Table 2

Characteristics of patients with different classes of lupus nephritis

PLNMESMLNP value
Patients, n471126
Sex, female (%)948285ns
Age, M (SD)35.5 (14)38.8 (11.8)36.5 (13.5)ns
Disease duration2 (0–5)6.5 (2–15)0 (0–15)ns
First biopsy, n (%)63.836.450.0ns
p-creatinine (µmol/L)68 (55–82)74 (62–83)66 (55.5–94.5)ns
eGFR, mL/min/1.732108 (80–124)98 (77–113)101 (74–128)ns
u-ACR (mg/mmol)52.3 (38–87)20.2 (8–42)26.0 (14–68)0.006
u-ACR ≥50 (mg/mmol), n (%)27 (57.5)2 (18.2)9 (34.5)ns
u-ACR ≥30 (mg/mmol), n (%)38 (80.8)4 (36.4)12 (46.2)ns
Positive a-dsDNA*, %77.045.450.00.005
Low C3†, %78.037.541.50.01
Low C4†, %92.050.041.50.0004
SLEDAI-2K score16 (12–20.5)10 (5.5–13)8 (4–12)<0.0001
LN activity index4 (3–6)1 (1–1)1 (0–2)<0.0001
LN chronicity index0 (0–1)0 (0–2)0.5 (0–2.25)ns
No treatment, n (%)11 (23.4)0 (0.0)12 (46.1)ns
Prednisolone, n (%)34 (72.3)8 (72.7)21 (80.7)ns
Prednisolone (mg*), M (SD)17.2 (14)15.3 (16)12.5 (10)ns
Prednisolone ≥10 mg (%)61.750.047.6ns
Hydroxychloroquine, n (%)21 (44.6)5 (45.4)13 (50.0)ns
DMARD any, n (%)16 (34.0)8 (72.7)15 (57.7)0.04
dt-p-IL-16, n (%)46 (100)10 (100)23 (100)ns
p-IL-16 (ng/mL)0.4 (0.3–0.8)0.61 (0.2–1.7)0.4 (0.26–0.7)ns
p-IL-16 (ng/mL), M (SD)0.69 (0.69)0.86 (0.8)0.67 (0.68)ns
dt-u-IL-16, n (%)32 (68.0)5 (45.4)3 (11.5)<0.0001
u-IL-16 (pg/mL)24 (3‡−58)3‡ (3‡−24)n-dt§<0.0001
u-IL-16 (pg/mL), M (SD)41.9 (51.4)11.2 (10.7)6.8 (12.0)0.0009
  • All variables are presented as median and IQR, if not indicated otherwise.

  • u-ACR >30 corresponds to proteinuria of ≥0.5 g/24 hours).21

  • *Data on a-dsDNA status were missing in 3 of PLN and 6 of MLN.

  • †Data on C3 and C4 status were missing in 10 patients with PLN, 3 MES and 14 MLN.

  • ‡3 is an arbitrary value for non-detectable levels for analysis by non-parametric tests.

  • §Only undetectable levels found in the IQR.

  • ACR, albumin to creatinine ratio; a-dsDNA, anti-double-stranded DNA; DMARD, disease-modifying antirheumatic drugs (detailed information is provided in online supplemental material); dt, detectable (detection limit was defined by ELISA manufacturer’s recommendations as >9 pg/mL); eGFR, glomerular filtration rate; IL, interleukin; LN, lupus nephritis; M, mean; MES, mesangioproliferative lupus nephritis, class II or chronic inactive III; mg, miligram; MN, membranous lupus nephritis, class V; n-dt, non-detectable; p, plasma; PLN, proliferative lupus nephritis, International Society of Nephrology class III, IV+V; SLEDAI-2K, Systemic Lupus Erythematosus Disease Activity Index 2000; u, urine.