Difference between revisions of "Rheumatoid Arthritis"

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* [[Type IV Hypersensitivity|Type IV hypersensitivity]]: CD4 Th-1 cell mediated.
 
* [[Type IV Hypersensitivity|Type IV hypersensitivity]]: CD4 Th-1 cell mediated.
 
* Macrophages phagocytose self antigens and can present peptides on their MHC Class II molecules. The autoreactive TH-1 cells release IFN-gamma which activates macrophages to release prostaglandins, MMP enzymes and TNF-alpha (pro-inflammatory mediator), see diagram. These cytokines cause inflammation and tissue destruction.
 
* Macrophages phagocytose self antigens and can present peptides on their MHC Class II molecules. The autoreactive TH-1 cells release IFN-gamma which activates macrophages to release prostaglandins, MMP enzymes and TNF-alpha (pro-inflammatory mediator), see diagram. These cytokines cause inflammation and tissue destruction.
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*Occurs in the dog, mainly smaller breeds
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*Uncommon
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*Progressive erosive polyarthritis
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*Mostly involves elbows, stifles, carpal and tarsal joints
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*Grossly:
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**Marked villus hypertrophy of synovial membrane
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**Cartilage erosion
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**[[Musculoskeletal Terminology - Pathology|Pannus and periarticular osteophyte]] formation
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**In severe cases ankylosis
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*Histologically:
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**Hyperplasia of lining cells
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**Proliferative synovitis
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**Synovial membrane has fibrin deposits
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**Lymphoid and plasma cell infiltration
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**Surrounding haemorrhagic areas
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**Macrophages containing [[Pigmentation - Pathology#Haemosiderin|haemosiderin]]
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**Connective tissue may contain foci of necrosis
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**Areas of erosion of peripheral articular cartilage and underlying subchondral bone
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*Pathogenesis:
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**May involve deposition of immune complexes within joints
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**Substances degrading cartilage are released by synovial cells and macrophages involved in pannus formation
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[[Category:Cell Mediated Autoimmune Diseases]][[Category:To Do - Clinical]][[Category:To Do - Blood]]
 
[[Category:Cell Mediated Autoimmune Diseases]][[Category:To Do - Clinical]][[Category:To Do - Blood]]

Latest revision as of 16:19, 3 March 2011

Rheumatoid Arthritis-Brian Catchpole RVC 2008

Pathogenesis:

  • Type IV hypersensitivity: CD4 Th-1 cell mediated.
  • Macrophages phagocytose self antigens and can present peptides on their MHC Class II molecules. The autoreactive TH-1 cells release IFN-gamma which activates macrophages to release prostaglandins, MMP enzymes and TNF-alpha (pro-inflammatory mediator), see diagram. These cytokines cause inflammation and tissue destruction.


  • Occurs in the dog, mainly smaller breeds
  • Uncommon
  • Progressive erosive polyarthritis
  • Mostly involves elbows, stifles, carpal and tarsal joints
  • Grossly:
  • Histologically:
    • Hyperplasia of lining cells
    • Proliferative synovitis
    • Synovial membrane has fibrin deposits
    • Lymphoid and plasma cell infiltration
    • Surrounding haemorrhagic areas
    • Macrophages containing haemosiderin
    • Connective tissue may contain foci of necrosis
    • Areas of erosion of peripheral articular cartilage and underlying subchondral bone
  • Pathogenesis:
    • May involve deposition of immune complexes within joints
    • Substances degrading cartilage are released by synovial cells and macrophages involved in pannus formation