Table 1. Demographics and clinical characteristics of study participants.
| Microarray | Validation | ||||
|---|---|---|---|---|---|
| Active | Active | Active | Active | Inactive | |
| Non-renal | Renal | Non-renal | Renal | Renal | |
| N = 13 | N = 25 | N = 40 | N = 89 | N = 41 | |
| Age: Mean ± SD | 29.4 ± 8.7 | 36.3 ± 10.9 | 31.9 ± 13.2 | 32.8 ± 12.0 | 37.4 ± 13.6 |
| Sex: No. Female (%) | 12 (92.3) | 18 (72) | 36 (90) | 74 (83.1) | 39 (95.1) |
| Ethnicity: Caucasian (%) | 5 (38.5) | 10 (40) | 15 (37.5) | 39 (43.8) | 26 (63.4) |
| Mean Disease Duration (years) | 5.9 ± 5.9 | 6.9 ± 8.1 | 7.8 ± 7.9 | 6.9 ± 7.0 | 14.6 ± 10.1 |
| Mean SLEDAI-2K | 10.9 ± 3.6 | 16.4 ± 8.6 | 9.3 ± 4.0 | 14.4 ± 6.8 | 1.8 ± 1.7 |
| CNS N (%) | 0 (0) | 0 (0) | 0 (0) | 1 (1.1) | 0 (0) |
| Vasculitis | 4 (30.8) | 3 (12) | 12 (30) | 6 (6.7) | 0 (0) |
| Arthritis | 8 (61.6) | 3 (12) | 22 (55) | 16 (18.0) | 0 (0) |
| Myositis | 0 (0) | 1 (4) | 1 (2.5) | 1 (1.1) | 0 (0) |
| Nephritis | 0 (0) | 25 (100) | 0 (0) | 85 (96)a | 2 (4.9)b |
| Rash | 5 (38.5) | 4 (16) | 11 (27.5) | 19 (21.3) | 0 (0) |
| Alopecia | 4 (30.8) | 3 (12) | 10 (25) | 7 (7.9) | 0 (0) |
| Ulcers | 5 (38.5) | 5 (20) | 9 (22.5) | 9(10.1) | 0 (0) |
| Pleuritis | 3 (23.1) | 3 (12) | 5 (12.5) | 8 (9.0) | 0 (0) |
| Pericarditis | 1 (7.7) | 3 (12) | 2 (5) | 7 (7.9) | 0 (0) |
| Low complement | 9 (69.2) | 19 (76) | 24 (60) | 66 (74.2) | 14 (34.1) |
| dsDNA Abs | 11 (84.6) | 20 (80) | 26 (65) | 66 (74.2) | 18 (43.9) |
| Fever | 0 (0) | 0 (0) | 3 (7.5) | 3 (3.4) | 0 (0) |
| Thrombocytopenia | 0 (0) | 1 (4) | 3 (7.5) | 5 (5.6) | 0 (0) |
| Leukopenia | 2 (15.4) | 0 (0) | 6 (15) | 4 (4.5) | 0 (0) |
| Prednisone: N (%) | 6 (46.2) | 21 (84) | 18 (45) | 72 (80.9)c | 26 (63.4) |
| Mean Dose Prednisone | 13.5 ± 16.5 (0–50) | 34.8 ± 26.2 (0–60) | 7.3 ± 12.5 (0–50) | 44.4 ± 94.1 (0–625) | 6.3 ± 7.1 (0–25) |
| Anti-malarials: N (%) | 9 (69.2) | 15 (60) | 26 (65) | 53 (59.6) | 33 (80.5) |
| Immunosuppressives: N(%) | 4 (30.8) | 10 (40) | 14 (35) | 48 (53.9) | 27 (65.9) |
| Azathioprine | 1 (7.7) | 3 (12) | 3 (7.5) | 13 (14.6) | 14 (34.1) |
| Mycophenolate | 1 (7.7) | 7 (28) | 5 (12.5) | 30 (33.7) | 13 (31.8) |
| Methotrexate | 2 (15.4) | 0 | 6 (15) | 1 (1.1) | 0 |
| Cyclosporine | 0 (0) | 0 | 0 (0) | 5 (5.6) | 1 |
| Cyclophosphamide | 0 (0) | 0 | 0 (0) | 2 (2.2) | 0 |
Ten of the active LN and 22 of the active non-LN overlapped between the microarray and NanoString cohorts. Significant differences for patient demographics, mean SLEDAI-2K, and treatment, between active renal and non-renal patients for each cohort are highlighted in bold.
a of the 4 patients with negative renal findings at the time of biopsy, 2 had hematuria, 1 proteinuria, and 1 proteinuria + hematuria prior to the biopsy, as defined by the SLEDAI-2K.
b there were 2 patients with stable proteinuria not attributed to active LN.
c differences in prednisone use between active non-LN and active LN patients were due to the requirement to time the blood draw within ± 2 wks of the renal biopsy for active LN. Most active non-LN patients were recruited at the time of clinic visit and changes in treatment were initiated at the same visit. In contrast, the majority of active LN patients were treated prior to blood draw/renal biopsy (range: 1 day—~ 2 months). 15/17 active LN patients off prednisone had the drug initiated immediately following blood draw/biopsy (the remaining 2 had class V nephritis).