LOCO6 Flashcards
Explain the pathophysiology of heterotopic bone [3]
Fibroblasts, osteoblasts and chondroblasts come from same precursors
Tendon fibroblast differentiate into chondrocytes / hypertrophic chondrocyte and osteoblasts via COX-2
Pro-inflammtory cytokines like prostaglandin E2 induces osteoblasts to differentiate
Define sharpey fibres [1]
Sharpey’s fibres: are a matrix of connective tissue consisting of bundles of strong predominantly type I collagen fibres connecting periosteum to bone.
Label A
sharpey fibres
Describe enthesitis pathogenesis:
Normal enthesitis insertion occurs at a location with lots of which structure? [1]
How does this influence enthesitis pathogenesis? [3]
Normal enthesis inserts into porous bone at a location with lots of small transcortical vessels (TCV)
Mechanical trauma; TCVs become inflammed:
* Vasodilation
* Efflux of immune cells (neutrophils)
* Osteoblasts form bone at enthesis - causes bone to be formed
Enthesitis is associated with which three conditions? [3]
Ankylosing spondylitis
Psoriatic arthritis
IBD
How do you treat enthesitis:
- If mechanical? [2]
- If Inflammatory [5]
Mechanical:
* RICE
* NDSAIDs
Inflammatory:
* Sulfasalazine
* Methotrexate
* Anti-TNF therapy (restricted use for severe autoimmune enthetitis)
* Local radiotherapy
* Corticosteroid injection
* Hyperosmolar dextrose (initiates proliferation of intrinsic fibroblasts - race to repair damage c.f. osteoblasts)
Which drug class is used for ankylosing spondylitis enthesitis? [1]
Anti-TNF treatment
What are the names for arteries that supply tendons (of the hands)? [1]
Vincular arteries
Explain pathophysiology of De Quervien tenosynovitis [3]
Fibrosis and narrowing of tendon sheath: extensor retinaculum
Around anatomical snuffbox
Causes tendons and sheath rubbing over radial styloid process
Thickening and narrowing of tendon sheath
Lymphocyte inflammation
State and describe the name for test of De Querviens tensynovitis [1]
Finkelstein test:
- Patient resting their forearm on a surface in a neutral position with the wrist hanging off and unsupported
- The examiner holds the patient’s thumb and passively flexes the thumb into the palm, causing the wrist to adduct (ulnar deviation), putting **strain on the APL and EPB tendons. **
- If this causes pain at the radial aspect of the wrist, the test is positive, indicating De Quervain’s tenosynovitis.
Treatment for tenosynovitis?
Treatments [4]
Surgery - for trigger finger [1] and De Quervains [1]
Treatment:
* RICE
* Splinting
* Anti-inflam
* Corticosteroids
Surgery:
* TF: cut annular ligament
* DQ: shave styloid processs or cut sheath
DMARD treatments for SLE? [4]
Cylcophosphamide
Mycophenolate mofetil
Methotrexate
Tacrolimus
Describe two biological DMARDs for SLE? [2]
Belimubab: inhibits BAFF (B cell activating factor)
Rituximab: CD20 blocker
Describe the role of Langerhan cells [3]
Dendritic cell - spine-like projections
Efficient at presenting antigen to CD4+ helper T-cell
Pick up antigens that enter the skin and transport them to the lymph node
Staining dendritic cells n epidermis in a patient with skin infection.
Name an allergen produced by dust mice [3]
How does it cause damage to airway epithelium? [1]
Der P1 is an enzyme allergen
from the faecal pellets
of the dust mite.
Der P1 breaks down components of tight junctions which helps it to cross mucosa.
Binds to mast cells and causes degranulation
How can you treat resistant urticaria and asthma?
Omalizumab: binds free IgE in the serum, forming trimers and hexamers
What is Pemphigus Vulgaris? [2]
autoimmune disease caused by antibodies directed against desmoglein 3, a cadherin-type epithelial cell adhesion molecule
Antibody and complement binds to desmoglein 3: causes acantholysis (loss of coherence between epidermal cells due to the breakdown of intercellular bridges)
Treatment of Pemphigus Vulgaris? [3]
Oral steroids
Immunosuppresion: mycophenolate mofetil or azathioprine
Rituximab (targeting CD20 on B cells)
Describe the features of Immune Complex Mediated Vasculitis [4]
Antigen and antibody form an immune complex
This causes production of proteins and aggregation of platelets into micro thrombi
This results in:
* Deposition of fibrin
* Leaky vessel and extravasation of blood and oedema.
* The proteases degrade vessel BMZ
* Necrosis of the vessel wall
Allergic Contact Dermatitis pathogenesis? [3]
Promotion of Th1 response:
- Secretion of IL2, IL3, GM-CSF, IFNg and TNF
- This promotes a macrophage rich response
- Causes inflammation to the skin around 48 hours to 72 hours after the challenge
Describe formation of granulomas
Clonal T-cell expansion
Secretion of
Th1 cytokines:
IL-2, IFN-g, TNF causes the creation of macrophages
New drug class treatments for AA and Vitiligo? [1]
Name an example drug [1]
JAK Inhibitors
E.g Ruxolitinib
Two potential AEs of JAK inhibitors? [2]
Thromboembolic events
Cancer related events
Pemphigus Vulgaris occurs due to autoantibodies directed at a cadherin-type epithelial cell adhesion molecule called what? [1]§
Desmoglein 3
Oral steroids; mycophenolate mofetil or azathioprine and / or Rituximab would be used to treat which skin condition? [1]
Pemphis vulgaris
Allergic contact dermatitis is caused by which type of response
Th1
Th2
Th17
Th5
Allergic contact dermatitis is caused by which type of response
Th1
Granuloma formation is a which type of hypersensitivity reaction?
Type 1
Type 2
Type 3
Type 4
Type 4
This person with a tattoo has an adverse reaction. This occurs due to
Mast cell-mediated inflammation
Antibody-mediated inflammation
Immune complex mediated inflammation
Delayed hypersensitivity
Automimmunity
Immune complex mediated inflammation
Ruxolitinib is a JAK inhibitor used to treat [2]
Vitiligo
Phemphis vulgaris
Leukocytoclastic vulgaris
Urticaria
Ruxolitinib is a JAK inhibitor used to treat
Vitiligo
Phemphis vulgaris
Leukocytoclastic vulgaris
Urticaria
Granuloma formation is caused by which type of response
Th1
Th2
Th17
Th5
Th1
