Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Haematology and Immunology > Immunodeficiency > Flashcards

Immunodeficiency Flashcards

(58 cards)

Start Studying
1
Q

What are the features of innate immunity?

A

Structures shared by microbes, recognised as patterns - PAMPs
Germline encoded recognition receptors
Immediate speed of response
No memory
Complement components
Cellular components - dendritic cells, neutrophils, macrophages + NK, NKT , B1 , epithelial and mast cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the features of adaptive immunity?

A

Wide range of very particular molecules or fragments of molecules
Somatic mutation results in wide range of specificities and affinities
Time for cell movement and interaction between cell types
Efficient memory
Antibodies
Lymphocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the barriers to infection in innate immunity?

A

Physical/ mechanical and biological

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the antigen presenting cells of the immune system?

A

Macrophages and dendritic cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the functions of the B cell?

A

Differentiates into plasma cells producing antibodies
Opsonization
Complement activation
Toxin neutralisation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the functions of the T cell?

A

Helper T cells provide B cells with signals necessary for antibody production
Cytotoxic T cells destroy virally infected cells and tumour cells
T regulatory cells suppress auto-reactive T cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the functions of phagocytes?

A

Engulfs and destroys microbes
Antigen presentation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the functions of complements?

A

Opsonization
Terminal components create the membrane attack complex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the function of NK cells?

A

Destroys virally infected cells and tumour cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How is immunodeficiency classified?

A

Primary (intrinsic defect) - innate or adaptive (congenital or late onset)
Secondary (underlying disease) - production or loss (always acquired)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the consequences of primary immunodeficiency?

A

Infections, autoimmunity, inflammation, atopy and malignancy
Often a delay in diagnosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are some consequences of primary immunodeficiency on T cells and phagocytes?

A

T cell - pneumocystis jerovecii pneumonia
Phagocyte - delayed separation of the umbilical cord (LAD) and disseminated NTM

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

When is primary immunodeficiency suspected?

A

FH, recurrent/ chronic infection, infections with unusual organisms, early-onset eczematous skin rashes, early-onset autoimmunity and failure to thrive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is defined as recurrent infections?

A

4 or more ear infections a year
2 or more serious sinus infections, pneumonias or deep seated infections/ sepsis per year

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the investigations in primary immunodeficiency in B cells?

A

FBC with differential
Immunoglobulin levels and subset
Flow cytometry for B cell subset
Functional antibody responses against vaccines

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are the investigations in primary immunodeficiency for T cell?

A

FBC with differential
Flow cytometry for T cell subset
T-cell proliferation to mitogens and antigens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are the investigations for phagocytes in primary immunodeficiency?

A

FBC with differential
Neutrophil oxidative burst assay
Th1 cytokines and autoantibodies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are the investigations in primary immunodeficiency for complements?

A

Individual complement components
CH50 and AP50

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are the investigations in primary immunodeficiency for NK cells?

A

Flow cytometry for NK cell numbers
NK cell functional assays

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the management for primary immunodeficiency?

A

Antimicrobials - Prophylactic and aggressive treatment for clinical infection
Replacement - immunoglobulin replacement therapy
HSCT - haematopoietic stem cell transplant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Describe the epidemiology of primary antibody deficiency

A

Commonest form of primary immune deficiencies
Occurs in children and adults - may be congenital or late onset
More common to present in 4-15 yrs and 16-60 years
Most people who fail to produce protective antibodies present after 10 years of age

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What are the clues from presentation in primary antibody deficiency?

A

Recurrent sinus/ chest infections, second system involvement, infections due to common bacteria, fungal + viral infections are uncommon and non-infectious features common (ITP)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is the management for primary antibody deficiency?

A

Replace IgG - IV or SC
Antibiotics
Immunisation
Look after lungs - physio and exercise
Treat cause
Monitor and support

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Describe immunoglobulin replacement

Study These Flashcards
A

IV 2 to 3 weekly or SC weekly/ twice weekly
Aim to prevent infections - need 400-600mg per month
Derived from plasma pool

