Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Y5 Immunology > Primary immune deficiencies > Flashcards

Primary immune deficiencies Flashcards

1
Q

What is reticular dysgenesis? General + mutation/inheritance

A

Defect of haematopoetic stem cells: failure of stem cells to differentiate along myeloid or lymphoid lineage- failure of production of neutrophils, lymphocytes, monocyte/macrophages, platelets

Autosomal recessive - most severe SCID

Mutation in mitochondrial energy metabolism enzyme adenylate kinase 2 (AK2)

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

What is Kostmann syndrome?

A

Failure of neutrophil maturation

Autosomal recessive severe congenital neutropenia

Mutation in HCLS1-associated protein X-1 (HAX1)

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

What is cyclic neutropenia?

A

Failure of neutrophil maturation
Autosomal dominant episodic neutropenia every 4-6 weeks
Mutation in neutrophil elastase (ELA-2)

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

Usual expression by neutrophils to bind to endothelial cells/regulate neutrophil adhesion and what is wrong in leukocyte adhesion deficiency

A

CD11a/b- CD18 expressed on neutrophils to bind to ligands on endothelial cells

Deficiency of CD18 - neutrophils lack adhesion molecules and fail to exit bloodstream

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

Very high neutrophil counts in blood, absence of pus formation, delayed umbilical cord separation. What is the diagnosis?

A

Leukocyte adhesion deficiency

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

What is the problem in chronic granulomatous disease? How does the disease present?

A

Deficient in NADPH oxidase- oxygen not converted to superoxide that is needed for hydrogen peroxide- impaired killing

Excessive inflam: persistent neutrophil/macrophage accumulation; failure to degrade antigens

Presents:
Granuloma formation
Lymphadenopathy and hepatosplenomegaly
Susceptibility to bacteria (esp catalase positive - PLACESS)

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

Investigations for chronic granulomatous disease and treatment

A

Negative Nitro-Blue Tetrazolium (NBT) test- NBT changes yellow->blue if hydrogen peroxide

Dihydrorhodamine (DHR) flow cytometry- DHR oxidised to rhodamine (fluorescent) if hydrogen peroxide

Treatment: interferon gamma

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

How do mycobacteria/BCG/Salmonella stimulate oxidative killing. What is the effect of cytokine/receptor deficiencies on this?

A

Mycobacteria activates IL-12- IFNy network:

  • Infected macrophages produce IL-12
  • IL-12 causes T cells to secrete IFNy
  • IFNy feedsback to macrophages and neutrophils and stimulated TNF production -> activated NADPH oxidase

IL-12, IL-12 receptor, IFNy and IFNy receptor deficiencies: inability to form granulomas - susceptibility to mycobacteria infection

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

General pathway affected in Factor B/ Factor D/ Factor P (properdin) deficiency

A

They normally stabilise C3 convertase that triggers memebrane attack complex (MAC)

Deficiency -> inability to mobilise complement in bacterial infection (recurrent encapsulated infection)

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

What is the role of the C1/C2/C4 classical complement pathway. Problems resulting from deficiency

A

Roles: phagocyte clearance of apoptotic cells/nuclear debris, clearance of immune complexes.

Deficiency-> infection susceptibility, increased self-antigens (SLE/autoimmunity), deposition of immune complexes in tissue/vessels (SLE)

SLE, sever skin disease, increased no. of infections

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

What primary immune deficiency is associated with SLE

A

c1/2/4 classical compliment pathway deficiency

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

Mannose binding lectin (MBL) deficiency. In what patients might you see increased infection

A

Premature infants
Chemotherapy
HIV infection
Antibody deficiency

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

What infections are patients with C3 complement deficiency susceptible to

A

Meningococcal septicaemia

Encapsulated bacteria:
Neisseria meningitidies - esp in properidin and C5-9 deficiency
Haemophilus influenzae
Streptococcus pneumoniae

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

How to nephritic factors affect complement? What are they associated with

A

Nephritic factors are autoantibodies complement components

Nephritic factors stabilise C3 convertase -> C3 over-activation and consumption

Associated with glomerulonephritis (membranoproliferative) and sometimes partial lipodystrophy

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

C3 normal, C4 normal, CH50 low, AP50 normal

A

C1q deficiency

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

C3 normal, C4 normal, CH50 normal, AP50 low

A

Properdin /Factor B/D/P deficiency

17
Q

C3 normal, C4 normal, CH50 low, AP50 low

A

C9 deficiency

18
Q

C3 normal/low, C4 low, CH50 normal/low, AP50 normal

A

SLE

19
Q

Neutrophil count absent , leukocyte adhesion markers normal, NBT oxidative killing absent, no pus

A

Kostmann syndrome - congenital neutropenia

20
Q

Neutrophil count increased, leukocyte adhesion markers absent, NBT oxidative killing normal, no pus

