Table 1.
Characteristics of the patients. Anti-PF4 antibodies ELISA (Asserachrom HPIA, Diagnostica Stago) with global recognition of immunoglobulins. Interpretation of ELISA result, <30% of reference; negative, 30–50%, borderline positive, >50% positive, >100% strongly positive. IVIG; intravenous immunoglobulin (dose see p. 7–9). Reference values for hemoglobin (male 134–167 g/L and for female 117–155 g/L), platelet count (150–360 × 109/L), PT; prothrombin time (70–130% of normal), fibrinogen (2.0–4.0 g/L) and D-dimer (<0.5 mg/L).
| Patient | 1 | 2 | 3 | 4 | 5 |
|---|---|---|---|---|---|
| Sex | Male | Female | Male | Female | Female |
| Age (years) | 40 | 21 | 58 | 60 | 68 |
| Hospital admission (days after vaccination) | 9 | 12 | 9 | 19 | 16 |
| Medication on admission | Metformin, amlodipin, sertraline, pantoprazole | Insulin, pregabalin, oxycodone | Ezetimibe | Ebastine, salmeterol, fluticasone, estradiol | None |
| Initial anticoagulation (before the VITT diagnosis) | Danaparoid | Tinzaparin | Enoxaparin (ASA, ticagrelor) | Dalteparin | Danaparoid |
| Duration of initial anticoagulation (days) | Continued | 5 | 1 | 22 | Continued |
| Hemoglobin on admission | 147 | 106 | 146 | 116 | 119 |
| Platelet count - nadir | 20 | 46 | 55 | 54 | 68 |
| PT on admission | 73 | 136 | 78 | 116 | 81 |
| Fibrinogen - nadir | 1.0 | 2.3 | 2.1 | 2.7 | 1.5 |
| D-dimer - peak | >128 | 12 | 115 | 5 | 35 |
| Anti-PF antibody positivity (days after vaccination) | 10 | 17 | 10 | 41 | 17 |
| Anti-PF4 antibody level | 109 (strong positive) | 45 (borderline positive) | 96 (positive) | 96 (positive) | 36 (borderline positive) |
| IVIG administration (days after vaccination) | 11 | 22 | 10 | none | 17 |
| Danaparoid treatment started (days after vaccination) | 10 | 19 | 11 | 41 | 17 |
| Outcome | Fatal | Recovery | Recovery | Recovery | Recovery |