Table 1 Baseline characteristics of the study subjects per group
|  | HCQ withdrawal (N = 26) | HCQ continuation (N = 32) | p value |
|---|---|---|---|
Age (HCQ discontinued or matched) | 60.4 ± 4.1 | 59.8 ± 4.3 | 0.53 |
Female gender | 25 (96.2%) | 31 (96.9%) | 1.00 |
Race/ethnicity | Â | Â | 0.94 |
 White | 7 (26.9%) | 11 (34.4%) |  |
 Black | 8 (30.8%) | 9 (28.1%) |  |
 Asian | 6 (23.1%) | 6 (18.8%) |  |
 Hispanic | 5 (19.2%) | 6 (18.8%) |  |
Duration of SLE, years* | 24.3 ± 10.6 (n = 25) | 17.8 ± 11.8 (n = 28) | 0.03 |
Duration of HCQ use, years** | 13.0 (8–23, n = 23) | 14.0 (6–22, n = 27) | 0.70 |
Number of ACR criteria met* | 4.6 ± 0.9 | 5.4 ± 1.5 | 0.04 |
 History of arthritis | 20 (76.9%) | 23 (71.9%) | 0.89 |
 History of lupus nephritis | 11 (42.3%) | 14 (43.8%) | 1.00 |
 History of serositis | 8 (30.8%) | 10 (31.3%) | 1.00 |
Complement, C3 | 108.1 ± 16.4 (n = 20) | 100.5 ± 27.6 | 0.12 |
Complement, C4 | 26.0 ± 10.6 (n = 21) | 21.3 ± 10.3 | 0.09 |
Low C3 or C4* | 3/25 (12.0%) | 14/32 (43.8%) | 0.02 |
Presence of anti-dsDNA Ab | 7 (28.0%, n = 25) | 9 (29.0%, n = 31) | 1.00 |
Immunosuppressive use | 4 (15.4%) | 8 (25.0%) | 0.52 |
 AZA only | 0 | 2 (6.3%) |  |
 MMF only | 0 | 3 (9.4%) |  |
 MTX only | 1 (3.8%) | 1 (3.1%) |  |
 Others only†| 2 (7.7%) | 1 (3.1%) |  |
 Combination‡ | 1 (3.8%) | 1 (3.1%) |  |
Prednisone use | 2 (7.7%) | 5 (15.6%) | 0.44 |
Statin use | 5 (19.2%) | 3 (9.4%) | 0.45 |
Clinical SELENA-SLEDAI score | 0.2 ± 0.8 | 0.2 ± 0.8 | 0.70 |
SELENA-SLEDAI score | 0.9 ± 1.4 | 1.8 ± 1.8 | 0.08 |