Patient characteristics
| Characteristic . | Patients with COVID-19 . | |
|---|---|---|
| Without thrombosis . | With thrombosis* . | |
| No. of patients | 212 (100) | 10 (100) |
| Sex | ||
| Female | 93 (43.8) | 4 (40.0) |
| Male | 119 (56.2) | 6 (60.0) |
| Age, y | ||
| Median (range) | 55 (0.4-88) | 55 (23-84) |
| <60 | 146 (68.9) | 6 (60.0) |
| ≥60 | 66 (31.1) | 4 (40.0) |
| Outpatient care | 61 (28.8) | 0 |
| Hospitalization | 151 (71.2) | 10 (100) |
| General ward (% of all patients) | 122 (57.5) | 8 (80.0) |
| Intensive care unit (% of all patients) | 29 (13.7) | 2 (20.0) |
| WHO COVID-19 score | ||
| 1-3 | 87 (41.0) | 3 (30.0) |
| 4-5 | 105 (49.5) | 5 (50.0) |
| 6-9 | 18 (8.5) | 2 (20.0) |
| 10 | 2 (0.95) | 0 |
| Interval from symptoms to blood drawing, d | ||
| 0-10 | 115 (54.2) | 4 (40.0) |
| 11-20 | 55 (25.9) | 5 (50.0) |
| 21-50 | 37 (17.5) | 1 (10.0) |
| >50 | 5 (2.4) | |
| Mean platelet count at time of blood drawing × 109/L (range) | 239 (24-769) | 223 (82-364) |
| No. of patients with platelet count (× 109/L) | ||
| >150 | 178 (83.9) | 7 (70.0) |
| >100-150 | 24 (11.3) | 2 (20.0) |
| 50 to ≤100 | 7 (3.3) | 1 (10.0) |
| <50 | 1 (0.47) | 0 |
| Missing data | 2 (0.94) | |
| Heparin treatment (≥5 d) before blood drawing | 32 (15.0) | 3 (30.0) |
| Missing data | 2 (0.94) | 0 |
| PF4-heparin ELISA OD | ||
| <0.5 | 194 (91.5) | 9 (90.0) |
| ≥0.5 to <1.0 | 13 (6.1) | 0 |
| ≥1.0 | 5 (2.4) | 1 (10.0) |
| Heparin-dependent platelet activation, (sera with PF4-heparin ELISA OD ≥0.5) | ||
| Negative | 18 (8.5) | 10† |
| Positive | 0 | 0 |
| PF4-dependent platelet activation (sera with PF4-heparin ELISA OD ≥0.5) | ||
| Negative | 14 (6.6) | 10† |
| Positive | 4 (1.9) | 0 |
| Outcome | ||
| Survived | 206 (97.2) | 10 (100) |
| In-hospital deaths | 6 (2.8) | 0 |
| Characteristic . | Patients with COVID-19 . | |
|---|---|---|
| Without thrombosis . | With thrombosis* . | |
| No. of patients | 212 (100) | 10 (100) |
| Sex | ||
| Female | 93 (43.8) | 4 (40.0) |
| Male | 119 (56.2) | 6 (60.0) |
| Age, y | ||
| Median (range) | 55 (0.4-88) | 55 (23-84) |
| <60 | 146 (68.9) | 6 (60.0) |
| ≥60 | 66 (31.1) | 4 (40.0) |
| Outpatient care | 61 (28.8) | 0 |
| Hospitalization | 151 (71.2) | 10 (100) |
| General ward (% of all patients) | 122 (57.5) | 8 (80.0) |
| Intensive care unit (% of all patients) | 29 (13.7) | 2 (20.0) |
| WHO COVID-19 score | ||
| 1-3 | 87 (41.0) | 3 (30.0) |
| 4-5 | 105 (49.5) | 5 (50.0) |
| 6-9 | 18 (8.5) | 2 (20.0) |
| 10 | 2 (0.95) | 0 |
| Interval from symptoms to blood drawing, d | ||
| 0-10 | 115 (54.2) | 4 (40.0) |
| 11-20 | 55 (25.9) | 5 (50.0) |
| 21-50 | 37 (17.5) | 1 (10.0) |
| >50 | 5 (2.4) | |
| Mean platelet count at time of blood drawing × 109/L (range) | 239 (24-769) | 223 (82-364) |
| No. of patients with platelet count (× 109/L) | ||
| >150 | 178 (83.9) | 7 (70.0) |
| >100-150 | 24 (11.3) | 2 (20.0) |
| 50 to ≤100 | 7 (3.3) | 1 (10.0) |
| <50 | 1 (0.47) | 0 |
| Missing data | 2 (0.94) | |
| Heparin treatment (≥5 d) before blood drawing | 32 (15.0) | 3 (30.0) |
| Missing data | 2 (0.94) | 0 |
| PF4-heparin ELISA OD | ||
| <0.5 | 194 (91.5) | 9 (90.0) |
| ≥0.5 to <1.0 | 13 (6.1) | 0 |
| ≥1.0 | 5 (2.4) | 1 (10.0) |
| Heparin-dependent platelet activation, (sera with PF4-heparin ELISA OD ≥0.5) | ||
| Negative | 18 (8.5) | 10† |
| Positive | 0 | 0 |
| PF4-dependent platelet activation (sera with PF4-heparin ELISA OD ≥0.5) | ||
| Negative | 14 (6.6) | 10† |
| Positive | 4 (1.9) | 0 |
| Outcome | ||
| Survived | 206 (97.2) | 10 (100) |
| In-hospital deaths | 6 (2.8) | 0 |
All data are n (%), unless otherwise indicated. Data were collected from 5 university hospitals: Munich, n = 55; Freiburg, n = 42; Tübingen, n = 32; Greifswald, n = 32; Bari, n = 61.
Thrombosis localization: pulmonary embolism, 6; stroke, 1; portal vein, 2; unknown, 1.
All sera from patients with thrombosis were tested independently of the PF4-heparin ELISA result.