Baseline characteristics and final measurements separated according to patient survival
| Characteristics | All cohort (n=150) | Survivors (n=93) | Deceased (n=57) | P value |
| Demographic | ||||
| Age (year), mean (SD) | 42.99 (14.26) | 41.86 (13.51) | 45.36 (14.98) | 0.144 |
| Gender, female, n (%) | 137 (91.33) | 84 (90.32) | 53 (92.98) | 0.574 |
| Disease duration of SLE (year) | 4.00 (0.50–10.00) | 4.00 (0.50–10.00) | 4.50 (0.90–12.25) | 0.815 |
| Disease duration of infection (day) | 10.00 (4.00–15.00) | 10.00 (4.00–16.00) | 7.50 (4.00–14.25) | 0.891 |
| Laboratory findings | ||||
| Leucocyte count (×109/L) | 6.71 (3.85–9.18) | 6.11 (3.69–7.96) | 8.28 (5.19–11.50) | 0.003 |
| Lymphocyte count (×109/L) | 0.55 (0.34–0.91) | 0.64 (0.42–1.03) | 0.47 (0.30–0.71) | 0.004 |
| C reactive protein (mg/L) | 46.73 (10.22–100.88) | 28.43 (6.17–72.97) | 59.36 (29.58–120.97) | 0.002 |
| Procalcitonin (ng/mL) | 0.37 (0.13–1.43) | 0.28 (0.10–0.95) | 0.83 (0.19–2.57) | 0.002 |
| ESR (mm/hour), mean (SD) | 54.52 (37.58) | 58.08 (37.16) | 48.61 (37.87) | 0.159 |
| Albumin (g/L) | 26.70 (22.02–30.87) | 28.20 (23.80–32.60) | 23.30 (20.40–28.10) | <0.001 |
| C3 (g/L) | 0.63 (0.45–0.95) | 0.64 (0.48–0.98) | 0.62 (0.44–0.90) | 0.711 |
| C4 (g/L) | 0.17 (0.08–0.26) | 0.17 (0.08–0.26) | 0.17 (0.08–0.23) | 0.910 |
| SCR (µmol/L) | 78.00 (47.50–142.75) | 68.00 (46.00–113.00) | 98.00 (53.50–219.75) | 0.026 |
| BUN (mmol/L) | 8.60 (5.69–17.77) | 6.80 (5.10–14.30) | 15.58 (7.98–26.86) | <0.001 |
| LAC (mmol/L), mean (SD) | 2.18 (1.18) | 1.99 (0.99) | 2.47 (1.37) | 0.015 |
| BNP ≥400 pg/mL, n (%) | 46 (30.67) | 28 (31.82) | 18 (31.58) | 0.976 |
| SLEDAI score | 8.00 (4.00–12.00) | 7.00 (4.00–11.00) | 9.00 (5.50–13.50) | 0.044 |
| m-SLEDAI score | 6.00 (2.00–9.00) | 5.00 (2.00–8.00) | 8.00 (2.00–10.75) | 0.041 |
| qSOFA score | 0.00 (0.00–1.00) | 0.00 (0.00–1.00) | 1.00 (0.00–1.00) | <0.001 |
| SLICC damage score, mean (SD) | 2.95 (2.51) | 2.62 (2.35) | 3.47 (2.69) | 0.047 |
| Comorbidity, n (%) | ||||
| Congestive heart failure | 21 (14.00) | 14 (15.05) | 7 (12.50) | 0.664 |
| Diabetes mellitus | 26 (17.33) | 14 (15.05) | 12 (21.43) | 0.321 |
| Chronic kidney disease* | 49 (32.67) | 27 (29.03) | 22 (39.29) | 0.197 |
| Stroke | 11 (7.33) | 3 (3.23) | 8 (14.29) | 0.012 |
| Hypertension | 32 (21.48) | 18 (19.35) | 14 (25.00) | 0.416 |
| COPD | 11 (7.33) | 7 (7.53) | 4 (7.02) | 0.908 |
| SLE organ system involvement†, n (%) | ||||
| Lupus nephritis | 86 (57.33) | 49 (52.69) | 37 (66.07) | 0.109 |
