|
| Site | Score | Description |
|
| Joints |
|
| Cartilage | 0 | Normal |
| 1 | Minimal focal or multifocal erosion of the most superficial layer of cells of articular cartilage |
| 2 | Mild focal or multifocal erosion (5–6 cell layers thick) |
| 3 | Moderate focal or multifocal erosion one-fourth or more of thickness of articular cartilage |
| 4 | Marked focal or multifocal erosion extending to subchondral bone |
|
| Subchondral bone | 0 | Normal |
| 1 | Minimal evidence of osteoclast remodeling only |
| 2 | Mild fibrous proliferation within marrow cavity and osteoclast remodeling |
| 3 | Moderate fibrous proliferation throughout marrow cavity and osteoclast remodeling |
| 4 | Marked destruction of bone with osteonecrosis and osteomyelitis |
|
| Exudate in joint spaces | 0 | None |
| 1 | Minimal (rare) granulocytes and mononuclear cells |
| 2 | Mild accumulations of granulocytes, mononuclear cells, fibrin, and necrotic debris |
| 3 | Moderate accumulations of granulocytes, mononuclear cells, fibrin, and necrotic debris |
| 4 | Marked accumulations of granulocytes, mononuclear cells, fibrin, and necrotic debris |
|
| Synovium/fibrous capsule | 0 | Normal |
| 1 | Minimal (rare to occasional) granulocytes and macrophages in synovium/fibrous capsule |
| 2 | Mild accumulations of scattered granulocytes and macrophages in synovium/fibrous capsule |
| 3 | Moderate, dense accumulations of granulocytes, and macrophages limited to fibrous capsule ± edema |
| 4 | Marked destruction of fibrous capsule with infiltration into adjacent soft tissues |
|
| Brain |
|
| Meningitis | 0 | No lesions |
| 1 | Mild focal meningitis |
| 2 | Moderate focal or mild to moderate multifocal meningitis |
| 3 | Focal granulomas associated with meninges |
| 4 | Severe focal or moderate to severe multifocal meningitis |
|
| Encephalitis | 0 | No lesions |
| 1 | Mild focal encephalitis with infiltration of scattered heterophils and macrophages in neuropil. Minimal tissue destruction |
| 2 | Moderately dense infiltrates of heterophils and macrophages with associated tissue destruction |
| 3 | Severe focal or multifocal encephalitis with dense infiltrates of heterophils and macrophages and associated severe destruction of tissue |
|
