Other Autoimmune Diseases 2 Flashcards
Describe the pathophysiology of Amyloidosis.
Body is unhappy due to misfolded proteins that aggregate and form insoluble fibers known as amyloid. Amyloid develops due to:
1) Too much protein production
2) Mutated proteins that misfold/can’t be broken down
3) incomplete protein breakdown
How do you diagnose amyloidosis?
Rectal tissue biopsy (easy access)
What do you see on histology for amyloidosis (SUPER HIGH YIELD)
B-pleated sheets that show apple green birefringence under polarized light.
Stain: congo red
NEVER FORGET
What is a commonly affected organ in amyloidosis and how does this organ look after it gets all amyloided up
Heart
Myocardial hypertrophy leads to ECG changes, arrhythmias, and a waxy looking endocardium.
What is localized amyloidosis and what is an example?
Amyloid goes to a single organ to produce a mass (or only be seen on microscopic exam)
Example:
1) Endocrine (medullary carcinoma of the thyroid a/w microscopic amyloid)
2) Alzheimer (brain)
There are 3 types of systemic amyloidosis. Name them
1) Primary
2) Secondary
3) Hemodialysis associated
What is primary amyloidosis all about? What is the major fibril found here?
Clonal proliferation of plasma cells that make Ig that is prone to misfold and form amyloid
Major fibril: AL (amyloid light chain)
What might you see on labs and histology for primary amyloidosis
Serum Electrophoresis: M spike (monoclonal Ig production)
Histo: Bence Jones proteins, Rouleaux formation
What conditions are associated with primary amyloidosis?
1) Multiple Myeloma
2) B-cell neoplasm
3) Waldenström macroglobulinemia
Describe the pathophysiology of secondary amyloidosis?
1) Chronic inflammation
2) Activated macrophages secrete IL-1/IL-6 which stimulates liver to make SAA protein
3) Lots of SAA because of lots of inflammation
4) Add in a defect in protein break own and you get SAA accumulation and amyloid deposition
What is the major fibril you see in secondary amyloidosis?
Major fibril: AA (amyloid-associated)
What disease is commonly associated with secondary amyloidosis?
RA
What is Hemodialysis associated amyloidosis and what fibril is it associated with
Major fibril: AB2-microglobulin deposition
Path: this protein can’t be filtered through dialysis membranes in renal failure pts on long-term hemodialysis *New dialysis filters make this less common.
What is Familial Mediterranean Fever. What is the major fibril seen?
Excessive IL-1 production in response to inflammatory stimulus. Gene implicated in FMF codes for pyrin protein which is a/w proinflammatory response regulation
Major fibril: AA
Who is commonly affected by Familial Mediterranean Fever
Armenians, Sephardic Jews and Arabs
Systemic senile amyloidosis (aging). What’s this all about? What’s the major fibril seen?
People get old, and get lots of protein shit buildup. Most commonly involves the heart w/ cardiomyopathy and arrhythmias
Major fibril: ATTR (transthyretin amyloidosis)
SARCOIDOSIS. Other than having an AA female, how else will you know your patient has this?
Diagnosis of exclusion but also look for:
1) Noncaseating granulomas and enlarged hilar lymph nodes
2) Dyspnea, cough, chest discomfort
3) Lung Crackles
4) Skin lesions
5) Joint pain
6) Anorexia, weight loss
7) Arrhythmias (5%)
What lab findings will you see with sarcoidosis?
1) Increased Ca/vit D(active 1-A hydroxylase)
2) Increased ACE
3) Abnormal liver enzymes
4) Hypercalcemia
5) Hypercalciuria
What high yield stuff do you see on histology for sarcoidosis?
1) Fibrosis
2) Epithelioid histiocytes (multinucleated giant cell)
3) Star-shaped asteroid bodies
4) Schaumann bodies (laminated calcification)
What triad of sx do you see in Loefgren’s Syndrome (acute sarcoidosis) and what other sx might also come up?
Triad:
1) acute polyarthritis
2) erythema nodosum
3) hilar adenopathy
Other sx: malaise, fever, joint disease, uveitis, parotitis
This disease is self limited with rare relapse. Take some NSAIDs for it and you’ll be just fine.
Hypersensitivity Pneumonitis. What’s the idea here?
You inhale something, get granuloma formation and have sx of fever, cough, dyspnea. Chronic inhalation can lead to interstitial fibrosis.
You stop inhaling it, and sx go away. MAGIC.
What are some fun examples of hypersensitivity pneumonitis?
1) Farmer’s lung (dusts from humid hay = rapid proliferation of the spores of thermophilic actinomycetes),
2) Pigeon breeder’s lung (from bird proteins),
3) Humidifier/AC lung (from thermophilic bacteria in heating reservoirs)
What the pathology associated with Osteoarthritis?
Progressive degeneration of ARTICULAR CARTILAGE (not the synovium like RA!) in joints due to wear and tear
What are the many sx associated with osteoarthritis
1) Joint pain
2) Limb buckling/instability
3) Limited ROM
4) Crepitus
5) Joint deformity
6) Morning stiffness that WORSENS THROUGH DAY (unlike RA)
What lab abnormalities will you see with osteoarthritis?
