Demographic, clinical and histological characteristics of the patient cohort
| Characteristics | Entire cohort (n=110) | Patient group 1* (n=67) | Patient group 2† (n=30) | Patient group 3‡ (n=8) | Patient group 4§ (n=5) |
| Age at Bx1 (years) | 31 (17–58)¶ | 32.5 (17–56) | 31 (17–49) | 29 (22–47) | 32 (20–58) |
| Female, n (%) | 89 (81)** | 55 (84) | 23 (77) | 7 (87.5) | 3 (60) |
| Duration of follow-up (months) | 109 (34–202) | 107 (35–202) | 135 (40–192) | 111 (101–152) | 48 (34–76) |
| Initial treatment MMF, n (%) | 61 (55) | 37 (55) | 17 (57) | 4 (50) | 4 (80) |
| Initial treatment cyclophosphamide, n (%) | 49 (45) | 30 (45) | 13 (42) | 4 (50) | 1 (20) |
| Serum creatinine at Bx1 (mg/dL) | 0.8 (0.4–4) | 0.9 (0.4–4) | 0.8 (0.5–0.4) | 0.85 (0.6–1.3) | 0.7 (0.5–1.3) |
| Serum creatinine at last follow-up (mg/dL) | 0.7 (0.5–3.4) | 0.7 (0.5–3.0) | 0.7 (0.5–1.3) | 0.7 (0.6–2) | 0.8 (0.5–0.9) |
| Patients progressing to ESKD or death, n (%) | 2 (1.8) ESKD | 2 (3) ESKD | 0 | 1 (12.5) death | 0 |
| Patients with CKD†† at last follow-up, n (%) | 9 (8) | 6 (9) | 0 | 3 (37.5) | 0 |
| Proteinuria at Bx1 (g/day) | 3 (0.4–12) | 3 (0.4–12) | 3.1 (0.6–8) | 4.7 (0.9–9) | 1.2 (0.5–5) |
| Proteinuria at last follow-up (g/day) | 0.2 (0–3) | 0.2 (0–0.8) | 0.3 (0–1.9) | 0.25 (1–3) | 0.2 (0.2–0.5) |
| Anti-dsDNA positive at Bx1, n (%) | 92 (84) | 54 (81) | 26 (87) | 8 (100) | 4 (80) |
| Anti-dsDNA titre at Bx1‡‡ | 500 (80–1280) | 640 (80–1280) | 320 (80–1280) | 960 (160–1280) | 480 (160–640) |
| C3 at Bx1 (mg/dL) | 56 (20–124) | 53 (23–101) | 60 (23–124) | 53 (20–84) | 52 (44–80) |
| C3 low at Bx1, n (%) | 77 (70) | 46 (69) | 20 (67) | 7 (87.5) | 4 (80) |
| C4 at Bx1 (mg/dL) | 8 (1.6–50) | 8 (2–50) | 9 (2–29) | 5.4 (3–27) | 12 (6–15) |
| C4 low at Bx1, n (%) | 68 (62) | 42 (63) | 16 (53) | 7 (87.5) | 2 (40) |
| Bx1 ISN/RPS class III | 29 (26%) | 17 (25.4%) | 5 (16.7%) | 4 (50%) | 3 (60%) |
| Bx1 ISN/RPS class III+V | 10 (9%) | 7 (10.4%) | 3 (10%) | 0 | 0 |
| Bx1 ISN/RPS class IV | 60 (55%) | 34 (50.7%) | 21 (70%) | 3 (37.5%) | 2 (40%) |
| Bx1 ISN/RPS class IV+V | 11 (10%) | 9 (13.4%) | 1 (3.9%) | 1 (12.5%) | 0 |
| Activity index (AI) of Bx1 | 7.5 (1–16) | 8 (2–17) | 7.5 (3–16) | 8 (4–15) | 3 (1–8) |
| Chronicity index of Bx1 | 3 (0–6) | 3 (0–6) | 3 (0–6) | 3 (0–5) | 4 (1–5) |
*Group 1 patients had an AI of 0 on their biopsy done to decide whether immunosuppression could be withdrawn.
†Group 2 patients had an AI >0 on their biopsy done to decide whether immunosuppression could be withdrawn.
‡Group 3 patients had an LN flare after achieving clinical and histological remission.
§Group 4 patients are still being treated and have had only initial and 1-year biopsy.
¶Data presented as median and range.
**Data presented as number of patient and per cent of cohort of subgroup.
††This does not include those patients who have gone on to ESKD.
‡‡Titre only in those patients positive for anti-dsDNA antibodies.
Bx1, biopsy 1; CKD, chronic kidney disease; dsDNA, double-stranded DNA; ESKD, end-stage kidney disease; ISN/RPS, International Society of Nephrology/Renal Pathology Society; LN, lupus nephritis; MMF, mycophenolate mofetil.