June6 M1-Crystal Arthropathies

Question 1

diseases related to uric acid

Answer 1

• hyperuricemia
• gouty arthritis
• urolithiasis (uric acid stones in kidney)
• chronic interstitial nephropathy (CKD caused by uric acid)

Question 2

hyperuricemia definition + treatment goal

Answer 2

serum conc above 360 umol/L. target = under that

Question 3

gouty arthritis is what

Answer 3

• acute joint or bursa inflam (arthritis or bursitis)

- urate deposition (tophus) in periarticular region or soft tissues

Question 4

ways we get uric acid in our body

Answer 4

• endogenous purine synthesis (uric acid is a purine) from tissue breakdown and turnover
• food

Question 5

uric acid eliminated by what organs (how we get it out)

Answer 5

67% kidneys

33% gut

Question 6

(IMP) general causes of the problem in hyperuricemia (prod vs excretion) is what

Answer 6

90% are underexcreters

10% are overproducers

Question 7

(IMP) charact of the pathway to make uric acid (uric acid metab)

Answer 7

• all starts with guanine or adenine
• diff steps down pathway
• some feedback loops in pathway to slow it down if making too much uric acid

Question 8

(IMP) enzyme involved in making most of the steps of uric acid metabolism

Answer 8

PRPP synthetase

-if overactive, get too much uric acid prod

Question 9

(IMP) 2 last steps of uric acid metab + enzyme involved

Answer 9

• make hypoxanthine into xanthine
• make xanthine into uric acid
• done by XANTHINE OXIDASE*

Question 10

(IMP) charact of steps regulated by xanthine oxidase

Answer 10

irreversible steps (the 2 last)

Question 11

(IMP) enzyme involved in feedback loop in the uric acid metab pathway (like PRPP) and that makes the pathway overactive if it’s defective

Answer 11

HGPRT. 2 types of defects

• partial deficiency on top of PRPP overactivity
• severe HGPRT deficiency (Lesch-Nyhan syndrome)

Question 12

(imp?) most common drug for hyperuricemia

Answer 12

xanthine oxidase inhibitors

Question 13

hyperuricemia caused by PRPP overactivity and HGPRT underactivity (pathway, enzyme related) is what type

Answer 13

overproducers (10% of hyperuricemia)

Question 14

some causes of impaired uric acid excretion (the secondary ones, other than primary idipathic)

Answer 14

• diminished renal function
• lactic acidosis in diabetes (promotes hyperuricemia and a lot of uric acid reabso in the kidney)
• metabolic syndrome, overweight

Question 15

complications of hyperuricemia

Answer 15

• renal failure
• urolithiasis
• destructive arthropathy
• recurrent gout (pain attacks)
• cardiovascular disease and CKD

Question 16

gout is what

Answer 16

abrupt extreme pain attacks lasting hours

Question 17

why treat gout

Answer 17

• gout = higher risk of all cause mortality including CVD

- prevent destructive arthritis (overhanging edges)

Question 18

4 states of gout

Answer 18

• asymptomatic hyperuricemia
• acute flares (recurrent attacks of arthritis)
• intercritical (between) flare period
• advanced gout (kidneys, stones)

Question 19

one important cause of hyperuricemia not to forget

Answer 19

medications that raise uric acid level

-one common = baby aspirin

Question 20

important pathologic events for development of acute crystal induced synovitis in gouty inflammation

Answer 20

influx of neutrophils

Question 21

treatment approach for gout

Answer 21

• treat flares with NSAIDs or colchicine. CS also possible
• urate-lowering therapy (like xanthine oxidase inhibitors) for more severe cases. would treat to reach under 360 umol per L