Edmead S1 Flashcards
In the innate immune system cytokines are produced mainly by what?
Mononuclear phagocytes in response to infectious agents
Chemokines enhance extravasation- what is this?
The leakage of fluid out of its container
In the adaptive immune system- Th1 cells secrete what to stimulate macrophages and cytotoxic T cells causing tissue damage
IFN-gamma
In the adaptive immune system- Th2 cells released what type of cytokines and give an example
Anti inflammatory
IL-4
Which two cytokines increase leukocyte adhesion to endothelium
TNF
IL-1
Even though they are first line, why aren’t NSAIDs very good in RA?
Because they work by inhibiting COX so less prostaglandins and prostaglandin isn’t that important in chronic inflammation
Name 6 DMARDs
Methotrexate Sulfasalazine Gold Penicillamine Hydroxychloroquine Leflunomide
What’s the mechanism of action of methotrexate
Suppresses IL1 induced IL6 so decreased synovial cell proliferation and reduced reactive O2 species
What does lysosomotropic mean
Accumulates in lysosomes of cells in the body
Where are endogenous corticoids released from?
Adrenal cortex
Name a mineralocorticoid and what does it effect
Aldosterone
Affects water and electrolyte balance
Give two examples of glucocorticoids
Hydrocortisone and corticosterone
What do glucocorticoids affect?
Carbohydrate and protein metabolism
Anti inflammatory and immunosuppressive effects
Name a disease that results from deficiency in steroids
Addison’s disease
Name a syndrome that results from excess glucocorticoid
Crushings syndrome
Name a syndrome as a result of excess mineralocorticoid
Conns syndrome
What does the HPA axis stand for
Hypothalamic-pituitary-adrenal axis
In the HPA axis what’s the hormone released from the hypothalamus to the pituitary
Corticotrophin releasing hormone
In the HPA axis what’s the hormone released from the pituitary to the adrenals
Adrenocorticotrophic hormone
Name 3 key metabolic side effects of steroids
Osteoporosis
Diabetogenic-obesity
Mineralocorticoid effects (Na/H2O retention, hypertension, oedema, CV events)
What are TNF and IL-1 and what are they involved in?
Both proinflam cytokines involved in cell proliferation (both) and apoptosis (TNF)
What is TNF and IL-1’s primary beneficial function
Beneficial activation of innate immune system
Are TNF and IL-1 self induced?
Yeh they bind to receptor and up regulate
What are TNF and IL-1 produced by
LPS-activated monocytes/macrophages
How many forms of interleukin-1 are there?
2 forms
Alpha
Beta
Try or false: IL-1 alpha is the most common circulating form
False it’s mainly cytosolic or membrane bound
IL-1 is synthesised as what and by what?
As precursors and cleaved by interleukin-1 converting enzyme (ICE) also known as Caspase 1
What are ICE inhibitors and are they effective
Anti inflammatory agents
NO
What’s the main purpose of inflammation
Bring cells from blood to site of infection
What is thought to cause RA
Initiating antigen is unknown but disease often follows an infection
What initiates and sustains disease through recognition of autoantigen?
CD4+ Tcell
Give two examples of likely autoantigens in RA
Collagen and other cartilage components
Chronic inflammation is mediated largely by what?
CYTOKINES
What are cytokines?
Small proteins secreted by cells of the immune system
Cytokine function can be what three things
Autocrine
Paracrine
Endocrine
Give 4 key effects of cytokines
Induce T&B differentiation
Activation of macrophages
Cellular migration
Apoptosis
Chemokines enhance what?
Extravasation
TNF and IL-1 increase leukocyte adhesion to what?
Endothelium
Th1 cells secrete what to do what?
IFNg to stimulate macrophages and cytotoxic T cells causing tissue damage
What do Th2 cells release and give an example
Anti inflammatory cytokines e.g IL4
Give two examples of pro inflam cytokines
TNF
IL-1
Give two examples of anti inflammatory cytokines
IL4
IL10
What’s the TNF IL-1 cycle
TNF/IL-1 act on macrophages to stimulate Thelper to promote differentiation into Th1 which promotes more IFNg which feeds back on to macrophages to increase inflam
Pain and swelling in RA is due to what
Infiltration of white blood cells
What’s first line in treating RA
NSAIDs
NSAIDs have 3As what are they
Analgesia
Anti inflam
Antipyretic
How do NSAIDs work
Block cyclooxygenase which makes PG which causes pain and swelling
What’s a key limitation of NSAIDs in RA
Target reducing PG but this isn’t a key problem in chronic inflammation
What’s second line to treat RA
disease modifying rheumatic drugs DMARDs
Are DMARDs slow acting?
