Rheumatology: Crystal Arthropathies Flashcards Preview

Unit 4: Blood and Lymph > Rheumatology: Crystal Arthropathies > Flashcards

Flashcards in Rheumatology: Crystal Arthropathies Deck (43)
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1

The _____ are a group of diseases characterized by tissue deposition of monosodium urate (MSU) crystals due to hyperuricemia.

crystal arthropathies

2

Name the 4 manifestations of crystal arthopathies.

1. gouty arthritis
2. tophi (deposits of MSU)
3. gouty nephropathy
4. uric acid nephrolithiasis (kidney stones)

3

____ usually refers to acute or chronic arthritis 2a to MSU crystals.

Gout

4

Hyperuricemia without symptoms is referred to as _____, not gout.

asymptomatic hyperuricemia

5

What are the 4 stages of gouty arthritis?

1. asymptomatic hyperuricemia
2. acute gouty arthritis
3. intercritical gout
4. chronic tophaceous gout

6

What are the features of asymptomatic hyperuricemia?

elevated serum uric acid (>7.0mg/dL) w/o gouty arthritis, tophi, or uric acid nephrolithiasis

7

What are the features of acute gouty arthritis?

- Acute onset of painful, warm, red, swollen joint, especially at night or morning.
- MTP of great toe most common (podagra) but also can be insteps, ankles, heels, knees, wrists, fingers, and elbows.
- Resolves after 3-10 days.

8

What is intercritical gout?

asymptomatic intervals between acute attacks of gout

9

What is chronic tophacous gout?

- subcutaneous, synovial, or subchondral bone deposits of MSU crystals
- commonly on digits of hands and feet, olecranon bursa, extensor surface of the forearm, Achilles tendon, or antihelix of the ear

10

Gout typically occurs in _____, age _____.

men; 30+ (peak incidence 50)

11

What other conditions are associated with gout?

EtOH abuse
obesity
insulin resistance
hypertension

12

How is gout definitively diagnosed?

synovial fluid evaluation

13

In gout, the intracellular crystals in the PMNs are _____-shaped and _____ when parallel to the axis.

needle; yellow

14

In gout, the synovial fluid is inflammatory (______-_____ leukocytes/mm3) with predominance of ______.

20,000-100,000; neutrophils

15

Hyperuricemia can result from ______ or _____ of urate.

increased production; decreased renal excretion

16

The majority of pts (90%) with 1a gout are _____ of uric acid.

underexcretors

17

Urinary uric acid excretion occurs thru a 4 compartment model:

1. glomerular filtration
2. pro-secretory filtration
3. secretion back into the tubule
4. post-secretory reabsorption

18

Net tubular reabsorption is about ____ of the filtered uric acid, therefore only ____ of the UA is excreted in the urine.

90%; 10%

19

What is the urate/organic ion exchanger in the proximal tubule?

URAT1

20

Certain drugs/metabolites decrease the renal excretion of uric acid by activating URAT1, including ____.

nicotinate, pyrazinoate, diuretics, and low-dose aspirin

21

Certain drugs/metabolites increase the urinary excretion of UA by inhibiting URAT1, including _____.

probenecid, sulfinpyrazone, a metabolite of losartan, and high-dose aspirin

22

Uric acid is a product of _____ metabolism bc humans lack the enzyme, _____.

purine; uricase

23

In rare cases, overproduction of UA can be due to superactivity of _____ or deficiencies of ______.

PRPP; HGPRT

24

Complete deficiency of HGPRT results in ______.

Lesch-Nyhan syndrome

25

What are the features of Lesch-Nyhan Syndrome?

mental retardation, spasticity, choreoathetosis, and self-mutilation

26

What factors affect urate solubility?

1. temperature (cold)
2. dehydration
3. trauma
4. pH (less soluble at low pH)

27

Uric acid crystals interact with synovial lining cells leading to the activation of ____ and _____.

monocytes; mast cells

28

How is acute gout treated/prevented?

weight loss
reduction of dietary purines
limitation of fructose and EtOH
NSAIDs
colchicine
corticosteroids

29

How is chronic gout treated?

- uricosuric (probenecid)
- xanthine oxidase inhibitor (allopurinol, febuxostat)

30

What does CPDD stand for?

calcium pyrophosphate dihydrate deposition disease