Baseline characteristics of 165 patients with childhood-onset SLE*
| Variables | Total cohort (N=165) | LN group (N=45) | No-LN group (N=120) | P value LN group versus no-LN group† |
| Demographics | ||||
| Female gender | 137 (83) | 37 (82) | 100 (83%) | 0.87 |
| White race | 95 (58) | 18 (40) | 77 (64) | 0.03 |
| Hispanic ethnicity | 5 (3.0) | 1 (2.2) | 4 (3.3) | 0.77 |
| Age at diagnosis (years) | 13 (12, 15) | 13 (12, 14) | 14 (12, 15) | 0.39 |
| Disease duration at baseline (years) | 0 (0, 1) | 0 (0, 2) | 0 (0, 1) | 0.06 |
| Follow-up duration (years) | 4 (2, 5) | 4 (3, 6) | 3 (2, 5) | 0.03 |
| Weight (kg) | 56.5 (46.8, 63.6) | 58.65 (50, 63.7) | 56 (45.5, 63.6) | 0.35 |
| Medication use | ||||
| Hydroxychloroquine | 132 (80) | 36 (80) | 96 (80) | 1.00 |
| Minimal oral prednisone use | 105 (64) | 20 (44) | 85 (71) | 0.0017 |
| Intravenous methylprednisolone use | 11 (6.7) | 3 (6.7) | 8 (6.7) | 1.00 |
| Oral prednisone dose (mg/day) | 0 (0, 15) | 10 (0, 30) | 0 (0, 10) | 0.0021 |
| Oral weight-adjusted prednisone dose (mg/kg/day) | 0 (0, 0.32) | 0.24 (0, 0.79) | 0 (0, 0.16) | 0.0014 |
| Immunosuppressants† | 45 (27) | 14 (31) | 31 (26) | 0.50 |
| Disease activity/damage | ||||
| SLEDAI-2K score* | 4 (1, 8) | 9 (4, 18) | 2 (0, 4.5) | <0.0001 |
| SDI score* | 0 (0, 0) | 0 (0, 0) | 0 (0, 0) | 0.096 |
| SDI score=0 (%) | 141 (86) | 35 (78) | 106 (88) | 0.087 |
| T2T state | ||||
| Presence of SLEDAI-LD | 105 (64) | 15 (33) | 90 (75) | <0.0001 |
| Use of low-CS | 103 (62) | 20 (44) | 83 (69) | 0.0035 |
| Presence of LLDAS | 48 (29) | 7 (16) | 41 (34) | 0.0191 |
| Any of the T2T states | 131 (79) | 27 (60) | 104 (87) | 0.0002 |
*Values are n (%) or median (25th, 75th percentile) unless stated otherwise; Wilcoxon two-sample test was used for continuous variables, and χ2 test was used for categorical variables.
†Immunosuppressants were cyclophosphamide; mycophenolate mofetil; methotrexate, azathioprine, cyclosporine and leflunomide; rituximab, tocilizumab, abatacept and belimumab.
CS, corticosteroid; LLDAS, lupus low disease activity state; LN, lupus nephritis; low-CS, limited corticosteroid use; SDI, Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index; SLEDAI-2K, SLE Disease Activity Index V.2K; SLEDAI-LD, SLEDAI score of <4; T2T, treat-to-target.