RA, osteoarthritis, ankylo Flashcards
(164 cards)
In gout - depositions of what component?
Monosodium urate crystals
What is a risk factor for hyperuricemia?
increased purine metabolism
what is a risk factor for gout?
elevated uric acid levels
What is important enzyme in purine synthesis?
phosphoribosyl pyrophosphate (PRPP) synthetase
What produces PRPP synthetase?
activated ribose
What component is needed for de novo synthesis of purine and pyrimidine nucleotides?
activated ribose
activated ribose is used in ………….. and ………… synthesis.
de novo purine and pyrimidine synthesis
What mutation in what structure leads to increased production and degradation of purines?
Activating mutation involving PRPP synthetase
activating mutation in PRPP synthetase cause …………….. activation of purine synthesis pathway.
feed-forward
What is result of feed-forward activation of the purine synthesis pathway?
More purine molecules will undergo degradation, resulting in hyperuricemia and increase risk of gout
What joints most commonly in acute gouty arthritis?
First metatarsophalangeal joint or knee
acute gouty arthritis symptoms develops within ………..
rapidly over 24h
manifestation (3) of acute gouty arthritis?
swelling, erythema and exquisite tenderness
What method is used for diagnosis of acute gouty arthritis?
Joint aspiration –> needle-shaped, negatively birefringent crystals under polarized lamp
What are primary immuno cells in acute gouty arthritis?
neutrophils
Pathophysio of acute gouty arthritis?
Neutrophils –> phagocytosis of urate crystals –> release of various cytokines and inflammatory mediators –> further neutrophils activation and chemotaxis –> positive feedback loop that amplifies the inflammatory response
What is first therapy in acute gouty arthritis?
NSAIDs
Why NSAIDs used in acute gouty arthritis as primary agent?
inhibit prostanoid biosynthesis (prostaglandins, prostacyclin, thromboxane) –> broad ant-inflammatory effect that includes INHIBITION OF NEUTROPHILS
Why patients may be contraindicated for NSAIDs?
peptic ulcers, renal impairment
What use in acute gouty arthritis if patient cannot use NSAIDs?
Colchicine
What is effect of colchicine on neutrophils?
impairs migration and phagocytosis by interfering with microtubule formation
What mechanism by colchicine decrease neutrophils activation?
Colchicine decreases tyrosine phosphorylation in response to monosodium urate crystals, resulting in decreased neutrophil activation
What cells are targeted in therapy of acute gouty arthritis?
neutrophils
What is a central mechanism involved in precipitating an acute gouty attack?
NEUTROPILS!!!!