Immunology Flashcards
What are SPUR infections? What do they indicate?
Serious, Persistent, Unusual, Recurrent
Indicate immune deficiency
What is the main hallmark of immune deficiency?
Recurrent infections
Primary immune deficiencies are common. True/False?
False
Rare! Secondary immune deficiencies are common
Risk of infection ______ as neutrophil count increases
Decreases
How can failure to produce neutrophils arise?
Failure of stem cell differentiation
Failure of neutrophil maturation
What is Kostmann syndrome?
Rare autosomal recessive disorder; congenital neutropenia
Clinically presents as (recurrent) infections 2 weeks after birth
What is leukocyte adhesion deficiency?
Rare primary immune deficiency where neutrophils fail to bind to endothelial markers - cannot find where infection is!
Genetic defect in CD18
What is chronic granulomatous disease?
Failure of oxidative killing due to inability to generate oxygen free radicals
Name an important related side effect of anti-TNF therapy
Reactivation of latent TB
In congenital neutropenia, neutrophil count is normal. True/False?
False
Low or absent
Is there pus formation in congenital neutropenia?
No
In leukocyte adhesion deficiency, neutrophil count is low during infection. True/False?
False
It is high
Is there pus formation in leukocyte adhesion deficiency?
No
In chronic granulomatous disease, neutrophil count is normal. True/False?
True
Would be raised in the acute stage but not once granuloma has formed
Is there pus formation in chronic granulomatous disease?
Yes
Give examples of definitive management of phagocyte deficiencies
Bone marrow transplant, gene therapy
What cells do T cells arise from?
Haemopoetic stem cells in bone marrow
Defects in stem cell differentiation in haemopoetic cells causes which fatal condition?
Reticular dysgenesis
What is Severe Combined Immunodeficiency (SCID)?
Failure of production of lymphocytes
What are some key clinical phenotypes of SCID?
Unwell by 3 months
Diarrhoea
Failure to thrive
Early death
Why does SCID present only after 3 months of age?
Maternal IgG protects the infant up to this point
In X-linked SCID, which receptor is mutated?
IL2 receptor
What is DiGeorge syndrome?
Failed development of the thymus
“Funny looking kid”
Which chromosome is deleted in DiG syndrome?
22q11
In DiG syndrome, the thymus fails to develop. What is the consequence of this?
Low/no T cells can mature (thus low T cell numbers)
What is hypogammaglobulinaemia?
Failure to produce mature B cells
What is common variable immunodeficiency?
Low IgG, IgA and IgE
Leads to recurrent infections, often autoimmune
Which type of hypersensitivity reaction do allergic diseases come under?
Type 1
Define what is meant by allergy
IgE-mediated response to an external antigen
Describe the hygiene hypothesis
Decrease in infectious exposure in early life predisposes to increased sensitivity/predisposition to allergic stimuli
Allergic reactions typically take a few hours to develop. True/False?
False
Can be from within minutes to a couple hours