lecture 30 - immunodeficiency

Question 1

What is the difference between primary and secondary immunodeficiency?

Answer 1

Primary: genetic/congenital, deficiency which results in disease
Secondary: acquired, more common

Question 2

What is chronic granulomatous disease

Answer 2

Defects in reactive oxygen intermediates → impaired killing, recurrent intracellular bacterial and fungal infections
Primary innate immunity defect

Question 3

What is complement immunodeficiency

Answer 3

Impared immune complex clearance → inflammation, phagocytosis and lysis
C3b coated immune complexes bund B3b receptor on phagocytic cells → lack of C3b receptor → reduces effective cytosis
Primary innate immunity defect

Question 4

What is digeorge syndrome, how does it compare to bruton’s disease?

Answer 4

Brutons
X linked agammagloblinemia
Failure in B cell maturation due to defect in bruton tyrosine kinase
Absence of antibodies in the blood
Few or no B cells and small lymphnodes
Problems from 3 months

Digeorge
Failure of thymus development → absence of T cells
Susceptible to viral, protozoan and fungal infection

Vaccines are life threatening

Question 5

What is hyper-IgM syndrome

Answer 5

Defect in T cell dependent B cell activation
Defective switching of B cells to IgG and IgA, → compensatory increase in IgM
Mutation in CD40 ligand
Susceptibility to infection by intracellular microm Pneumocystis Carinii

Question 6

What is CVID

Answer 6

Common variable immunodeficiency
Decrease in IgG and IgA
Variabel failures of B cells maturation into plasma cells (hypogammaglobulinemia)
IV immunoglobulin treatment

Question 7

Describe combined B and T cell immunodeficiency

Answer 7

Autosomal recessive disease

Adenosine daminase deficiency → accumulation of toxic deoxyadenosine for lymphocyte maturation

Question 8

What is SCID

Answer 8

Severe combined immuno-deficiency
Mutations in rAG 1 and 2
Failure of B and T cell maturation, susceptible to all types of infection at 3 months
Live vaccines fatal and ineffective
Treatment via bone marrow transplant

Question 9

What is MHCII deficiency

Answer 9

Defective class II MHC expression
Bare lymphocyte syndrome 
Significant reduction in CD$ T cells  → deficiency in antibody respons (T cell dependent antigens) → fatal unless treated with bone marrow transplant

Question 10

Describe acquired HIV and its clinical progression

Answer 10

HIV infections in macrophage and Th cells occurs when gp120 binds to both CD4 and CCR5 (MIP chemokine ligand) OR CXCR4 (CXCL12 chemokine receptor)
Gp41 required for virus fusion
HIV causes depletion of CD4 T cells, leading to AIDS eventually

Question 11

Compare and contrast the different viral agents that cause cancer

Answer 11

Human T cell leukemia virus 1 → RNA
HTLV-1
Adult T cell leukemia or lymphoma

Human herpesvirus 8 → DNA
HHV-8
Kaposi’s sarcoma

Human papillomavirus → DNA
HPV
Cervical carcinoma

Hepatitis B and C → DNA
HBV and HCV
Liver carcinoma

Epstein-Barr virus → DNA
EBV
Burkitt’s lymphoma and nasopharyngeal carcinoma