SM_235a: Crystalline Diseases

Question 1

All crystalline arthropathies are characterized by _____ and _____

Answer 1

All crystalline arthropathies are characterized by inflammation in the joint and crystals in synovial fluid

Question 2

Describe inflammatory synovial fluid analysis

Answer 2

Inflammatory synovial fluid analysis

• Slightly turbid appearance
• 2,000-50,000 WBCs/mm^3
• 20-70% PMNs

Question 3

____, ____, and ____ are the main crystal types

Answer 3

Basic calcium phosphate (BCP), calcium pryophosphate dihydrate (CPPD), and monosodium urate (gout) are the main crystal types

Question 4

Basic calcium phosphate crystal are also known as _____

Answer 4

Basic calcium phosphate crystal are also known as calcium hydroxyapatite

Question 5

Basic calcium phosphate (BCP) crystals deposit in _____, _____, and _____

Answer 5

Basic calcium phosphate crystals (BCP) deposit in soft tissue (acute calcific periarthritis), joints (BCP arthropathy), and tendons (calcific tendinitis)

• Soft tissue (acute calcific periarthritis): 1st MTP in young women (pseudo-podagra)
• Joints (BCP arthropathy): Milwaukee shoulder syndrome
• Tendons (calcific tendinitis): shoulder, most commonly in supraspinatus tendon

Question 6

Acute calcific periarthritis occurs when BCP crystals are shed from ____ and deposit in ____

Answer 6

Acute calcific periarthritis occurs when BCP crystals are shed from calcific deposit and deposit in soft tissues

• BCP crystals shed from calcific deposit of BCP arthropathy or calcific tendinitis
• Intense local inflammation

Question 7

BCP causes acute calcific periarthritis of ____ in young women (pseudo-podagra)

Answer 7

BCP causes acute calcific periarthritis of 1st MTP in young women (pseudo-podagra)

Question 8

BCP deposit in ____ causes ____, which is severe degenerative arthritis of the shoulder joint

Answer 8

BCP deposit in joints causes Milwaukee Shoulder Syndrome, which is severe degenerative arthritis of the shoulder joint

• Loss of rotator cuff, cannot abduct arm, huge swelling
• BCP crystals identified
• Woman > 70s
• Bilateral involvement common
• Can affect other joints such as finger (Philadelphia finger)

Question 9

BCP deposit in joints of the finger causes _____

Answer 9

BCP deposit in joints of the finger causes Philadelphia finger

Question 10

BCP deposits in tendons causes _____, most commonly in tendons of the _____

Answer 10

BCP deposits in tendons causes calcific tendinitis, most commonly in tendons of the shoulder

• Usually in muscles that abduct and stabilize the shoulder
• Bursitis, impingement syndrome
• Can also involve hand, wrist, hip, knee, foot, neck

Question 11

BCP appearance on microscopy includes _____, _____, and _____

Answer 11

BCP appearance on microscopy includes shiny coins on ordinary light microscopy, NOT birefringent on polarized light microscopy, and joint aspirate stained for alizarin red

Question 12

BCP is _____ on polarized light microscopy

Answer 12

BCP is NOT birefringent on polarized light microscopy

Question 13

EM of BCP crystals shows _____ in synovial fluid demonstrating _____

Answer 13

EM of BCP crystals shows rice bodies in synovial fluid demonstrating apatite crystals

Question 14

Synovial fluid in BCP crystals is _____

Answer 14

Synovial fluid in BCP crystals is non-inflammatory

(like OA)

Question 15

BCP arthropathy is treated if the patient is _____ and includes _____, _____, _____, and _____

Answer 15

BCP arthropathy is treated if the patient is asymptomatic and includes NSAIDs, PT, intra-articular steroids, and surgery if indicated

Question 16

Describe the ABCs of BCP arthropathy

Answer 16

ABCs of BCP arthropathy

• A: acute calcific periarthritis, alizarin red stain, atypical gout (young woman)
• B: BCP arthropathy, NOT birefringent
• C: calcific tendinitis, cuff (supraspinatus), coins shiny on light microscopy

Question 17

Describe calcium pyrophosphate dihydrate (CPPD) arthropathy

Answer 17

CPPD arthropathy (formerly known as pseudogout)

• Calcium pyrophosphate deposition in joints
• Major risk factor is aging: peaks 65-75 years
• Female to male is 2-7:1
• Predilecton for joints affected by osteoarthritis
• Associated with numerous metabolic disturbances: screen if onset of disease < 55 years

Question 18

Check ____, ____, and ____ levels is suspecting CPPD

Answer 18

Check Mg, iron/ferritin, and TSH levels is suspecting CPPD

Question 19

Describe the clinical presentations of CPPD

Answer 19

CPPD clinical presentations

• Pseudogout (gout mimic): acute monoarthritis (knees > wrist > shoulder > ankle and elbow)
• Chronic polyarthritis (RA mimic): symmetric, small joints
• Progressive osteoarthritis: involves large and small joints, crowned dens syndrome (spinal involvement)
• Asymptomatic chondrocalcinosis

Question 20

CPPD mimics ____ by causing ____

Answer 20

CPPD mimics gout by causing acute monoarthritis

(knees > wrist > shoulder > ankle and elbow)

Question 21

CPPD mimics ____ by causing ____

Answer 21

CPPD mimics RA by causing chronic polyarthritis

(symmetric, small joints)

Question 22

CPPD with spinal involvement causes _____

Answer 22

CPPD with spinal involvement causes crowned dens syndrome

Question 23

Describe radiographic manifestation of CPPD

Answer 23

CPPD radiographic manifestations

• Can have chondrocalcinosis without pseudogout and vice versa
• Meniscus and triangular fibrocartilage of wrist often show classic findings

