Comparison of clinical data, histological characteristics and therapy at first kidney biopsy between patients who had and those who did not have increase in chronicity index between first and second kidney biopsy
| No increase in Chronicity Index (n=17) | Increase in Chronicity Index (n=44) | P value | |
| Male/Female, n* of pts (%) | 2 (12)/ 15 (88) | 4 (9)/ 40 (91) | 0.753 |
| Age at kidney biopsy, years | 27 (24.3–33) | 29 (21.8–36.7) | 0.750 |
| Months between LN diagnosis and biopsy | 2.8 (1–16) | 5 (0.9–37) | 0.280 |
| Months between SLE and biopsy | 24.4 (7–87.6) | 27.7 (4.8–96) | 0.960 |
| Months between first and second biopsy | 29.2 (26.8–64.2) | 54 (27–99.5) | 0.580 |
| Clinical data at first kidney biopsy | |||
| Nephritic syndrome, n* of pts (%) | 3 (17.6) | 21 (47.7) | 0.031 |
| Serum creatinine, mg/dL | 1.1 (0.8–1.3) | 1.1 (0.9–1.6) | 0.169 |
| Serum creatinine ≥1.65 mg/dL, n* of pts (%) | 0 | 10/42 (45)* | 0.027 |
| eGFR, mL/min/1.73 m2 | 67 (57.2–97.6) | 65.7 (42.3–97.6) | 0.369 |
| Proteinuria, g/die | 3.3 (1.5–5.6) | 3.4 (2–5.5) | 0.442 |
| Urinary erythrocytes (number/HPF) | 21.5 (7.8–40) | 17(6-40) | 0.369 |
| Serum C3, mg/dL† | 50 (46-77) | 50 (37-64) | 0.272 |
| Serum C4, mg/dL‡ | 9.5 (5.3–12) | 6 (5-14) | 0.999 |
| Arterial hypertension, n* of pts (%) | 9 (53%) | 23 (52.3%) | 0.963 |
| Therapy | |||
| Methylprednisolone pulses, n* of pts (%) | 11 (68.75%) | 27 (73%) | 0.754 |
| IST Induction, n* of pts (%) Cyclophosphamide | 14 (87.5%) 11 (68.8%) | 25 (65.7%) 15 (40.5%) | 0.130 0.059 |
| Maintenance, (%) MMF/AZA/CSA Na | 9 (53%) 6% / 41% / 6% 0 | 19 (43%) 4.5% / 27% / 11.5% 6 | 0.840 |
| Complete response at 1 year, n* of pts (%) | 8/16 (50%) | 17/40 (42.5%) | 0.610 |
| Kidney flares, n* of pts (%)§ Creatinine flares, n* of pts (%) | 4/17 (23.5%) 0 | 22/41 (53.6%) 9/41 (22%) | 0.035 0.035 |
| Histological characteristic | |||
| Histological classes (%) | |||
| III/IV/V Mixed classes | 17.5/65/17.5 12 | 6.8/82/9 11 | 0.3/0.15/0.3 0.9 |
| Activity index | 6 (3–10) | 7 (6–10) | 0.692 |
| Endocapillary hypercellularity¶>1, pts (%) | 8 (47) | 25 (57.8) | 0.492 |
| Neutrophils infiltration/karyorrhexis¶>1,pts(%) | 6 (35) | 23 (53.3) | 0.233 |
| Cellular/fibrocellular crescents¶>1, pts (%) | 1 (6) | 6 (13.3) | 0.394 |
| Hyaline deposits/wire loops¶>1, pts (%) | 9 (56)** | 25 (57.8) | 0.968 |
| Fibrinoid necrosis††>0, pts (%) | 6 (35) | 23 (51) | 0.234 |
| Interstitial inflammation††>0, pts (%) | 8 (47) | 19 (42.2) | 0.784 |
| Chronicity Index | 2 (1–3) | 1 (0–2) | 0.209 |
| Glomerular sclerosis††>0, pts (%) | 9 (53%) | 16 (35.5%) | 0.238 |
| Fibrous crescents††>0, pts (%) | 10 (59%) | 17 (37.8%) | 0.154 |
| Tubular atrophy††>0, pts (%) | 3 (17.6%) | 7 (17.7%) | 0.869 |
| Interstitial fibrosis††>0, pts (%) | 8 (47%) | 13 (31%) | 0.197 |
P values are evaluated with t-test for independent samples and with χ² test between qualitative or dichotomised variables.
Bold values indicates the significant results.
*10 missing data.
†Normal values 90–180 mg/dL.
‡Normal values 10–40 mg/dL.
§10 missing data (2 data in the group of patients who did not increase Chronicity Index and 8 data in the other group).
¶These variables were categorised as: 0+1 vs 2+3.
** 1 missing data.
††These variables were categorised as: 0 vs 1+2+3, being: 0 if absent; 1+ if mild (in less than 25% of glomeruli and/or in tubulointerstitial cortex); 2+ if moderate (in between 25% and less than 50% of glomeruli and/or in tubulointerstitial cortex) and, 3+ if severe (in more than 50% of glomeruli and/or in tubulointerstitial cortex).
eGFR, estimated glomerular filtration rate; LN, lupus nephritis; MMF, mycophenolate mofetil.