SM 235a - Crystalline Diseases Flashcards
Which drugs are associated with increased risk of gout?
- Thiazides
- Cyclosporie
- Low-dose aminosalicylates
What kind of crystals are these?

Pseudogout
Rhoboid shaped, weakly positively birefringent
(Blue when parallel to the polarizer = positive biregringence)
Describe the synovial fluid in BCP crystal arthritis
Not inflammatory
(<2000 WBCs)
Describe the microscopic appearance of CPPD crystals
Rhomboid shaped
Weakly positively birefringent = Blue when parallel to the polarizer

Which crystaline disease does not have inflammatory characteristics?
BCP arthropathy
What conditions cause overproduction of uric acid?
What are the consequences?
- Alcohol use
- Enzyme abnormality (disease onset will be early)
- Hemolytic disease
- Myeloproliferative disease
-> increased uric acid -> GOUT
Serum ____________ concentration is associated with gout
Serum uric acid concentration is associated with gout
What agents are used for the chronic management of gout?
- Xanthine oxidase inhibitors
- Decrease production of urate
- Allopurinol (*Hypersensitivity rxn risk*)
- Febuxostat
- Uricosuric agents
- Increase excretion of urate
- Probenecid (*Kidney stone risk*)
- Lesinurad
- Pegloticase
- IV Uricase
- Converts uric acid into allantoin
What are the risk factors for developing gout?
- Increased alcohol consumption
- Increased ATP degradation = increased urate synthesis
- Increased lactic acid = urate excretion
- Beer has the highest purine content of the alcohols
- Obesity
- Metabolic syndrome
- Insulin resistance
What are the treatments for acute gout?
- Colchicine
- NSAIDs
- Intra-articular corticosteroids
Do not start new uric acid lowering treatment during an accute attack
Do not stop uric acid lowering treatment if already taking
What are the 3 main crystal types that can be found in synovial fluid?
- Basic calcium phosphate (BCP)
- Calcium pyrophosphate dihydrate (CPPD)
- Monosodium urate (gout)
What medications are used as prophylaxis for acute gout attacks?
NSAIDs, colchicine, steroids
These can also be used to alleviate pain during an acute attack
Long-term management agents are not prophylactic against acute attacks (although lowering uric acid levels on its own should be prophylactic?)
Which inborn errors of metabolism increase one’s susceptibility to gout?
Leschi-Nyhan
PRPP synthetase mutation
What kind of crystals cause gout?
Monosodium urate monohydrate
- Negatively birefringent (yellow when parallel to the polarizer)
- Needle shaped

What medication increases the excretion of urate?
What condition can this help manage?
Uricosuric agents: Probenecid and Lesinurad
Used for chronic management of gout
BCP crystals deposition in soft tissue causes _________.
What are the consequences?
BCP crystals deposition in soft tissue causes acute calcific periarthritis.
-> intense local inflammation
What is the major risk factor for Calcium Pyrophosphate Dihydrate (CPPD) arthropathy?
Aging
Presentation peaks at 65-75 y/o; F>M
- Tends to affect joints affected by osteoarthritis
What foods increase one’s risk of gout?
- Foods rich in purines
- Purine degradations -> uric acid production
- Meat, shellfish, ethanol, soft drinks, high-fuctose corn syrup
Describe the clinical presentation of gout
- Acute monoarthritis
- Usually involves the 1st MTP
- Any joint can be affected
- Pain often begins in the early AM
- Very acute
- Unable to tolerate teh bedsheets touching the affected joint
- First few attacks are usually self-limited
- Resolve after 7-10 days without therapy
- Subsequent attacks may be more freqent, severe, and resistant to therapy
- If hyperuricemia persists, disease may become chronic and polyarticular
This is an image of synovial fluid obtained from a patient with gout and shows negatively birefringent needle shaped crystals. Which way is the polarizer facing?

C
- Needle-shaped crystals will be yellow when parallel to the polarizer
- This means they are positively birefringent
- Monosodium urate monohydrate crystals cause gout
What are the indications for chronic gout therapy?
Begin chronic therapy if any of the following are present
- > 2-3 gout attacks in 1-2 years
- Renal stones
- Tophaceous gout
- Erosions on x-ray
The metabolism of ______ creates uric acid.
This contributes to the pathologenesis of which crystaline disease?
The metabolism of purines creates uric acid.
Buildup of uric acid leads to gout
What medication decreases the production of urate?
What condition can this help manage?
Xanthine oxidase inhibitors
Ex: Allopurinol, febuxostat
Used for chornic management of gout
What medication is the enzyme uricase given intraveneously?
What condition does this medication treat?
Pegloticase
Converts urate into allantoin
Used for the chronic management of gout


