which crosses the placenta
2 heavy and 2 light chains
FAB region
Constant and variable portions
IGA-7 days
IgM- 5 days
IgG 21 days
IgE 3 days
IgA
IgG
Which 2 immune cells do you need for class switching
CD40 and helper T cells
What is the half life of IVIG
30 days
Which MAB is a terminal pathway inhibitor
Ecilizumab
Which antibody activates the classical complement pathway? alternative?
Classical- ab/ag complexes
Alternative- igA
What is the best test for hereditary angiodema?
During an attack what 3 things go low
How is it treated
C4 level and c1 inhibitor activity
C2,4 and CH50
C1 inhibitor concentrate
What pathway is involved In Mendelian susceptibility to mycobacterium disease
Il12
