Table 1.
Patient characteristics, stratified by presence of grade 2 leucopenia at least once (ever) during study observation period
| All patients | Leucopoenia—never | Leucopoenia—ever | P-value | |
|---|---|---|---|---|
| (n = 2330) | (n = 1312) | (n = 1018) | ||
| Demographics | ||||
| Age at enrolment, median (IQR), years | 39 (30, 50) | 41 (31, 52) | 38 (29, 48) | <0.001 |
| Age at SLE diagnosis, median (IQR), years | 29 (21, 39) | 30 (22, 41) | 28 (21, 37) | 0.002 |
| Disease duration, median (IQR), years | 8 (3, 14) | 8 (3, 14) | 7 (3, 13) | 0.07 |
| Study observation period, median (IQR), years | 2.3 (1.0, 3.5) | 2.1 (0.7, 3.4) | 2.6 (1.6, 3.7) | <0.001 |
| No. of visits, median (IQR) | 7 (4, 11) | 5 (3, 9) | 9 (5, 12) | <0.001 |
| Visits per study years, median (IQR) | 3.8 (2.6, 4.7) | 3.6 (2.4, 4.7) | 4.0 (2.9, 4.7) | <0.001 |
| Asian ethnicity, n (%) | 2055 (89) | 1173 (90) | 882 (88) | 0.09 |
| Females, n (%) | 2171 (93) | 1218 (93) | 953 (94) | 0.4 |
| Current smoker at enrolment, n (%) | 113 (5.3) | 65 (5.6) | 48 (4.9) | 0.5 |
| Family history of SLE, n (%) | 177 (8.3) | 104 (9.0) | 73 (7.5) | 0.2 |
| Tertiary education, n (%) | 1069 (48) | 609 (49) | 460 (47) | 0.3 |
| Serology, n (%) | ||||
| Low complement (C3/C4) | 1767 (76) | 889 (68) | 878 (87) | <0.001 |
| Anti-dsDNA positivity | 1406 (61) | 698 (53) | 708 (70) | <0.001 |
| ESR ≥25 | 1280 (62) | 636 (56) | 644 (69) | <0.001 |
| Medications use evera, n (%) | ||||
| Prednisolone | 1989 (85) | 1042 (79) | 947 (93) | <0.001 |
| TAM prednisolone, median (IQR), mg/d | 5.3 (2.5, 9.4) | 5.0 (1.1, 7.8) | 7.3 (4.4, 10.3) | <0.001 |
| Anti-malarial drugs | 1734 (74) | 1002 (76) | 732 (72) | 0.014 |
| HCQ | 1612 (69) | 933 (71) | 679 (68) | 0.020 |
| Chloroquine | 167 (7.1) | 92 (7.0) | 74 (7.3) | 0.8 |
| Immunosuppressants | 1661 (71) | 831 (63) | 830 (82) | <0.001 |
| Mycophenolate | 820 (35) | 403 (31) | 417 (41) | <0.001 |
| Mycophenolic acid | 132 (5.7) | 60 (4.6) | 72 (7.1) | 0.010 |
| AZA | 688 (30) | 317 (24) | 371 (36) | <0.001 |
| Ciclosporin | 170 (7.3) | 78 (5.9) | 92 (9.0) | 0.004 |
| MTX | 166 (7.1) | 84 (6.4) | 82 (8.1) | 0.12 |
| Tacrolimus | 88 (3.8) | 35 (2.7) | 53 (5.2) | 0.001 |
| LEF | 66 (2.8) | 29 (2.2) | 37 (3.6) | 0.040 |
| Mizoribine | 13 (0.5) | 3 (0.2) | 10 (1.0) | 0.015 |
| CYC | 229 (11) | 96 (8.2) | 133 (14) | <0.001 |
| Biologics (any) ever | 76 (3.3) | 20 (1.5) | 56 (5.5) | <0.001 |
| Rituximab | 50 (2.4) | 12 (1.0) | 38 (4.0) | <0.001 |
| Belimumab | 31 (1.5) | 9 (0.8) | 22 (2.3) | 0.003 |
| Clinical indicators | ||||
| TAM SLEDAI-2K, median (IQR) | 3.1 (1.5, 5.1) | 2.5 (1.0, 4.5) | 3.7 (2.0, 5.8) | <0.001 |
| SLEDAI ≥ 6 ever, n (%) | 1196 (51) | 584 (44) | 612 (60) | <0.001 |
| TAM PGA, median (IQR) | 0.4 (0.2, 0.8) | 0.4 (0.2, 0.8) | 0.5 (0.3, 0.9) | <0.001 |
| Mild/moderate/severe flare evera, n (%) | 1257 (54) | 606 (46) | 651 (64) | <0.001 |
|
Baseline organ damage present (SDI > 0 at recruitment), n (%) |
916 (39) | 517 (39) | 399 (39) | 0.9 |
| Damage accrual during study period, n (%) | 332 (14) | 154 (12) | 178 (18) | <0.001 |
| Achieved LLDAS evera, n (%) | 1697 (73) | 1004 (77) | 693 (68) | <0.001 |
| Percentage time spent in LLDAS during study period, median (IQR) |
44.6 (0, 76.9) |
50.5 (8.5, 88.3) |
28.9 (0, 58.3) |
<0.001 |
a
Used/achieved at least once during study observation period. P-values for comparing categorical variables were derived using Pearson’s chi-square test. P-values for comparing continuous variables were derived using the Wilcoxon rank-sum test. IQR: interquartile range; LLDAS: lupus low disease activity state; PGA: physician global assessment; TAM: time adjusted mean.