Yes see effects after about 3-4 weeks
What’s usually the first DMARD recommended?
Methotrexate
How does methotrexate work?
It’s a folate antagonist- blocks DNA synthesis therefore blocks cell proliferation via inhibition of degydrofolate reductase
What does IL-6 do and what potentially suppresses it via IL-1
IL-6 drives synovial cell proliferation and reduces reactive oxygen species
MTX might stop it
What’s the problem with methotrexate
Targets enzyme which can actually change and become resistant or cells may use alternative pathway. Also toxic
What’s sulphasalazine?
Is a DMARD acts as an antibiotic and anti rheumatic
What’s penicillamine
DMARD prevents maturation of newly synthesised collagen- decreased joint swelling, RF, and concentration of acute phase proteins
What’s a key side effect of penicillamine
Thrombocytopenia (low platelets)
How does hydroxychloroquine work?
Stabilises lysosomes so reduces release of reactive oxygen species inhibits phospholipase A2 (PLA2)
Reduces cytokine transcription
What’s Leflunomide
Newest DMARD targets enzymes involved in DNA synthesis and may suppress B cell activity and reduce RF
What’s third line in RA
Steroids
How do steroids work
Work in nucleus
Effect gene transcription
Block pro inflam cytokine production
Why does the body rely on exogenous steroids when they’re given them?
Cos they suppress the endogenous steroids
Can steroids work at all stages of the inflammatory response?
Yes
Within the nucleus, steroids act on what to affect gene transcription
Proteins like AP-1 and NFkB that affect gene transcription
Which form of IL-1 is the biggest problem that we want to target
Beta form
Where is IL-1 synthesised?
In the micro tubules
IL-1 increases synthesis of what?
COX-2 and iNOS
IL-1 increases expression of what
VCAM and ICAM (selectins and adhesion molecules that enhance extravasation)
How does C5a relate to IL-1
C5a increases IL-1 mRNA
True or false:
Increase Tcells
Increase IFNg
Increase IL-1
TRUE
True or false: Increase CD40L Increased BCells Induces more IL-1b Increased extravasation
TRUE
IL-1 receptors are members are member of what superfamily
Ig superfamily
How many types of IL-1 receptor are there?
TWO:
Type 1 present on most cells (main receptor)
Type 2 mainly B cells, decoy receptor
How many forms of TNF are there and which one is the main form?
Two forms
TNF alpha is main
What type of receptor is the TNF receptor
Homotrimers
What can cleave TNF from surface?
Metalloproteinases
How many types of TNF. receptor are there and on which cells are they present?
TWO
all cells except RBC
There are two TNF receptors.. Which one is responsible for cell growth AND cell death
TNFR 1
How many receptors do you have to block in the TNF receptor in order to actually block it
At least two
Almost all therapeutic antibodies we use are polyclonal. True or false?
FALSE it’s monoclonal
What’s the drug name of anti ICAM
Enlinimab
What was the problem with Enlinimab
Patients developed immune complexes which can block vessels
Name the chimeric antibody
Inflixab (anti TNF)
How do you minimise immunogenic reactions with infliximab?
Give with MTX if tolerated
Name a humanised antibody
Certolizumab
Name two fully humanised antibodies
Adalimumab
Golimumab
What’s the problem with soluble receptors?
They are cleared very quickly so need repeat injections
How can we extend circulatory lifecycle of antibodies
Dimerise two soluble receptors using PEG
Give two examples of chimeric fusion proteins
Lenercept
Etanercept
What’s anakinra?
Recombinant non glycosylation form of IL-1RA
Injected into joints via viral vector
Name an anti-B cell therapy in RA
Rituximab
How does Rituximab work?
B cell depleting monoclonal anti-CD20 antibody- causes B cell apoptosis
Name an anti-T cell therapy in RA
Abatacept
Name an IL-1 receptor antagonist
Anakinra
Name a humanised monoclonal antibody against IL-6 receptor
Tocilizumab
Name a janus kinase 3 inhihitor used in RA
Tofacitinib