Table 2.
Baseline demographics and patient characteristics
| Characteristic | LN patient population (N=176) | |
|---|---|---|
| Continuous variables | Mean (SD) | Median (min, max) |
|
| ||
| Age at biopsy date (Day 0; years) | 36.1 (11.81) | 35.0 (18.00, 76.00) |
| Serum creatinine (mg/dL) | 1.0 (0.63) | 0.8 (0.40, 4.70) |
| Urinary creatinine (mg/dL) | 135.7 (110.15) | 109.0 (27.00, 655.00) |
| Urinary protein:creatinine ratio | 1.5 (1.80) | 0.8 (0, 9.91) |
| Urinary RBC (RBC/hpf) | 8.6 (20.07) | 2.5 (0, 100.00) |
| SLICC Damage Index score | 2.2 (2.61) | 1.0 (0, 12.00) |
|
| ||
| Categorical variables | n (%) | |
|
| ||
| LN ISN category | III | 44 (25.0) |
| IV | 51 (29.0) | |
| V | 40 (22.7) | |
| Mixed | 41 (23.3) | |
|
| ||
| Initiated induction therapy in 6 months before or after biopsy date | CYC | 28 (15.9) |
| MMF | 88 (50.0) | |
| AZA | 17 (9.7) | |
| RTX | 0 | |
| None | 43 (24.4) | |
| CYC or MMF or AZA or RTX | 133 (75.6) | |
|
| ||
| Decade of biopsy | 1989 or earlier | 2 (1.1) |
| 1990–1999 | 36 (20.5) | |
| 2000–2009 | 123 (69.9) | |
| 2010–2013 | 15 (8.5) | |
|
| ||
| Gender | Female | 161 (91.5) |
|
| ||
| Race/ethnicity | Black | 94 (53.4) |
| Other | 82 (46.6) | |
|
| ||
| Urine protein dipstick* (semi-quantitative) category | 0 | 18 (10.2) |
| 0.5 | 12 (6.8) | |
| 1 | 23 (13.1) | |
| 2 | 48 (27.3) | |
| 3 | 63 (35.8) | |
| 4 | 11 (6.3) | |
| 5 | 0 | |
|
| ||
| Hypertension** | 138 (78.4) | |
|
| ||
| Diabetes*** | 29 (16.5) | |
|
| ||
| History of MI | 4 (2.3) | |
|
| ||
| Any hydroxychloroquine use from Day 0 to Month 24 | 123 (69.9) | |
| Any prednisone use from Day 0 to Month 24 | 164 (93.2) | |
AZA, azathioprine; CYC, cyclophosphamide; ISN, International Society of Nephrology; LN, lupus nephritis; MI, myocardial infarction; MMF, mycophenolate mofetil; RBC/hpf, red blood cells per high power field; RTX, rituximab; SD, standard deviation; SDI, SLICC damage index; SLICC, Systemic Lupus Collaborating Clinics
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
Defined as systolic blood pressure ≥140 or diastolic blood pressure ≥90 mmHg on two or more occasions OR hypertension recorded as part of the SDI at any clinic visit
Renal biopsy established that proteinuria was lupus-related and not diabetes-related