Paediatric Immunology 2 Flashcards
How might you treat CGD?
- Cotrimoxazole prophylaxis (decreases serious infections from annually to Q3.5y)
- Itraconazole prophylaxis
- IFN-gamma
- BMT – depending on severity of clinical phenotype
How does neutropenia present clinically?
- Fever
- Aphthous stomatitis
- Gingivitis
Deficiency of which complement component is most associated with severe pyogenic infections?
C3 - common final pathway
Which cells are implicated in allergic disease?
- Th2 T cells
- Eosinophils
Which cytokine drives eosinophil production?
IL-5
Which cytokine has a role in inducing a generalised anti-viral state of cellular metabolism in other cells?
Interferon 1 (alpha and beta)
What does alpha-1 antitrypsin do?
Prevents tissue destruction
What diseases are associated with NALP3 mutations?
- Familial cold urticaria
- Muckle-Wells
- Neonatal onset multisystem inflammatory disease
It is important to avoid which medication in hereditary angioedema?
ACE inhibitors
What does exulizumab do?
Monoclonal C5a antibody, useful for PNH and aHUS
What is a Type 1 reaction?
Immediate IgE mediated reaction e.g. anaphylxis, urticaria, angioedema, anaphylactic shock, bronchial asthma, rhinitis, conjunctivitis
What is a Type 2 hypersensitivity reaction?
Antibody mediated cytotoxic reaction e.g. immune haemolytic anaemia
What types of allergy do you do intradermal testing for?
Drug allergy
Insect venom allergy
What is a Type 3 hypersensitivity reaction?
Immune complex mediated e.g. serum sickness, vasculitis
When is tryptase highest?
Peaks 60-90mins after anaphylaxis, can be taken 15mins after, helpful up to 3 hrs but may be high for up to 5hrs
What autoantibodies are positive in polyarteritis nodosa?
None - trick question!
Associated with strep infection, Hep B, chronic hepatitis
What does AIRE actually do?
Induces expression of self-proteins in thymic medullary cells
Regulates central tolerance
How does toxic shock syndrome happen?
Bacteria produce a superantigen toxin that allows the nonspecific binding of MHC II with T-cell receptors, resulting in polyclonal T-cell activation
MHC class I pathway is for…?
- Sampling and processing proteins from the cytoplasm of somatic non APC cells
- Therefore if intracellular organisms invade cells and cause upregulation/production of unusual stuff, cytotoxic T cells (CD8) can kill it
- If the intracellular organism downregulates MHC then NK cells can kill it
What type of reaction is Steven-Johnson Syndrome?
- Type IV hypersensitivity
- drug or its metabolite stimulates cytotoxic T cells (i.e. CD8+ T cells) and T helper cells (i.e. CD4+ T cells) to initiate autoimmune reactions that attack self tissues
What is the difference between SJS and TEN?
- TEN more severe
- >30% of body
Why don’t B cells develop in Bruton’s (XLA)?
Because there is no bruton tyrosine kinase i.e. no SIGNALLING (critical signalling molecule)
What would you expect from a TH2 response?
High IgE
High eosinophils
Raised IL4
Raised IgG4
Diseases with inflammasome reaction respond to blockade of….
IL-1 which is anakinra
Monoclonal antibody to IL4 targets which T cells…?
TH2
Eosinophilic granulomatosis with polyangiitis (EGPA or Churg-Strauss syndrome) is characterized by….
Asthma, eosinophilia, and systemic vasculitis of multiple organs
The anaphylotoxins are….
C3a, C4a, and C5a
Cyclosporin targets…
- T-cells
- Binds to the cytosolic protein cyclophilin (aka immunophilin) -> inhibits calcineurin -> less transcription of interleukin 2 -> T Cells not activated
Type 1 Interferons are associated with which sort of infective organism?
Viruses
e.g. IFN-α and IFN-β
What drugs do we avoid in C1 deficiency?
ACEI
Oestrogen
Acute renal transplant rejection is mediated by…
Direct recognition of foreign MHC (HLA) by T cells
Exact HLA match probabiity between siblings…
25%
Which interleukin is needed for T-cell development?
IL-2
CRP production is stimulated by which cytokine?
IL-6
What are the laboratory and imaging findings associated with ataxia-telangiectasia?
- High AFP
- low Ig
- white blood cell chromosome fragility
MRI would show cerebellar volume loss, and compensatory enlargement of the fourth ventricle
What % of children outgrow peanut allergy?
20%-25%
SJS/TEN is which type of immune reaction?
Type IV
Serum sickness is which type of immune reaction?
Type III
What is the treatment for anaphylaxis?
IM - adrenaline 0.01 ml/kg of 1:1000
IV - adrenaline 0.01 ml/kg of 1:10000 or 0.01mg/kg
Increased allergy is associated with…
- Decreased allergen and microbial diversity exposure
- Excessive use of antibiotics in first 2 years of life can change gut flora and therefore modulate allergy
You can help prevent atopic dermatitis by…
- Taking probiotics during pregnancy
- Applying bland moisturizer in infancy
What are the complement fixing antibodies?
- IgG and IgM
HOT T Bone sTEAk acronym stands for…?
Interleukin functions
- IL-1 fever
- IL-2 for T cell stimulation
- IL-3: Bone marrow stimulator (sim to GM-CSF)
- IL-4: IgE (class switching from IgG), B cell growth
- IL-5: IgA, eosinophils
