Table 1.
Patient demographics
| Variable | Training (n = 41) | Test (n = 23) | Combined (n = 64a) |
|---|---|---|---|
| Age at diagnosis, mean (range) years | 13.9 (7.5–18.1) | 13.7 (9.5–18.1) | 13.8 (7.5–18.1) |
| Sampling date, postdiagnosis (range) days | 15 (0–62) | 5 (0–32) | 12 (0–62) |
| Number (%) females | 37 (90) | 20 (87) | 57 (89) |
| ANA-positive patients (%) | 40 (98) | 23 (100) | 63 (98) |
| dsDNA antibody-positive patients (%) | 35 (83) | 19 (83) | 53 (83) |
| Class III/IV lupus nephritis-biopsy provenb (%) | 23 (56) | 8 (35) | 31 (48) |
| Mean (range) SLEDAI score | 14 (4–30) | 14 (4–29) | 14 (4–30) |
| Treatment at sample: | |||
| PO steroids (%) | 17 (41) | 4 (20) | 21 (33) |
| IV steroids (%) | 18 (44) | 1 (5) | 19 (30) |
| HCQ (%) | 18 (44) | 8 (40) | 26 (41) |
| Other IS (%) | 6 (15) | 0 (0) | 6 (9) |
| None | 10 (24) | 12 (60) | 22 (34) |
| Hispanic (%) | 16 (39) | 9 (39) | 25 (39) |
| Asian/Pacific Islander (%) | 12 (29) | 8 (35) | 20 (31) |
| Non-Hispanic Caucasian (%) | 10 (24) | 5 (22) | 15 (23) |
| Black (%) | 2 (5) | 1 (4) | 3 (5) |
ANA antinuclear antibody, SLEDAI systemic lupus erythematosus disease activity index, PO per os, IV intravenous, HCQ hydroxychloroquine, IS immunosuppressive therapy (cyclophosphamide, mycophenolate, or methotrexate), None no treatment or NSAID alone
aFour new-onset patients who were suspected to have proliferative nephritis, but were not biopsy-confirmed, were not included in the training and test sets, or these demographics. Similarly, two patients with class V nephritis were not included in the training and test sets, or these demographics
bOne patient who developed class IV nephritis 4 years after her initial visit, and a second patient who developed class V nephritis 5 years after her initial visit, were considered negative for this analysis