| Neuropsychiatric lupus | 29 (19.33) | 13 (13.98) | 16 (28.57) | 0.029 |
| Interstitial lung disease | 19 (12.67) | 12 (12.90) | 7 (12.50) | 0.943 |
| Pulmonary hypertension | 27 (18.00) | 17 (18.28) | 10 (17.86) | 0.948 |
| Musculoskeletal and skin | 50 (33.33) | 32 (34.41) | 18 (31.58) | 0.721 |
| Cytopenia | 77 (51.33) | 50 (53.76) | 27 (47.37) | 0.447 |
| Serositis | 56 (37.33) | 40 (43.01 | 16 (28.07) | 0.066 |
| Infection site, n (%) | ||||
| Pulmonary infection | 119 (79.33) | 71 (76.34) | 48 (84.21) | 0.248 |
| Bloodstream infection | 31 (20.67) | 14 (15.05) | 17 (29.82) | 0.030 |
| Central nervous system infection | 10 (6.67) | 6 (6.45) | 4 (7.02) | 0.893 |
| Gastrointestinal infection | 6 (4.00) | 3 (3.23) | 3 (5.26) | 0.537 |
| Urinary tract infection | 6 (4.00) | 3 (3.23) | 3 (5.26) | 0.537 |
| Osteoarticular infection | 6 (4.00) | 5 (5.38) | 1 (1.75) | 0.272 |
| Pelvic infection | 6 (4.00) | 4 (4.30) | 2 (3.51) | 0.810 |
| Medication history‡, n (%) | ||||
| Maximum prednisone-equivalent dose ≥60 mg/day | 97 (66.44) | 51 (56.67) | 46 (83.64) | <0.001 |
| ≥250 mg/day | 42 (28.77) | 24 (26.67) | 18 (32.14) | 0.477 |
| ≥500 mg/day | 24 (16.44) | 13 (14.44) | 11 (19.64) | 0.410 |
| Immunosuppressant§ | 88 (58.67) | 50 (53.76) | 38 (67.86) | 0.090 |
| Hydroxychloroquine | 83 (55.33) | 58 (62.37) | 25 (43.86) | 0.027 |
| Methotrexate | 8 (5.33) | 6 (6.45) | 2 (3.51) | 0.711 |
| Azathioprine | 6 (4.00) | 4 (4.30) | 2 (3.51) | 0.810 |
| Cyclophosphamide | 30 (20.00) | 18 (19.35) | 12 (21.05) | 0.801 |
| Mycophenolate mofetil | 34 (22.67) | 15 (16.13) | 19 (33.33) | 0.015 |
| Ciclosporin | 19 (12.67) | 8 (8.60) | 11 (19.30) | 0.056 |
| Rituximab | 10 (6.67) | 6 (6.45) | 4 (7.02) | 0.893 |
Data are presented as median (IQR) unless otherwise noted.
*Chronic kidney disease was defined as serum creatinine measurements above the upper reference value over a 3-month or greater period.
†Organ involvement in SLE was representative of the current status at inclusion.
‡The usage of these drugs was assessed from inclusion in the study to the past 6 months.
§Immunosuppressant use was identified as treatment with any of methotrexate, azathioprine, cyclophosphamide, mycophenolate mofetil, ciclosporin and rituximab.
BUN, blood urea nitrogen; COPD, chronic obstructive pulmonary diseas; ESR, erythrocyte sedimentation rate; LAC, lactate; m-SLEDAI, modified SLE Disease Activity Index; qSOFA, quick Sequential Organ Failure Assessment; SCR, serum creatinine; SLICC, Systemic Lupus International Collaborating Clinics.