Clinical and laboratory features based on ANCA specificity
| ANCA (+) (n=49) | ANCA (−) (n=1279) | p Value | |
| Men | 9 (18.37) | 181 (14.15) | 0.408 |
| Age, years | 33 (26–40) | 30 (22–37) | 0.116 |
| Duration of LN, months | 3.77 (1.18–15.97) | 5.27 (1.80–22.20) | 0.186 |
| SLEDAI, score | 14 (12–18) | 12 (10–16) | <0.001 |
| Hypertension | 15 (30.61) | 363 (28.38) | 0.734 |
| Proteinuria, g/24 hours | 2.81 (1.11–5.04) | 2.29 (1.12–4.35) | 0.247 |
| Urinary RBC count, ×104/mL | 101 (25–525) | 43 (5–176) | 0.006 |
| SAlb, g/L | 27.40 (21.55–32.65) | 27.90 (22.40–33.40) | 0.492 |
| SCr, μmol/L | 91.05 (74.26–147.63) | 73.37 (54.81–101.66) | <0.001 |
| eGFR, mL/min/per 1.73 m2 | 68.67 (44.01–96.86) | 98.36 (65.48–122.60) | <0.001 |
| <60 mL/min/per 1.73 m2 | 21 (42.86) | 284 (22.20) | 0.001 |
| <30 mL/min/per 1.73 m2 | 4 (8.16) | 112 (8.76) | 0.900 |
| C3, g/L | 0.42 (0.34–0.66) | 0.47 (0.36–0.68) | 0.181 |
| C4, g/L | 0.09 (0.06–0.16) | 0.11 (0.06–0.17) | 0.457 |
Values are given as n (%) or median (IQR).
ANCA, anti-neutrophil cytoplasmic antibody; C3, complement 3; C4, complement 4; eGFR, estimated glomerular filtration rate; LN, lupus nephritis; RBC, red blood cell; SAlb, serum albumin; SCr, serum creatinine; SLEDAI, systemic lupus erythematosus disease activity index.