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Line 4: |
| | * [[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 |
| | + | *Uncommon |
| | + | *Progressive erosive polyarthritis |
| | + | *Mostly involves elbows, stifles, carpal and tarsal joints |
| | + | *Grossly: |
| | + | **Marked villus hypertrophy of synovial membrane |
| | + | **Cartilage erosion |
| | + | **[[Musculoskeletal Terminology - Pathology|Pannus and periarticular osteophyte]] formation |
| | + | **In severe cases ankylosis |
| | + | *Histologically: |
| | + | **Hyperplasia of lining cells |
| | + | **Proliferative synovitis |
| | + | **Synovial membrane has fibrin deposits |
| | + | **Lymphoid and plasma cell infiltration |
| | + | **Surrounding haemorrhagic areas |
| | + | **Macrophages containing [[Pigmentation - Pathology#Haemosiderin|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 |
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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]] |