NONE
ha tricked ya didn’t I. Nah, probs not cuz you so smaht
Describe the joints typically involved in oastoarthrits?
1) Hips
2) Knees
3) MTP
4) Cervical/lumbar spine
5) CMC squaring
6) DIP (Heberden nodes) and PIP (Bouchard nodes)
Joint mice are ________.
Bone fragments floating in joint space. Seen in osteoarthritis
RA is a type of inflammatory arthritis. Another kind of inflammatory arthritis that is associated with a skin rash is _____________
Psoriatic Arthritis.
What other sx are associated with Psoriatic Arthritis.
- SAUSAGE fingers and toes (dactylitis)
- Axial joint involvement
- Nail pits
- Arthritis mutilans (shortening of fingers by arthritis, sometimes so severe that hands look like paws)
What X-ray findings are associated with psoriatic arthritis?
- *Pencil-in-cup deformities
- Soft tissue swelling
- Lack of osteopenia
- Decreased bone mineralization
What 3 things classify the seronegative spondylarthropathies?
- Negative rheumatoid factor
- Axial skeleton involvement
- HLA-B27 association
The 2 seronegative spondylarthropathies we will talk about are __________ and ____________.
- Ankylosing Spondylitis
2. Reactive Arthritis
Ankylosing Spondylitis first. 1) What are the sx, 2) who is typically affected, and 3) what key finding will you see on X-ray.
- low back pain, uveitis
- Affects males, typically young adults
- X-ray finding: bamboo spine: fusion of vertebrae
Now for reactive arthritis. What kinds of infections lead to this disorder and what symptoms will you see?
- Infections include GU (Chlamydia) or GI (shigella, samonella, yersinia, campy)
- Sx are constitutional, asymmetric polyarthritis in knee/large joints
In infectious arthritis, what kind of organism is typically causing the infection? How does it get to the joint??
Bacteria usually spread hematogenously from nearby infected tissue.
*Gotta be super careful of this kind of infection in ARTIFICIAL JOINTS.
Acute infectious arthritis is typically bacterial or viral. In bacterial, what joints are involved and what symptoms will you see?
Usually SINGLE joint, (usually knee, rarely axial)
Symptoms will include severe, acute pain, warm joint, limited ROM and fever
What are the common criminals of infectious bacterial arthritis? How do you get rid of em?
N. gonorrhea, S. aureus (spreads from infected mucosa).
Tx includes IV antibiotics
Who are the common culprits of viral infectious arthritis?
- Rubella
- Parvo B19
- HepA/B/C
- HIV
- HTLV1
- Chikungunya
When you treat Lyme disease, does it typically recur?
Yes.
Tuberculosis can give you some arthritis too. This develops over weeks. What is the name of TB in the joints
Pott disease. Affects the spine predominantly.
What fungus gives you arthritis?
CANDIDADADADADADA
Describe the pathophysiology involved in gout.
- Purine metabolism produces uric acid. Excess production or decreased excretion of uric acid –> hyperuricemia.
- Monosodium urate crystals (MUC) deposit in tissues/joints
- Crystals trigger acute inflammatory response. Mostly neutrophils.
What symptoms will you see in gout?
- Sudden onset painful arthritis
- Red, warm joint
- First attack to great toe (Podagra)
- Mild fever
What lab findings and synovial fluid findings will you see in gout?
- Labs: hyperuricemia, plasma urate >6.8
2. Synovial fluid: yellow needle-shaped crystals with negative birefringence under polarized light
What are the risk factors for gout? So mannyyyyyy
- Old age
- Male
- Family history of the condition
- Obesity
- drugs (diuretics, low-dose aspirin, cyclosporine, or levodopa)
- Binge drinking 7. Lead toxicity
- Organ transplants
- Thyroid problems
What might trigger a gout attack?
- Dehydration
- Joint injury
- Overindulging in alcohol or purine-rich foods
- Severe illness or infection
- Sudden weight loss/ “crash diets”
- Surgery
What’s the difference between primary and secondary gout?
Primary: unknown cause of hyperuricemia
Secondary: caused by underlying condition like LEUKEMIA, LESCH-NYHAN syndrome or RENAL INFUFFICIENCY
What is tophaceous gout?
repeated attacks of acute gout leads to chronic inflammation and cartilage damage. You will see tophi formation, which is white, chalky aggregates of uric acid crystals. If the crystal deposit in the kidney tubules this can lead to kidney failure
What do you see on X-ray for tophaceous gout?
juxta-articular bone erosion by osteoclasts
What’s the difference between gout and pseudo gout?
Same clinical presentation but:
- Deposition of calcium pyrophosphate dehydrate (CPPD) crystals (not MSU)
- Blue rhomboid shaped crystals that have positive birefringence under polarized light
Juvenile Idiopathic Arthritis shows was joint distribution and affects what demographic?
- Asymmetric, LE spondyloarthropathy
2. boys 7-16 years old
