Baseline characteristics of subjects assigned to the two treatment groups
| Rituximab group (n=41) | Placebo group (n=40) | |
| Sex | ||
| Female | 28 (68%) | 24 (60%) |
| Male | 13 (32%) | 16 (40%) |
| Age (years) | 53.0 (45.0–58.0) | 52.5 (43.0–57.0) |
| C-reactive protein concentration (mg/L), normal <5 mg/L | 3.0 (1.5–5.2) | 2.9 (1.0–5.0) |
| Erythrocyte sedimentation rate (mm/hour), range 1–140 | 10.0 (5.0–15.5) | 10.0 (5.0–15.8) |
| Patient Global Assessment of Disease Activity (mm), range 0–100 | 31.0 (13.0–52.0) | 23.5 (8.0–40.5) |
| TJC68 (range 0–68, 68=maximum) | 2.0 (0–29.0) | 0.0 (0–48.0) |
| SJC66 (range 0–66, 66=maximum) | 0.0 | 0.0 |
| IgM-RF positive* | ||
| Low positive level | 15.0 (37%) | 16.0 (40%) |
| High positive level | 25.0 (61%) | 23.0 (58%) |
| ACPA positive† | ||
| Low positive level | 6.0 (15%) | 4.0 (10%) |
| High positive level | 34.0 (83%) | 36.0 (90%) |
| Shared epitope positive‡ | 21/30 (70.0%) | 24/33 (72.7%) |
| Body mass index (kg/m2) | 28.2 (24.4–31.3) | 26.2 (24.4–29.2) |
| Smoking history ever | 32 (84%) | 27 (71%) |
| Current NSAID use | 23 (56%) | 26 (65%) |
Data are n (%), median (IQR). High positive level is defined by >3 times the upper limit of normal; low positive level is defined by ≤3 times the upper limit of normal.
ACPA, anti-citrullinated peptide antibody; IgM-RF, IgM rheumatoid factor; NSAID, non-steroidal anti-inflammatory drug; SJC66, swollen joint count assessing 66 joints; TJC68, tender joint count assessing 68 joints.
*Of two subjects, IgM titres were not determined at baseline; they were elevated in a prebaseline assessment.
†Of one subject, ACPA titres were not determined at baseline; they were elevated in a prebaseline assessment.
‡Of 11 subjects of the rituximab and seven subjects of the placebo group no data on shared epitope are available.