Immunosuppression Flashcards
What % of the population does RA affect?
1%
What is the pathogenesis of RA?
Proinflammatory agents outweigh antiinflammatory agents.
IL-1 + IL-6 + TNF alpha > IL-4 + TGF beta
How do we treat RA?
Target against proinflammatory agents
What are the aims of treatment of RA?
Symptomatic relief and prevention of joint destruction
What are the treatment goals in SLE and vasculitis?
Symptomatic relief, reduce mortality, prevent organ damage, and decrease long term morbidity caused by disease and by drugs.
What immunosuppressants can we use?
Corticosteroids Azathioprine Ciclosporin Tacrolimus Mycophenolate mofetil
What DMARDs can we use?
Methotrexate Sulphasalazine ANti-TNF agents Rituximab Cyclophosphomide
How do corticosteroids work? (MoA)
Prevent IL-1 and IL-6 production by macrophages.
Inhibits all stages of T cell activation across all systems.
What are the side effects of steroids?
H&N - aggravate epilepsy, schizophrenia, exopthalmos, facial erythema, glaucoma, insomnia, corneal thinning, headaches,
Cardioresp - congestive HF, hiccups
GI - abdo distension, acute pancreatitis, dyspepsia
Systemic - bruising, hirsutism, hypercholesterolaemia, hyperhidrosis, hyperlipidaemia, impaired healing, thin skin, bruise easily.
Other - amenorrhoea, candidiasis, cushings syndrome
And others.
What is azothioprine used for?
Maintenacnce therapy for SLE and vasculitis, and for difficult to treat IBD.
How is azothioprine metabolised?
To 6MP by TPMT
What is important to note about TPMT?
TPMT gene is highly polymorphic so everyone has different levels of activity. If those levels are low, high risk of myelosuppression.
What should we test before starting azothioprine?
TPMT activity level
What is 6MP?
6-mercaptopurine = antimetabolite that decreases DNA and RNA synthesis by inhibiting purine metabolism.
What are the ADRs for azothioprine?
Bone marrow suppression
Increased risk of malignancy esp. in transplant pts
Increased risk of infection
Hepatitis
What should be monitored with azothioprine?
FBC (myelosuppression)
LFTs (hepatitis)
What class of drug are ciclosporin and tacrolimus?
Calcineurin Inhibitors
What is calcineurin and why does it need inhibiting?
Enzyme with phosphatase activity which usually produces IL-2 with helper T cells. Drug/protein complexes bind to calcineurin to inactivate it.
What monitoring do pts on ciclosporin/tacrolimus need and why?
BP and eGFR - nephrotoxic!
What is mycophenolate mofetil used for?
Immunosuppression in transplantation, and in lupus nephritis.
What are the ADRs associated with mycophenolate mofetil?
Nausea
V&D
GI ulceration
Myelosuppression
How does mycophenolate mofetil work?
Inhibits monophosphate dehydrogenase to prevent guanine synthesis. This impairs B and T cell proliferation.