Gout and Crystalline Arthropathies

Question 1

What is the key pathologic difference between gout and pseudogout?

Answer 1

Gout is the overproduction or underexcretion of uric acid. Pseudogout (CPPD) is the deposition of calcium pyrophosphate

Question 2

Where is gout most common? Where is CPPD most common?

Answer 2

Gout commonly deposits in 1st MTP and forefoot/ankle. CPPD more common in knees and wrists

Question 3

What is the difference in crystals between CPPD and gout?

Answer 3

Gout has intracellular and extracellular negative birefringent needle shaped crystals. CPPD crystals are rhomboid shaped, and positively birefringent.

Question 4

What does hyperuricemia result in?

Answer 4

Gout; via deposition of tophi in joints, kidney and skin.

Question 5

What is uric acid derived from?

Answer 5

Breakdown of purine nucleotides.

Question 6

What is a critical enzyme in the production of uric acid? What are two drugs that block this enzyme?

Answer 6

Xanthine oxidase converts hypoxanthine to xanthine and then to uric acid

Question 7

What do most patients with gout have it as a result of? What drugs aid in this issue to treat gout?

Answer 7

The buildup of uric acid crystals is due to the fact they are under excretors. Probenecid and benzbromarone block reuptake of uric acid in kidney

Question 8

Why does deposition of urate crystals in joints cause gout?

Answer 8

They are phagocytosed in the joints and lead to inflammation and overproduction of IL-1. NALP3 in the inflammasome is activated.

Question 9

What is an IL-1 receptor antagonist that can be used in treatment of gout?

Answer 9

Anakinra (Kineret)

Question 10

What are 4 key drugs used in acute treatment of gout?

Answer 10

NSAIDs, glucocorticoids, colchicine, and anakinra (IL-1 receptor antagonist)