Immune Mod Therapies 2 Flashcards
What are corticosteroids?
Synthetic glucocorticoids based on naturally occurring steroids
NO mineralocorticoid axrtivity
What structures do corticosteroids have an effect on?
Prostaglandins
Phagocytes
Lymphocytes
What is corticosteroid effect on prostaglandins?
Corticosteroids inhibit phospholipase A2
Phospholipase A2 is usually converts phospholipids into arachidonic acid
AA is then converted to eicosainoids (prostaglandins, leukotrienes) by COX
Therefore by blocking phospholipase, no prostaglandins are produced, reducing inflammation
What is corticosteroid effect on phagocytes?
Decreases phagocytes to inflamed tissue (due to reduced signals to phagocytes)
Decreased phagocytosis
Decreased proteolytic enzymes
What is corticosteroid effect on lymphocyte function?
Lymphopoenia (sequestration of lymphocytes in lymphoid tissue)
Blocks cytokine gene expression
Decreased antibody production
Promotes apoptosis
What are side effects of corticosteroids?
Metabolic - central obesity, moon face, diabetes, lipid disorders, osteoporosis, hirsutism, adrenal suppression
Others - cataracts, glaucoma, peptic ulceration, pancreatitis, avascular necrosis
Immunosuppression
What do anti proliferative agents do?
Inhibit lymphocyte proliferation
What are examples of anti proliferative agents?
Cyclophosphamide
Mycophenolate
Azathioprine
Methotrexate
What is the MOA of antiprolif agents?
Inhibit DNA synthesis (Cells with rapid proliferation are most targeted)
What is the MOA of cyclophosphamide?
Alkylates guanine bases of DNA
Damages DNA and prevents cell replication
Affects B cells > T cells
At high dose, affects all cells with high turnover
What are major indications for cyclophosphamide=
Multisystem connective tissue disease
Vasculitis with severe end organ involvement
Anti-cancer agents
What are side effects of cyclophosphamide?
- Toxic to proliferating cells (bone marrow suppression, sterility, hair loss)
- Haemorrhagic cystitis (as ACROLEIN in excreted in urine)
- Malignancy (bladder cancer, harm cancer, non-melanoma skin cancer)
- Teratogenic
- PCP
What is the mechanism of Azathioprine?
Metabolised by liver to 6 mercaptopurine
Blocks de novo purine synthesis
Prevents DNA replication
Preferentially inhibits T cell activation and prolif
What are indications of azathioprine
Transplant
AI disease
Autoinflamm disease e.g. Chrons, UC
What are side effects of azathioprine?
Bone marrow suppression
Hepatotoxicity
Infection
Individuals with what polymorphism are susceptible to bone marrow suppression?
Thiopurine Methyl Transferase
What is MOA of mycophenolate mofetil?
Blocks de novo nucleotide synthesis
Prevents DNA replication
Prevents T cell> B cell proliferating
What is indications of mycophenolate mofetil?
Transplantation
AI diseaase
What are side effects with mycophenolate mofetil?
Bone marrow suppression
Teratogenic
Infection (HSV, mrogressive multifocal leukoencephalopathy)
What is the aim of plasmapheresis?
PLASMA EXCHANGE aka remove pathogenic antibodies
What occurs in plasmapheresis?
Patient’s blood is passed through a separator
Own cellular components are reinfused
Plasma is treated to remove Ig and then reinfused
What is the issue with plasmapheresis and how do you solve it?
Rebound antibody production (because even if you get rid of the antibodies, the plasma cells are still there)
GIVE anti proliferative agent to avoid this
What are Indications for plasmapheresis?
Severe antibody-mediated disease
e.g. good pastures, Myasthenia graves, transplant rejection
What is the MOA of calcineurin inhibitors?
Inhibit calcineurin > prevent T cell signalling > block IL2 production
What are examples of calcineurin inhibitors?
Ciclosporin
Tacrolismus
What are SE of calcineurin inhibitors?
nephrotoxicity HTN neurotoxic diabetogenic dysmorphic features
What should you monitor with calcineurin inhibitors=?
BP
Renal function
What is an example of a JAK inhibitor?
Tofacitinib (JAK1, JAK3)
What do
What does Tofacitinib do?
Interferes with JAK-STAT signalling
Influences gene transcription
Inhibits production of inflammatory molecules
What disease is Tofacitinib good for?
RA
What is an example of PDE4 inhibitor?
apremilast
What is MOA of PDE4 inhibitors?
PDE4 works in metabolism of cAMP
PDE4 inhibitors upregulate cAMP
cAMP activates PKA, which prevents activation of transcription factors
This leads to a decrease in cytokine production
What is anti-thymocyte globulin used for?
Allograft rejection
As it causes T cell depletion
What is basiliximab?
an antibody directed at CD25
What is basiliximab used for?
For prophylaxis of graft rejection
What does basiliximab target?
IL2 receptor (called CD25), alpha chain Leads to inhibition of T cell proliferating
Side effects of basiliximab
Infusion reaction
Infection
Concern of long term malignancy
how does methotrexate work
ANTI-FOLATE
inhibits dihydrofolate reductase, stopping DNA synthesis
what must you give with methotrex
folate supplement
what must you always measure before you prescribe azathioprine
Thiopurine methyl transferase aka TPMT
because people with this variant will be unable to metabolise azathioprine
what does rituximab do
blocks CD20 > depletion of mature B cells
how does natalizumab work
against a4 integrin
what disease does natalizumab work against
MS
list some Anti-TNFalpha antibodies
infliximab
adalimumab
certolizumab
golimumab
what is the MOA of etanercept
TNF alpha antagonist - mops up TNF alpha > ihibits TNF alpha
WHAT IS MOA of denosumab
antibody against RANKL
Normally, osteblasts produce RANKL. RANKL binds to RANK > osteoclast differentiation and function > increase bone resorption
So denosumab stops osteoclast function > reduces bone resporption
what are indications for denosumab
osteoporosis
give subcut every 6 months
what is a side. effect of denosumab
avascular necrosis of jaw
