Variables* | (a) NIH-AI <2 (n=8) | (b) NIH-AI 2–10 (n=12) | (c) NIH-AI >10 (n=12) | (d) No LN (n=47) | (abcd) P value† | (abc) P value | (a) versus (d) P value |
Urine biomarkers‡ and RAIL | |||||||
NGAL (ng/mL) | 3.19 (2.66, 3.6) | 3.89 (3, 4.48) | 3.56 (3.16, 3.78) | 3.59 (3.15, 3.88) | 0.3130 | 0.2413 | 0.2518 |
Ceruloplasmin (ng/mL) | 8.11 (6.66, 9.5) | 9 (8.11, 9.64) | 8.62 (7.63, 9.32) | 3.76 (2.99, 4.98) | <0.0001 | 0.6420 | <0.0001 |
MCP-1 (pg/mL) | 6.34 (5.72, 7.04) | 7.4 (6.79, 7.87) | 8.33 (7.59, 8.84) | 5.9 (4.41, 6.92) | <0.0001 | 0.0103 | 0.3518 |
Adiponectin (ng/mL) | 4.1 (3.79, 4.51) | 4.84 (4.19, 5.89) | 6.28 (4.73, 7.1) | 4.8 (3.6, 5.69) | 0.0096 | 0.0053 | 0.1974 |
Haemopexin (ng/mL) | 7.21 (6.64, 8.13) | 8.38 (7.4, 8.73) | 7.92 (7.54, 8.15) | 6.49 (6.03, 6.89) | <0.0001 | 0.1930 | 0.0378 |
KIM-1 (pg/mL) | 6.8 (5.94, 7.37) | 7.79 (6.71, 8.31) | 7.75 (6.9, 8.5) | 6.27 (4.93, 7.11) | 0.0007 | 0.1866 | 0.3771 |
Urine creatinine (mg/mL) | 0.74 (0.62, 1.48) | 0.79 (0.56, 1.15) | 1.48 (0.74, 2.5) | 1.21 (0.5, 2.07) | 0.3344 | 0.2306 | 0.4034 |
RAIL score | −0.04 (−1.13, 1) | 0.69 (0.09, 1.46) | 2.02 (1.03, 2.68) | −0.21 (−1.69, 1.12) | 0.0027 | 0.0190 | 0.8299 |
RAIL-Cr score | 0.02 (−1.24, 1.01) | 0.9 (0.05, 1.45) | 1.83 (1.08, 2.43) | −0.34 (−1.5, 0.96) | 0.0003 | 0.0176 | 0.6849 |
Traditional LN measures | |||||||
SBP (mm Hg) | 122.5 (110, 127.5) | 125 (115, 136.5) | 122.5 (118.5, 133) | 118 (108, 124) | 0.2008 | 0.6556 | 0.5425 |
DBP (mm Hg) | 63.5 (59.5, 77.5) | 77.5 (68, 89) | 76.5 (66.5, 87) | 70 (61, 75) | 0.1083 | 0.3301 | 0.6946 |
eGFR | 105.5 (90, 146.5) | 97 (49, 128) | 82 (59, 133.5) | 109 (103, 130) | 0.1498 | 0.4488 | 0.5008 |
UPCR | 1.39 (1.05, 3.79) | 4.49 (2.44, 9.21) | 2.17 (0.95, 3.83) | 0.14 (0.09, 0.23) | <0.0001 | 0.0898 | <0.0001 |
UACR | 0.12 (0.07, 0.19) | 0.33 (0.21, 0.48) | 0.63 (0.14, 2.56) | 0.01 (0.01, 0.02) | <0.0001 | 0.0191 | <0.0001 |
NIH-AI | 0.5 (0, 1) | 4.5 (4, 7.5) | 13.5 (12.5, 15) | – | <0.0001 | ||
NIH-CI | 0 (0, 0) | 1.5 (0, 3) | 1 (1, 3) | – | 0.0119 | ||
rSLEDAI score | 4 (2, 10) | 12 (12, 16) | 12 (8, 16) | 0 (0, 0) | <0.0001 | 0.0058 | <0.0001 |
*Values are median (25th, 75th percentile).
†P values are generated from Kruskal-Wallis test.
‡Concentration of urine proteins are natural log transformed.
§Standardisation by urine creatinine.
DBP, diastolic blood pressure; eGFR, estimated glomerular filtration rate as per modified Schwartz formula; KIM-1, kidney injury molecule 1; LN, lupus nephritis; MCP-1, monocyte chemotactic protein 1; NGAL, neutrophil gelatinase-associated lipocalin; NIH-AI, National Institute of Health activity index; NIH-CI, National Institute of Health chronicity index; SBP, systolic blood pressure; UACR, albumin-to-creatinine ratio; UPCR, urine protein-to-creatinine ratio.