Risk factors for renal relapse at inclusion (per-protocol population)
| Relapse (N=17) | No relapse (N=67) | P value | |
| Mean (SD) N (%) | Mean (SD) N (%) | ||
| Age, years | 32.4 (11.7) | 38.3 (13.8) | 0.111 |
| Sex, female | 17 (100.0) | 54 (80.6) | 0.061 |
| Ethnicity | 0.395 | ||
| Caucasian | 9 (52.9) | 44 (65.7) | – |
| Black | 5 (29.4) | 18 (26.9) | – |
| Asian | 3 (17.6) | 5 (7.5) | – |
| SLE disease duration, years | 8.1 (5.9) | 8.7 (8.9) | 0.764 |
| Antiphospholipid syndrome | 5 (29.4) | 6 (9.0) | 0.041 |
| Menopause | 1 (5.9) | 15/52 (28.8) | 0.094 |
| Obesity | 2 (11.8) | 9 (13.4) | 1.00 |
| First flare of proliferative LN | 12 (70.6) | 52 (77.6) | 0.537 |
| Induction therapy with: | 0.947 | ||
| Intravenous cyclophosphamide | 10 (58.8) | 40 (59.7) | |
| Mycophenolate mofetil | 7 (41.2) | 27 (40.3) | |
| Maintenance IST duration at M0, years | 2.6 (1.0) | 2.9 (0.7) | 0.231 |
| Maintenance IST | 0.753 | ||
| Mycophenolate mofetil | 13 (76.5) | 53 (79.1) | – |
| Azathioprine | 4 (23.5) | 14 (20.9) | – |
| Doses prescribed at M0, mg/day | |||
| Mycophenolate mofetil | 1500.0 (277.3) | 1510.2 (639.3) | 0.956 |
| Azathioprine | 75.0 (28.9) | 82.7 (35.9) | 0.676 |
| Corticosteroids | 4.8 (3.3) | 4.1 (2.6) | 0.436 |
| Hydroxychloroquine | 332 (142) | 354 (105) | 0.455 |
| Serum hydroxychloroquine level, ng/L | 787 (494) | 722 (598) | 0.464 |
| Serum hydroxychloroquine level <200 ng/L | 2/15 (13.3) | 12/53 (22.6) | 0.719 |
| Serum creatinine, µmol/L | 63.8 (10.4) | 71.9 (17.0) | 0.052 |
| Estimated GFR, mL/min/1.73 m² | 107.2 (24.0) | 95.8 (27.3) | 0.046 |
| Chronic kidney disease stage | 0.134 | ||
| Stage 1 | 14 (82.4) | 38 (56.7) | – |
| Stage 2 | 2 (11.8) | 24 (35.8) | – |
| Stage 3 | 1 (5.9) | 5 (7.5) | – |
| Urinary protein/creatinine ratio, g/g | 0.548 (0.550) | 0.169 (0.187) | 0.001 |
| Urinary protein/creatinine ratio ≤0.2 g/g | 5 (29.4%) | 50 (74.6%) | <0.001 |
| Urinary protein/creatinine ratio ≤0.5 g/g | 12 (70.6) | 64 (95.5) | 0.007 |
| Urinary protein/creatinine ratio ≤0.7 g/g | 12 (70.6) | 66 (98.5) | 0.001 |
| Serum albumin, g/dL | 3.9 (0.4) | 4.3 (0.4) | 0.004 |
| Haemoglobin level, g/L | 1.19 (0.14) | 1.32 (0.14) | 0.003 |
| Leucocyte count, g/L | 4.8 (2.4) | 5.8 (1.9) | 0.011 |
| Neutrophil count, g/L | 3.3 (2.4) | 3.8 (1.9) | 0.204 |
| Lymphocyte count, g/L | 1.0 (0.4) | 1.5 (0.6) | 0.003 |
| Basophil count, g/L | 0.01 (0.01) | 0.02 (0.02) | 0.128 |
| Eosinophil count, g/L | 0.04 (0.04) | 0.10 (0.14) | 0.049 |
| Platelet count, g/L | 289 (130) | 237 (65) | 0.109 |
| Low C3 | 6/16 (37.5) | 4/64 (6.3) | 0.003 |
| Low C4 | 3/16 (18.8) | 4/64 (7.8) | 0.194 |
| Positive anti-dsDNA | 13 (76.5) | 36 (53.8) | 0.092 |
| SLEDAI score | 3.1 (2.6) | 1.6 (1.4) | 0.025 |
Data are expressed as % or mean (SD). In the case of missing data, the number/number available (%) is indicated.
GFR, glomerular filtration rate; IST, immunosuppressive therapy; LN, lupus nephritis; SLE, systemic lupus erythematosus; SLEDAI, SLE Disease Activity Index.