Patient characteristics
| SLE (n=50) | RA (n=139) | p Value | |
|---|---|---|---|
| Age, years | 36±13 | 59±8 | <0.0001 |
| Female, n (%) | 46 (92%) | 85 (61%) | <0.0001 |
| Race/ethnicity | |||
| White, n (%) | 2 (4%) | 121 (87%) | <0.0001 |
| Hispanic, n (%) | 37 (74%) | 1 (1%) | <0.0001 |
| Black, n (%) | 11 (22%) | 1 (1%) | <0.0001 |
| Disease duration, years | 6 (2–10) | 8 (4–16) | 0.0005 |
| SLEDAI-2K | 6 (2–12) | – | – |
| Lupus nephritis, n (%) | 22 (44%) | – | – |
| APS, n (%) | 3 (6%) | – | – |
| Moderate–severe disease activity*, n (%) | 21 (42%) | 86 (62%) | 0.02 |
| DAS28 | – | 3.6±1 | – |
| CRP, mg/L | 4.7(1.0–31.5)† | 2.1 (1–5.9) | 0.03 |
| IL-6, pg/mL | – | 3.6 (1.6–7.7) | – |
| Antimalarials, n (%) | 32 (64%) | 23 (17%) | <0.0001 |
| Mycophenolate mofetil, n (%) | 21 (42%) | – | – |
| Azathioprine, n (%) | 5 (10%) | – | – |
| Non-biologic DMARD, n (%) | – | 117 (84%) | – |
| Biologic DMARD, n (%) | – | 66 (48%) | – |
| Current glucocorticoid use, n (%) | 27 (54%) | 50 (36%) | 0.03 |
| ds-DNA antibody, n (%) | 41 (82%) | – | – |
| SSA antibody, n (%) | 28 (56%) | – | – |
| SSB antibody, n (%) | 16 (32%) | – | – |
| Sm antibody, n (%) | 24 (48%) | – | – |
| RNP antibody, n (%) | 29 (58%) | – | – |
| RF>40 units, n (%) | – | 85 (61%) | – |
| Anti-CCP>60 units, n (%) | – | 94 (68%) | – |
| Hypertension, n (%) | 18 (36%) | 56 (40%) | 0.59 |
| Diabetes, n (%) | 3 (6%) | 10 (7%) | 0.77 |
| Current smoking, n (%) | 12 (24%) | 13 (9%) | 0.008 |
| Aspirin use, n (%) | 8 (16%) | 44 (32%) | 0.03 |
| Statin use, n (%) | 5 (10%) | 23 (16%) | 0.26 |
| QT-modifying medication use, n (%) | 16 (32%) | 24 (17%) | 0.03 |
| Muscle relaxant, n (%) | 1 (2%) | 8 (6%) | 0.62 |
| Antipsychotics, n (%) | 3 (6%) | 0 | 0.98 |
| Antidepressants, n (%) | 10 (20%) | 23 (17%) | 0.67 |
| Antimicrobials‡, n (%) | 1 (2%) | 2 (10%) | 0.79 |
| Antiemetics, n (%) | 3 (6%) | 3 (2%) | 0.08 |
Characteristics are expressed as n (%), as the mean±SD or as the median (IQR).
*Moderate–severe disease activity is defined as SLEDAI-2K >6 or DAS-28 CRP >3.2.
†n=40.
‡Antimicrobials include macrolides, fluoroquinolones and HIV retrovirals.
Anti-CCP, anticitrullinated cyclic peptide; APS, antiphospholipid antibody syndrome; CRP, C reactive protein; DAS28, Disease Activity Score in 28 joints; DMARD, disease-modifying antirheumatic drug; IL-6, interleukin 6; RA, rheumatoid arthritis; RF, rheumatoid factor; SLE, systemic lupus erythematosus; SLEDAI-2K, Systemic Lupus Erythematosus Disease Activity Index 2000.
Statistically significant p values <0.05 are depicted in bold.