Immunosuppression Flashcards
What is RA
Inflammatory issues round synovium = pannum. Systemic symptoms. erosive damage -> disability
• An autoimmune multi-system disease • Fairly common: UK prevalence 1%
• Initially localized to synovium
• Inflammatory change and proliferation of synovium (pannus) leading to dissolution of cartilage and bone
Describe the pathogenises of RA
Hyperactive immune system. Imbalance between pro and anti inflammatory. Get auto rheumatic diseas ehwen pro inflammatory mroe active than anti. Il-6, il-1, tnfa. Over expression of metalloproteinases leds to inflammation of joints
What are the symptoms of RA
Clinical criteria
• Morning stiffness >=1 hour
• Arthritis of >= 3 joints
• Arthritis of hand joints
• Symmetrical arthritis
• Rheumatoid nodules
Non-clinical criteria
• Serum rheumatoid factor/Anti-CCP antibodies
• X-ray changes
More joints inflamed = more severe symptoms. Nodules late bc treated early. Acpa
X ray changes typically abt 6mths-1 year into disease.
Regulation can affect children a young as 4.. a
What are the treatment goals for RA
Symptomatic relief
Prevention of joint destruction
Describe teh treatment strategy for RA
- Early use of disease-modifying drugs
- Aim to achieve good disease control
- Use of adequate dosages
- Use of combinations of drugs
- Avoidance of long-term corticosteroids
Describe sle
Ss, No organ is spared. Can affect any organ - widespread. A disease of women f childbearing age.
Describe asuclitis
LFTS - leucocytic infiltrates, fibrinoid nicrocsis , thrombosis
What are he treatment goals in sle ad vasculitis
- Symptomatic relief e.g arthralgia, Raynaud’s phenomenon
- Reduction in mortality
- Prevention of organ damage
- Reduction in long term morbidity caused by disease and by drugs
What are some immunosuppressants
- Corticosteroids • Methotrexate
- Azathioprine
- Ciclosporin
- Tacrolimus
- Mycophenolate mofetil • Leflunomide
- Cyclophosphamide
Describe teh moa do corticosteroids
• Prevent interleukin IL-1 and IL-6 production by macrophages
• Inhibit all stages of T-cell activation
Heatshcok protein complex - glucocorticoid interacts with this - goes into nucleus - chin of events - not very targeted
What are steroid side effects
Teroi side effects - many systems. Side effects - accelerates old age - cataracts, MI, stroke, raised cholesterol, tru cal obesity, buffalo hump, osteoporosis, diabetes
What are demands
Non-biologics (cheaper but just as effective)
• Sulphasalazine
• Hydroxychloroquine
Biologics
• Anti-TNF agents
• Rituximab
• IL-6 inhibitors, JAK inhibitors
What is azathioprine
• SLE & vasculitis -as maintenance therapy
• RA–veryweakevidence
• Inflammatory bowel disease
• Bullous skin disease
Atopic dermatitis
• Many other uses as ‘steroid sparing’ drug - This allows to cu short the exposure to steroids if used first
Describe the pd of azathioprne
- 6-MP is metabolized by thiopurine - Tpmt converts aaa to 6mp methyltransferase (TPMT)
- TPMT gene highly polymorphic
- Individuals vary markedly in TPMT activity
- Low/absent TPMT levels = Risk of myelosupression
- Therefore test TPMT activity before prescribing
Describe teh azthiprine moa
• Cleaved to 6-mercaptopurine (6-MP)
• anti-metabolite decreases DNA and RNA synthesis
Ss
Suppress immunity. Decreases dna and rna synthesis. If you shut down synthesis , inflammation reduces
What are the side effects of dmards
Bone marrow suppression – Monitor FBC • Increased risk of malignancy – Esp transplanted patients -NHL • Increased risk of infection • Hepatitis – Monitor LFT
Nausea dn vomiting
Describe calcineurin inhiitors in practise
• Ciclosporin & tacrolimus widely used in transplantation
• Also for atopic dermatitis & psoriasis
• Not often used in rheumatology -renal toxicity
• Check BP and eGFR regularly
• Multiple drug interactions are possible (Cytochrome P-450)
Tacrolimus in use. Anti rejection. Circle good for skin problems - but can make gums swell. Can elevate k+.
Inhibi cytochromsp450. Get more drug bc not as metabolised /
What are the moas of cyclosporine and tacrolimis
• Active against helper T-cells, preventing production of IL-2 via calcineurin inhibition
• Ciclosporin binds to cyclophilin protein
• Tacrolimus binds to tacrolimus-binding protein
• Drug/protein complexes bind calcineurin
• Calcineurin exerts phosphatase activity of activated T- cells then nuclear factor migration starts IL-2 transcription
Hot t bone steak. Hot - il1 causes fever. T - interleukin 2 stimulate T cell. Bone - il3 stimulate bone marrow. Steak. EA - 4 and 5 act on ige and igg
When is mycophenolate mofetil used
- Primarily in transplantation
- Good efficacy as induction and maintenance therapy for lupus nephritis/Vasculitis maintenance
- In transplantation medicine: Mycophenolic acid may be monitored
What are the moa of mmf
• Is a prodrug derived from fungus Penicillium stoloniferum
• Inhibits inosine monophosphate dehydrogenase (required for guanosine synthesis)
• impairs B- and T-cell proliferation
• spares other rapidly dividing cells
(due to guanosine salvage pathways in other cells)
What are the side effects ofmmf
- Most common include nausea, vomiting, diarrhea
* Most serious is myelosuppression
What are the effects and indications of cyclophosphamide
Cytotoxic Agent :
Alkylating agent -cross links DNA so that it cannot replicate
Many immunological effects:
– suppresses T cell activity
– suppresses B cell activity
Indications:
– Lymphoma, leukaemia, solid cancers
– Lupus nephritis
– Wegener’s granulomatosis (ANCA-vasculitis)
Starts working in abt 10 days. Cancer doses big eg 5g. In rheumatology, big drugs 1.5g. Induce remission. But cant keep giving it - can cause cancer.. once remission induced, pull out, give mm or aza instead (maintenance)
Describe the pd of cyclophsphamide
- Is a prodrug
- Converted in the liver (cytochrome P450) to active forms
- The main active metabolite is 4-hydroxycyclophosphamide
- 4-hydroxycyclophosphamide exists in equilibrium with its tautomer, aldophosphamide.
- Most of the aldophosphamide is oxidised to make carboxyphosphamide. A small proportion of aldophosphamide is converted into phosphoramide mustard (main active metabolite)
What needs to me given with cyclophosphamide and why
• Cyclophosphamide is excreted by the kidney
• Acrolein, another metabolite is toxic to the bladder epithelium and can lead to hemorrhagic cystitis
• This can be prevented through the use ohydration and/or Mesna.
Mensa mopes up acrol