Question 24

CPPD crystals are ____ and ____ on polarized light microscopy

Answer 24

CPPD crystals are pleomorphic and weakly positive birefringent on polarized light microscopy

(look rhomboidal, weak tint)

Question 25

Describe CPPD treatment

Answer 25

CPPD treatment * NSAIDs * Intra-articular or oral steroids * Colchicine: use caution given elderly population * Anakinra: not FDA approved * Weak data on hydroxychloroquine and methotrexate * No true prophylaxis and treat acute gout attach

Question 26

\_\_\_\_ and ____ cause non-gout arthropathies

Answer 26

BCP and CPPD crystals cause non-gout arthropathies * BCP: soft tissue (acute calcific periarthritis) - 1st MTP in young women (pseudo-podagra), joints (BCP arthropathy) - Milwaukee Shoulder Syndrome, tendons (calcific tendinits) - shoulder most commonly supraspinatus tendon * CPPD: spectrum of presentations, Crowned Dens syndrome, primary (pseudogout, RA, OA, Charcot, asymptomatic, etc), secondary (check PTH, Ca, P, Mg, TSH levels)

Question 27

Describe gout

Answer 27

Gout * Increased prevalence with increased age and increased uric acid * [uric acid] rises decades before development of goat * Males: onset of puberty -\> disease onset \> 30 yo * Females: perimenopausal phase -\> disease onset 60 yo (estrogen is uricosuric) * Male predominant disease until menopause after which rates equalize * 50% have gout if UA \> 10 mg/dl * Positive FMHx in 50%

Question 28

Describe risk factors for gout

Answer 28

Gout risk factors * Alcohol consumption especially beer * Obesity, metabolic syndrome, insulin resistance * Diet rich in purines: meat, shellfish, ethanol, soft drinks, high fructose syrup * Drugs: thiazide, cyclosporine, low dose ASA (\<1 g / day) * Renal insufficiency * Organ transplantation * Inborn errors of metabolism: Lesch-Nyhan, PRPP synthetase

Question 29

Amount of alcohol consumed directly correlates with goat risk because _____ while \_\_\_\_\_

Answer 29

Amount of alcohol consumed directly correlates with goat risk because increased ATP degradation leads to increase urate synthesis while increased lactic acid leads to decreased urate excretion (beer has highest purine content)

Question 30

Hyperuricemia is primarily caused by \_\_\_\_\_

Answer 30

Hyperuricemia is primarily caused by underexcretion (decreased renal function, drugs, alcohol use)

Question 31

Describe the stages of gout

Answer 31

Gout 1. Asymptomatic hyperuricemia: 15% will develop gout after 20 years of hyperuricemia 2. Acute gouty arthritis: 85-90% in a single joint 3. Intercritical gout (quiescent intervals between gout attachs): 60% have another attack within 24 months, 5-10% never have another attack 4. Chronic tophaceous gout: after 10 years of uncontrolled disease

Question 32

Describe the acute clinical presentation of gout

Answer 32

Gout acute clinical presentation * Acute monoarthritis: usually involving 1st MTP (podagra) * Pain often begins very early in morning: very acute * First few attacks are often self-limited * Subsequent attacks may be more frequent, severe, and resistant to therapy * If hyperuricemia persists, the disease can become chronic and polyarticular

Question 33

Chronic tophaceous gout involves deposits in the ____ and _____ in addition to the toe

Answer 33

Chronic tophaceous gout involves deposits in the pinna and elbow in addition to the toe

Question 34

Gout is _____ shaped and _____ when parallel to a polarizer

Answer 34

Gout is needle shaped and yellow when parallel to a polarizer (blue when perpendicular to polarizer, treat with allopurinol)

Question 35

Describe radiographic manifestations of gout

Answer 35

Gout radiographic manifestations * Large erosions * Punched-out lesions * Soft tissue tophi * Sclerotic overhanging edges * Preserved joint spaces

Question 36

Therapeutic goals for gout are \_\_\_\_, \_\_\_\_, and \_\_\_\_

Answer 36

Therapeutic goals for gout are providing rapid and safe pain relief, preventing further attacks, and preventing formation of tophic and destructive arthritis

Question 37

First line therapy for gout includes \_\_\_\_, \_\_\_\_, and \_\_\_\_

Answer 37

First line therapy for gout includes NSAIDs, colchicine, and corticosteroids

Question 38

Indications for chronic therapy for gout are \_\_\_\_, \_\_\_\_, \_\_\_\_, and \_\_\_\_

Answer 38

Indications for chronic therapy for gout are \> 2-3 gout attacks for 1-2 years, renal stones, tophaceous gout, and erosions on X-ray

Question 39

Describe chronic management of gout

Answer 39

Gout chronic management * Xanthine oxidase inhibitors (decrease production of urate): allopurinol (risk for hypersensitivity reactions), febuxostat * Uricosuric agents (increase excretion of urate): probenecid (risk for kidney stones), lesinurad * Pegloticase: uricase IV, very potent urate lowering agent, immediate hypersensitivity reactions common * Anakinra (anti-IL1 biologic therapy)

Question 40

Primary chronic management of gout is \_\_\_\_\_

Answer 40

Primary chronic management of gout is xanthine oxidase inhibitors (allopurinol, febuxostat) (allopurinol has risk of hypersensitivity reactions)

Question 41

Summarize BCP, CCPD, and gout crystals

Answer 41

BCP, CCPD, and gout crystals