Results of the study
| Baseline | Follow-up | p Value | |
|---|---|---|---|
| ISN/RPS class (n) | |||
| I; II (+V) | 0; 0 | 1; 15 (1) | |
| III A (+V); III A/C (+V); III C (+V) | 10 (3); 5 (2); 0 | 0; 9 (1); 8 (2) | |
| IV S A (+V); IV S A/C (+V); IV S C (+V) | 4; 3 (1); 0 | 0; 0; 0 | |
| IV G A (+V); IV G A/C (+V); IV G C (+V) | 9 (3); 11 (1); 0 | 2; 5 (1); 2 | |
| V | 12 | 15 | |
| Glomerular vasculitis | 0 | 1 | |
| Activity Index (mean; median (range)) | 5.7; 5 (0–13, n=64) | 2.3; 2 (0–12, n=63) | <0.001 ↓ (n=63) |
| Chronicity Index (mean; median (range)) | 1.5; 1 (0–6, n=64) | 2.3; 2 (0–8, n=63) | <0.001 ↑ (n=63) |
| SLEDAI-2K (mean; median (range)) | 15.8; 16 (6–28, n=64) | 6.1; 4 (0–23, n=64) | <0.001 ↓ (n=64) |
| PLN cases | 16.3; 16 (6–28, n=52) | 5.4; 4 (0–20, n=52) | <0.001 ↓ (n=52) |
| MLN cases | 13.8; 11.5 (10–23, n=12) | 9; 7 (2–23, n=12) | 0.017 ↓ (n=12) |
| Clinical responders; total; complete; partial (n) | 48; 26; 22 (n=64) | ||
| Histopathological responders; total; complete; partial (n) | 49; 25; 24 (n=63) | ||
| Non-responders; clinical; histopathological (n) | 16 (n=64); 14 (n=63) | ||
| CCR and HCR; CCR and HPR; CCR and HNR (n) | 14; 11; 1 | ||
| CPR and HCR; CPR and HPR; CPR and HNR (n) | 9; 9; 4 | ||
| CNR and HCR; CNR and HPR; CNR and HNR (n) | 2; 4; 9 | ||
| Adverse events after renal biopsies (n (%)) | |||
| Bleeding | 4 (6.3, n=64) | 0 (n=63) | |
| Pain | 4 (6.3, n=64) | 7 (11.1, n=63) | |
| Infection | 0 (n=64) | 0 (n=63) | |
| BLyS levels (ng/mL) (median (range)) | 1.5 (0–6.9, n=64) | 1.7 (0.1–7.6, n=64) | 0.99 (n=64) |
| PLN cases | 1.5 (0–6.9, n=52) | 1.7 (0.6–7.6, n=52) | 0.57 (n=52) |
| MLN cases | 1.5 (0.1–3.1, n=12) | 1.7 (0.1–3.8, n=12) | 0.18 (n=12) |
| Controls | 1.1 (0.4–2, n=64) | ||
| APRIL levels (ng/mL) (median (range)) | 7.1 (0.4–434.3, n=64) | 5.4 (1–286.8, n=64) | <0.001 ↓ (n=64) |
| PLN cases | 7.8 (0.4–333.6, n=52) | 5.6 (1–286.8, n=52) | 0.003 ↓ (n=52) |
| MLN cases | 6.2 (1.8–434.3, n=12) | 3.8 (1.3–36.5, n=12) | 0.006 ↓ (n=12) |
| Controls | 3.6 (0.5–18 589, n=64) | ||
| Anti-dsDNA (IU/mL); positive cases (n (%); median) | 59 (94, n=63); 110 | 48 (79, n=61); 20 | <0.001 ↓ (n=61) |
| Positive PLN cases | 49 (96, n=51); 200 | 41 (84, n=49); 26 | <0.001 ↓ (n=49) |
| Positive MLN cases | 10 (83, n=12); 21 | 7 (58, n=12); 10.5 | 0.33 (n=12) |
| Anti-C1q (U/mL); positive cases (n (%); median) | 46 (73, n=63); 37.2 | 30 (47, n=64); 12.8 | <0.001 ↓ (n=61) |
| Positive PLN cases | 38 (75, n=51); 45.4 | 26 (50, n=52); 13.7 | <0.001 ↓ (n=59) |
| Positive MLN cases | 8 (67, n=12); 21.2 | 4 (33, n=12); 9.9 | 0.060 (n=12) |
The renal biopsies were evaluated according to the ISN/RPS classification system24 and scored for Activity Index and Chronicity Index.25 One patient did not undergo follow-up renal biopsy. The follow-up renal biopsy of another patient was evaluated as a renal vasculitis. Due to data censoring, only the median of autoantibody counts is presented. The lower and upper limits of the assay used for anti-dsDNA counts were 5 IU/mL and 300 IU/mL, respectively. The upper limit of the assay used for estimating anti-C1q levels was 100 U/mL. Cases with anti-dsDNA titre <5 IU/mL were regarded as negative. Cases with anti-C1q titre <14 U/mL were regarded as negative. Statistically significant p values are in bold type. Upward arrows (↑) signify significant increases; downward arrows (↓) signify significant decreases.
Anti-C1q, antibodies to complement component 1q; anti-dsDNA, antibodies to double stranded DNA; APRIL, a proliferation inducing ligand; BLyS, B lymphocyte stimulator; CCR, clinical complete responders; CNR, clinical non-responders; CPR, clinical partial responders; HCR, histopathological complete responders; HNR, histopathological non-responders; HPR, histopathological partial responders; ISN/RPS, International Society of Nephrology/Renal Pathology Society; MLN, membranous lupus nephritis; PLN, proliferative lupus nephritis; SLEDAI-2K, Systemic Lupus Erythematosus Disease Activity Index 2000.26