Table 2.
Characteristics of patients with different classes of lupus nephritis
| PLN | MES | MLN | P value | |
| Patients, n | 47 | 11 | 26 | |
| Sex, female (%) | 94 | 82 | 85 | ns |
| Age, M (SD) | 35.5 (14) | 38.8 (11.8) | 36.5 (13.5) | ns |
| Disease duration | 2 (0–5) | 6.5 (2–15) | 0 (0–15) | ns |
| First biopsy, n (%) | 63.8 | 36.4 | 50.0 | ns |
| p-creatinine (µmol/L) | 68 (55–82) | 74 (62–83) | 66 (55.5–94.5) | ns |
| eGFR, mL/min/1.732 | 108 (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*, % | 77.0 | 45.4 | 50.0 | 0.005 |
| Low C3†, % | 78.0 | 37.5 | 41.5 | 0.01 |
| Low C4†, % | 92.0 | 50.0 | 41.5 | 0.0004 |
| SLEDAI-2K score | 16 (12–20.5) | 10 (5.5–13) | 8 (4–12) | <0.0001 |
| LN activity index | 4 (3–6) | 1 (1–1) | 1 (0–2) | <0.0001 |
| LN chronicity index | 0 (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 (%) | 61.7 | 50.0 | 47.6 | ns |
| 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.