Immune Modulation Flashcards
1
Q
Steroids
A
- Glucocorticoid steroids
Actions
- Block phospholipase A2, so there is less prostaglandin production and less inflammation
- Blocks phagocyte recruitment and phagocytosis
- Keeps lymphocytes sequestered in lymphoid tissue (T cells > B cells)
Effects on blood:
- neutrophilia
- lymphopenia
2
Q
Cyclophosphamide
A
- Alkylating agent - alkylates guanine on DNA, preventing DNA replication
- Acts on B-cells more than T-cells
- Used in antibody-mediated disease e.g. SLE
- Side-effects - haemorrhagic cystitis can occur due to toxic metabolite acrolein
3
Q
Azathioprine
A
- Metabolised in the liver to 6-mercaptopurine
- This is a purine analogue, blocks de novo purine synthesis
- Affects T-cells more than B-cells
Indications
- Autoimmune disease e.g. SLE
- Autoinflammatory disease e.g. Crohn’s
Side-effects
- Some people can get complete bone marrow suppression - associated with TPMT polymorphism
- They cannot metabolise azathioprine, so it builds up in bone marrow and causes pancytopenia
4
Q
Mycophenalate
A
- Binds de novo guanosine analogue synthesis
- Main use is post-transplant
Main worry - risk of reactivated infection
- HSV reactivation
- JC virus + progressive multifocal leukoencephalopathy
TERATOGENIC
5
Q
Plasmapheresis
A
- Patient’s own blood is passed through a cell separator and the pathogenic antibody is removed
- Plasma is either re-infused, or replaced with albumin
- Give with immunosuppressive agent, as there is usually a rebound increase in antibody production
Indications
- Goodpastures disease
- Myasthenia gravis (severe acute disease)
- Severe transplant rejection
6
Q
Calcineurin inhibitors
A
Ciclosporin and Tacrolimus
- Bind to calcineurin, preventing T-cell signalling
- This blocks activation of NFATc and IL-2 expression
- Used in psoriasis and severe eczema
Side effects
- Nephrotoxic
- Hypertension
- Diabetes (tacrolimus > ciclosporin)
- Can be neurotoxic
- High doses of ciclosporin can cause gum hypertrophy, hirsutism
7
Q
JAK 2 inhibitors
A
- Block JAK2-STAT pathway
- This is involved in cytokine inflammation
- Effective in rheumatoid arthritis
8
Q
Apremilast
A
PDE4 (phosphodiesterase 4) inhibitor
- There is increased cAMP production
- Increased Protein Kinase A (PKA)
- Decreased cytokine production and inflammation
- Used in psoriasis and psoriatic arthritis
9
Q
Rabbit anti-thymocyte globulin
A
- Human thymocytes injected into rabbits
- Rabbits produce a number of thymocyte antibodies
- Serum containing anti-thymocyte antibodies can be injected into humans
Effects
- T-cell depletion
- inhibits T-cell activation
- Inhibits T-cell migration
Uses
- NOT SPECIFIC
- Can be used in allograft rejection e.g. renal/heart transplant
Side-effects
- Infusion reactions
- Leukopenia
- Malignancy
10
Q
Basiliximab
A
- Anti-CD25 antibody
- Targets IL-2, so IL-2 cannot acts on T-cells
- Blocks T-cell proliferation and function
Uses
- prophylaxis for allograft rejection (given before and after transplant surgery)
Side-effects
- Infusion reactions
- Leukopenia
- Malignancy
11
Q
Abatacept
A
- Fusion protein of CTLA4 and human IgG Fc
- Blocks binding of CD80 and CD86 on APCs, with T-cells
- used in rheumatoid arthritis
Side-effects
- Infusion reactions
- Leukopenia
- Malignancy
12
Q
Rituximab
A
- Anti-CD20 antibody
- Depletes B-cells, but not plasma cells
Uses
- Lymphoma
- Rheumatoid arthritis
- SLE
Side-effects
- Infusion reactions
- Infection, especially JC virus and PML
- Exacerbation of CVD
13
Q
Natalizumab
A
- Anti-alpha 4 integrin antibody
- Alpha-4 is part of an integrin complex with B1/B7
- The integrin complex is involved in leukocyte arrest, adhesion and migration
- Natalizumab block leukocyte migration to tissue
Uses
- Highly active relapse-remitting MS
- Crohn’s disease (in the past, not anymore)
Side-effects
- Infusion reactions
- Infection - HIGH RISK of JC virus and PML
- hepatotoxic
- Malignancy
14
Q
Tocilizumab
A
- IL-6 antibody
- Wide immunosuppressive effect, as IL-6 is involved in macrophages, T-cells, B-cells and neutrophils
Uses
- Castleman’s disease (IL-6 producing tumour)
- Rheumatoid arthritis - very effective
Side-effects
- infection
- hepatotoxic
- dyslipidaemia
- malignancy
15
Q
Antibody replacement therapy
A
- Human normal Ig is derived from pools of 1000s of donors
- Can be given as SC injection every 3-4 months
- Used in primary antibody deficiency (e.g. Bruton’s) and secondary antibody deficiency e.g. MM