Table 1.
Characteristics of patients under study
| Osteoarthritis | Rheumatoid arthritis | |
| n | 26 | 25 |
| Age, years | 71 ± 2 [55–88] | 66 ± 2 [39–84] |
| Gender, F/M | 21/5 (81/19) | 19/6 (76/24) |
| Disease duration, years§ | 5 ± 1 | 10 ± 1 |
| Erythrocyte sedimentation rate, mm/1st hr | 16.6 ± 3.2 | 35.2 ± 7.2** |
| C-reactive protein, mg/l | 6.6 ± 0.9 | 26.3 ± 7.5# |
| Rheumatoid factor positive | 1/26 (0.5) | 12/25 (48.0) |
| Lining layer, cells | 2.1 ± 0.1 | 3.9 ± 0.3## |
| Cell density, cells/mm2 | 1257 ± 121 | 1864 ± 202** |
| T cell density, cells/mm2 | 22.2 ± 4.7 | 58.8 ± 20.1 |
| CD163+ macrophage density, cells/mm2 | 54.7 ± 10.1 | 101.3 ± 20.5* |
| Vascularity, vessels/mm2 | 28.8 ± 2.9 | 31.1 ± 3.7 |
| Medication | ||
| Prednisolone | n.a. | 19 (76.0) |
| Mean prednisolone dose, mg/d | n.a. | 5.2 ± 0.9 |
| NSAIDs | 14/26 (54.0) | 20/25 (80.0) |
| Methotrexate | n.a. | 4/25 (16.0) |
| Leflunomide | n.a. | 8/25 (32.0) |
| Azathioprine | n.a. | 1/25 (4.0) |
| Sulfasalazine | n.a. | 1/25 (4.0) |
| Hydroxychloroquine | n.a. | 4/25 (16.0) |
| Cyclosporin A | n.a. | 1/25 (4.0) |
| Anti-TNF therapy strategies | n.a. | 0/25 (0.0) |
*p = 0.065, **p < 0.05, #p < 0.01, ##p < 0.001 for the comparison versus osteoarthritic patients. §Disease duration in OA patients is a rough estimate because the exact starting point is often not precisely known. Data are given as means ± SEM, percentages in parentheses, and ranges in square brackets. F/M, female/male; n.a., not applicable; NSAIDs, non-steroidal anti-inflammatory drugs; TNF, tumor necrosis factor.