Baseline characteristics of study participants
| Baseline parameters | Overall (n=400) | COPLA (n=200) | SMT (n=200) | P value |
| Age (in years) | 55.52±1.17 | 54.73±9.48 | 56.31±12.6 | 0.158 |
| Male (n, %) | 269 (67.3%) | 143 (71.5%) | 126 (63%) | 0.088 |
| Chest X-ray change (n, %) | 371 (92.8%) | 186 (93%) | 185 (92.5) | 0.366 |
| BMI (kg/m2) | 23.34±3.34 | 23.6±3.4 | 23.09±3.27 | 0.128 |
| Ordinal scale | 3.22±0.42 | 3.24±0.44 | 3.20±0.41 | 0.396 |
| Respiratory rate (per min) | 28.71±5.5 | 28.8±6.96 | 28.61±3.56 | 0.722 |
| O2 Saturation (in %) | 85.9±3.35 | 85.78±3.37 | 86.03±3.33 | 0.547 |
| PaO2/FiO2 ratio | 145.65±58.63 | 146.44±55.13 | 144.82±62.25 | 0.183 |
| N/L ratio | 13.48±13.39 | 12.69±12.0 | 14.25±14.61 | 0.253 |
| 9.64 (5.19–17.15)* | 9.4 (4.53–17.06)* | 10.5 (5.42–17.76)* | ||
| Ct value | 25.4±5.2 | 25.27±5.35 | 25.52±5.05 | 0.631 |
| SOFA score | 2.61±1.06 | 2.68±1.12 | 2.54±0.99 | 0.228 |
| Serum ferritin (ng/mL) | 618.05±510.59 | 661.34±539.56 | 574.53±477.20 | 0.101 |
| 486 (235.5–833.5)* | 502 (305–878)* | 452.5 (206.25–815.75)* | ||
| D-dimer (mg/L) | 1.08±1.59 | 1.09±1.6 | 1.09±1.5 | 0.996 |
| 0.27 (0.15–1.2)* | 0.25 (0.014–0.89)* | 0.38 (0.18–1.28)* | ||
| CRP (mg/L) | 95.79±77.34 | 94.26±74.13 | 97.33±80.61 | 0.698 |
| 80.9 (32.8–139)* | 81.9 (34.25–130.5)* | 79.65 (31.57–142.75)* | ||
| IL-1 (pg/mL) | 18.08±20.05 | 17.89±17.79 | 18.26±22.15 | 0.866 |
| 9.92 (5.0–24.3)* | 9.7 (5.0–24.77)* | 10.1 (5.0–23.6)* | ||
| IL-6 (pg/mL) | 48.36±89.95 | 51.97±94.32 | 44.75±85.44 | 0.443 |
| 21.9 (9.56–59.5)* | 22.25 (10.8–64.4)* | 20.4 (8.18–58.4)* | ||
| TNF-α (pg/mL) | 15.47±14.16 | 15.41±16.86 | 15.54±10.84 | 0.932 |
| 13.2 (9.56–17.27)* | 12.75 (9.57–16.52)* | 13.55 (9.47–18.52)* | ||
| Neutralising antibodies (mean and proportion %) | 21.6±32.99 | 19.6±31.3 | 23.6±34.5 | 0.522 |
| 130 (32.5%) | 62 (31%) | 68 (34%) | ||
| S1 RBD IgG antibodies (mean and proportion %) | 31.6±81.49 | 24.0±54.84 | 39.2±102.7 | 0.526 |
| 136 (34%) | 65 (32.5%) | 71 (35.5%) |
*Median (IQR) value.
†Data are in mean±SD.
BMI, body mass index; COPLA, COVID-19 convalescent plasma; CRP, C reactive protein; Ct, cycle threshold; FiO2, Fractional inspired oxygen; IL-1, Interleukin-1; IL-6, Interleukin-6; N/L ratio, Neutrophil lymphocyte ratio; O2 Saturation, Oxygen Saturation; PaO2, Partial pressure of oxygen; RBD, receptor-binding domain; SOFA, Sequential Organ Failure Assessment; TNF-α, Tumour necrosis factor α.