25
Describe transient hypogammaglobulinemia
Physiological IgG trough - infant has IgG equal to mother at birth then catabolism of maternal IgG outstrips IgG synthesised by the newborn As maternal acquired antibodies fall, infant becomes susceptible to recurrent pyogenic infections
26
Describe Burton's disease
XLA - X-linked so affects young boys Failure to differentiate further from pre-B-lymphocyte so get recurrent pyogenic infections (no plasma cells or antibodies) Mutation on BTK gene
27
What is the management of Burton's disease?
Immunoglobulin replacement Antibodies
28
Describe Hyper IgM syndromes - CD40 ligand deficiency and AID deficiency
Severe antibody deficiency but normal B cells and normal/ raised serum IgM levels Failure of expression or functional activity of ligand results in failure of switching and poor organisation of germinal centres
29
Is Hyper IgM syndromes autosomal or X-linked?
X-linked due to CD40 ligand deficiency on T cells Pure B cell form is deficiency of enzyme AID
30
Describe common variable immunodeficiency
Heterogenous group of disorders - variable nature of conditions Most are not diagnosed until adulthood Low serum levels of IgG and IgA with normal/ reduced IgM and B cells Most live normal lives on immunoglobulin replacement
31
What is the presentation seen in common variable immunodeficiency?
Hypogammaglobulinemia causes recurrent infections - all patients Polyclonal lymphoproliferation - lymphadenopathy Autoimmune cytopenia - ITP and AIHA Unexplained enteropathy No disease related complications
32
Describe selective IgA deficiency
Commonly picked up on incidental findings Undetectable or very low serum IgA levels with normal IgG + IgM and production of normal antibodies to pathogens Most are healthy
33
What is the clinical relevance of selective IgA deficiency?
Coeliac disease diagnosis - anti-TTG IgA Associated to development of coeliac disease Anaphylaxis risk with blood products
34
What are the adaptive causes of primary immunodeficiency?
Antibody deficiency Combined deficiency - depressed T cell function is usually accompanied by variable B-cell abnormalities
35
What are 2 examples of primary immunodeficiency?
Di-George syndrome Wiskott-Aldrich syndrome
36
Describe Di-George syndrome
Thymus is abnormal - CD3 cells are low If CD3 cells are absent - stem cell transplant is urgent 22q11del CATCH22 Variable T cell quantities and normal B cell levels
37
What does CATCH 22 stand for in DI-George syndrome?
Cardiac defects Abnormal faces Thymic aplasia Cleft palate Hypoparathyroidism
38
Describe Wiskott-Aldrich syndrome
Mutation in WAS gene - leukocytes and platelet unable to recognise cytoskeleton T-cell receptor function is affected X-linked Combined B and T cell disorder with impaired antigen presentation
39
What is the triad of Wiskott-Aldrich syndrome?
Immunodeficiency - recurrent pyogenic infections Thrombocytopenia - bleeding Eczema
40
Describe SCID - severe combined immunodeficiency
Immunological emergency Diminished T cell function and abnormal B cell function Absolute lymphocyte count is less than 2x10^9
41
What is the presentation of SCID?
Infections within first few months, failure to thrive and immune dysregulation Chronic diarrhoea and chronic respiratory virus is common Lymphopenia is present so rule out HIV
42
What is the normal lymphocyte count in children?
Fivefold higher than adults Higher proportion of B cells Fewer CD8 cells at birth Absolute counts are essential
43
What are the types of SCID?
Reticular dysgenesis - autosomal recessive and no stem cells Adenosine deaminase - autosomal recessive + toxic metabolites build up and kill precursor cells Gamma chain - X-linked RAG1/2 - autosomal recessive and lack of VDJ recombination Multiple defects
44
Describe SCID newborn screening test
Heel prick test - DNA extraction - PCR amplification If normal TREC:B actin then no further action If low then urgent assessment by immunologist
45
What is the management of SCID?
Haematopoietic stem cell transplantation (HTC) Gene therapy Enzyme replacement
46
What are the professional phagocytic cells?
Monocyte/ macrophage, neutrophils, dendritic cells and mast cells Involved in extravasation, recognition and phagocytosis
47
How is neutropenia classified?
Decreased production with marrow hypoplasia - can be primary or secondary Increased destruction with marrow hyperplasia
48
What is G-CSF involved in?
Proliferation, differentiation, maturation, suppression of apoptosis and functional activation
49
What is the extravasation?
Chemoattraction of leukocyte - tethering _ rolling - migration causing inflammation and chemokines
50
Describe leucocyte adhesion deficiency (LAD)
Failure to adhere to endothelial cells and can't transverse into tissues Skin infections, gingivitis, deep abscesses, peritonitis, osteomyelitis and delayed separation of umbilical cord
51
What are the steps of recognition?
Ligand coated particle Phagocyte surface receptors Receptor cluster Activation and entry then signal
52
Describe chronic granulomatous disease
Reduced oxidative metabolism - failure to kill pathogens DHR screening test X linked, recurrent infection, staph skin infections, lymphadenopathy and granuloma formation
53
What are the 3 pathways of complements?
Classic - antigen-antibody reaction Lectin - mannose binding lectin Alternative - microbes or injured tissue
54
What is the affect of immune-complex diseases?
Recurrent bacterial infection and Neisseria infections
55
What is an example of immune complex disease?
Hereditary angioedema - deficiency of C1 inhibitor and low C4 levels
56
What are pattern recognition receptors?
Are strategically located within cells Each receptor recognises molecular patterns exclusive to pathogens or molecular patterns that are in an inappropriate compartment
57
Describe TLR3 deficiency - HSV encephalitis
dsRNA made as a biproduct of HSV replication TLR3 sense dsRNA to initiate immunological and antiviral response
58
What is the aetiology of secondary immunodeficiency?
Production - malnutrition, drugs (chemo and immunosuppressants), malignancy (CLL and myeloma) and infections (HIV) Loss - nephrotic syndrome, burns and protein-losing enteropathy

Haematology and Immunology (17 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions