Patient demographics and baseline clinical characteristics
| Characteristic | mPERR response (N=114) | No mPERR response (N=59) | Total (N=173) | |||
| Continuous variables | Mean (SD) | Median (min, max) | Mean (SD) | Median (min, max) | Mean (SD) | Median (min, max) |
| Age at biopsy date | 37.0 (11.7) | 36.0 (18.0, 66.0) | 34.8 (12.0) | 33.0 (18.0, 76.0) | 36.2 (11.8) | 35.0 (18.0, 76.0) |
| Serum creatinine (mg/dL) | 0.9 (0.4) | 0.8 (0.4, 3.0) | 1.1 (0.8) | 0.8 (0.4, 4.7) | 1.0 (0.6) | 0.8 (0.4, 4.7) |
| Urinary creatinine (mg/dL) | 132.2 (97.5) | 108.5 (27.0, 505.0) | 147.1 (147.3) | 110.0 (29.0, 655.0) | 135.7 (110.2) | 109.0 (27.0, 655.0) |
| Urinary RBC (RBC/hpf) | 9.9 (22.6) | 2.3 (0.0, 100.0) | 6.1 (14.1) | 2.5 (0.0, 100.0) | 8.6 (20.2) | 2.5 (0.0, 100.0) |
| SDI | 1.9 (2.4) | 1.0 (0.0, 10.0) | 2.6 (3.0) | 1.0 (0.0, 12.0) | 2.2 (2.6) | 1.0 (0.0, 12.0) |
| uPCR | 1.2 (1.8) | 0.5 (0.0, 9.9) | 2.6 (1.5) | 2.7 (0.5, 5.6) | 1.5 (1.8) | 0.8 (0.0, 9.9) |
| Categorical variables | n (%) | n (%) | n (%) |
| Female | 104 (91.2) | 54 (91.5) | 158 (91.3) |
| Race | |||
| Black African ancestry | 55 (48.3) | 36 (61.0) | 91 (52.6) |
| Other | 59 (51.8) | 23 (39.0) | 82 (47.4) |
| LN ISN category | |||
| III | 32 (28.1) | 12 (20.3) | 44 (25.4) |
| IV | 29 (25.4) | 21 (35.6) | 50 (28.9) |
| V | 29 (25.4) | 10 (17.0) | 39 (22.5) |
| Mixed | 24 (21.1) | 16 (27.1) | 40 (23.1) |
| IS use at baseline (3 months before or after biopsy date) | |||
| Any IS use | 92 (80.7) | 51 (86.4) | 143 (82.7) |
| CYC | 19 (16.7) | 9 (15.3) | 28 (16.2) |
| MMF | 55 (48.2) | 32 (54.2) | 87 (50.3) |
| AZA | 8 (7.0) | 9 (15.3) | 17 (9.8) |
| IS type unknown | 10 (8.8) | 1 (1.7) | 11 (6.4) |
| None | 22 (19.3) | 8 (13.5) | 27 (15.6) |
| Missing* | 1 (0.9) | 2 (3.3) | 3 (1.7) |
| Decade of biopsy | |||
| 1989 or earlier | 0 (0.0) | 2 (3.4) | 2 (1.2) |
| 1990–1999 | 23 (20.2) | 12 (20.3) | 35 (20.2) |
| 2000–2009 | 79 (69.3) | 43 (72.9) | 122 (70.5) |
| 2010–2013 | 12 (10.5) | 2 (3.4) | 14 (8.1) |
| Available proteinuria measures at baseline (3 months before or after biopsy date) | |||
| uPCR | NA | NA | 69 (39.9) |
| 24-hour urine protein | NA | NA | 92 (53.2) |
| Urine protein dipstick | NA | NA | 173 (100.0) |
| Proteinuria at baseline (3 months before or after biopsy date)† | |||
| <0.5 | NA | NA | 21 (12.1) |
| ≥0.5 | NA | NA | 152 (87.9) |
| ≤0.7‡ | NA | NA | 27 (19.9) |
| Urine protein dipstick§ (semi-quantitative) category | |||
| 0 | 13 (11.4) | 4 (6.8) | 17 (9.8) |
| 0.5 | 10 (8.8) | 2 (3.4) | 12 (6.9) |
| 1 | 22 (19.3) | 1 (1.7) | 23 (13.3) |
| 2 | 32 (28.1) | 16 (27.1) | 48 (27.8) |
| 3 | 33 (29.0) | 29 (49.2) | 62 (35.8) |
| 4 | 4 (3.5) | 7 (11.9) | 11 (6.4) |
| 5 | 0 (0.0) | 0 (0.0) | 0 (0.0) |
| Hypertension¶ | 88 (77.2) | 47 (79.7) | 135 (78.0) |
| Diabetes | 13 (11.4) | 14 (23.7) | 27 (15.6) |
| History of MI | 1 (0.9) | 3 (5.1) | 4 (2.3) |
| Any hydroxychloroquine use from baseline to 2 years post biopsy | 85 (74.6) | 35 (59.3) | 120 (69.4) |
*Refers to patients where IS use was missing or not captured within the time period window at baseline (in the 3 months before or after the biopsy date) within the study database.
†Proteinuria measurement data were selected using a hierarchical approach, with uPCR as the first choice, followed by 24-hour urine protein (g/24 h) and lastly, semi-quantitative urine dipstick measures were used, if others not available.
‡Based on uPCR or 24-hour urine protein measurements only, as dipstick test could not assess measures from >0.5 to <3 due to the semi-quantitative nature of the test. These data were available for 136 patients.
§Dipstick results were selected for the purposes of describing the cohort at baseline, as this particular method of measuring proteinuria was complete for all patients during the baseline window. Dipstick scores of 0–1 were equivalent to urine protein of <0.5 g/24 h; dipstick scores of 2–4 were equivalent to urine protein of ≥0.5 g/24 h.
¶Defined as systolic blood pressure ≥140 or diastolic blood pressure ≥90 mm Hg on two or more occasions OR hypertension recorded as part of the SDI at any visit from day 0 to 2 years post biopsy.
ACR, American College of Rheumatology; AZA, azathioprine; CYC, cyclophosphamide; IS, immunosuppressive; ISN, International Society of Nephrology; LN, lupus nephritis; MI, myocardial infarction; MMF, mycophenolate mofetil; mPERR, modified primary efficacy renal response; NA, not available; RBC/hpf, red blood cells per high power field; SD, standard deviation; SDI, SLICC/ACR damage index; SLICC, Systemic Lupus Collaborating Clinics; uPCR, urinary protein:creatinine ratio.