A

Leukocyte adhesion deficiency

21
Q

Neutrophil count normal, leukocyte adhesion markers normal, NBT oxidative killing abnormal, pus present

A

Chronic granulomatous disease

22
Q

When and how does SCID present

A

Around 3 months - until then IgG from placenta/colostrum milk

All types infection
Failure to thrive
Persistent diarrhoea
Unusual skin disease
Maternal lymphocytes colonise empty infant bone -> graft vs host
FHx early infant death
23
Q

Mutation causing and problems in X-linked SCID

A

Mutation of common gamma chain of IL2 receptor on chromosome Xq13.1

  • Shared by cytokine receptor for IL-2,4,7,9,15,21
  • Cannot respond to cytokines-> no T cell/NK cell development and immature B cells

Low/absent T and NK cells
Normal or increased B cells, but low Igs

24
Q

ADA deficiency

A

Adenosine Deaminase - enzyme for lymphocyte metabolism

Low/absent T, NK and B cells

25
Q

What is the mutation/gene/acquision in DiGeorge Syndrome?

A

Deletion at 22q11.2
TBX1 may be responsible for some features
Usually sporadic>inherited

26
Q

What is the problem in DiGeorge Syndrome? What features will you see?

A

Developmental defect of the pharyngeal pouch

Cardiac abnormalities -tetralogy of fallot
Abnormal facies - high forehead, low set ears
Thymic aplasia (T cell lymphopenia)
Cleft palate, small mouth and jaw
Hypocalcaemia/hypoparathyroidism
22-chromosome

Reduced T cells
Normal B cells
Impaired immune function, improved with age

27
Q

What is the problem in Bare Lymphocyte Syndrome Type 2

A

Defect in regulatory protein for class II gene expression-> absent MHC Class II

Profound deficiency in CD4+
Normal CD8+
Normal B cells
No IgG or IgA (no isotype switching)

28
Q

CD4+ low, CD8+ low, B cell normal/low, IgM normal/low, IgG low

A

SCID

29
Q

CD4+ low, CD8+ low, B cell normal, IgM normal, IgG low

A

DiGeorge syndrome/ 22q11.2 deletion syndrome

30
Q

CD4+ low, CD8+ normal, B cell normal, IgM normal, IgG low

A

Bare lymphocyte syndrome T2

31
Q

Where is the problem in Bruton’s X-linked hypogammaglobulinaemia? Clinical presentation?

A

Abnormal B cell tyrosine kinase (BTK) gene- B cells cannot develop

Absence mature B cells, no circulating Ig after 3 months

Clinical pres:

  • BOYS
  • Recurrent infection during childhood - bacterial (otitis med, pneumo, sept arth, osteomyeli, gastroenter), viral, fungal, parasitic, enterovirus, penumocystitis
  • Absent/scanty lymph nodes and tonsils (absent primary follicles/germinal centres)
  • Failure to thrive
32
Q

Inheritance of Hyper-IgM syndrome? What is the problem? Clinical presentation and bloods

A

X-linked recessive
Mutation in CD40 ligand gene - CD40 usually expressed by T cells/APC to B cells
IgM cells cannot differentiate - no class switching

Failure to thrive in boys in early years
Recurrent bacterial infections
Pneumocystis jiroveci, autoimmune, malignancy

Normal circulating B cells
Normal T cells (but do not express CD40 ligand)
Elevated IgM
No IgA, IgE, IgG (no class switching)
Nor germinal centre in lymph node/spleen
33
Q

General issue in common variable immune deficiency? Clinical features?

A

Failure of differentiation/function of B lymphocytes

Reduction in IgG, maybe low IgA/IgM
Poor response to immunisation

Children or adult
Recurrent bacterial infection w/ end organ damage - pneumonia, sinusitis, gastroent
Pulmonary disease - bronchiectasis, obstructive disease, interstitial/granulomatous
GI - IBD-like, sprue like, bacteria overgrowth
Autoimmune - AIHA, Rh arth, pern anaem, thyroiditis, vitiligo
Malignancy - non-hodgkin

34
Q

Either asymptomatic or recurrent RTI. Gi infections. CD4+ normal, CD8+ normal, B cell normal, IgM normal, IgG normal, IgA low

A

Selective IgA deficiency

35
Q

CD4+ normal, CD8+ normal, B cell low, IgM low, IgG low, IgA low

A

Brutons X-linked hypogammaglobulinaemia

36
Q

CD4+ normal, CD8+ normal, B cell normal, IgM high, IgG low, IgA low

A

HyperIgM syndrome

37
Q

CD4+ normal, CD8+ normal, B cell normal, IgM normal/low, IgG low, IgA low

A

Common variable immune deficiency

Y5 Immunology (4 decks)

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