Clinical parameters and VITT diagnostic results of VITT-positive samples
| Patient . | Platelet nadir (×109/L) . | Clinical symptoms . | Symptoms onset (no. of days after vaccination) . | Anti-PF4-heparin IgG ELISA (OD)* . | PF4-dependent platelet-activation assay (activated cells)† . | IvIgG prior blood withdrawal . | MAIPA‡ . | ||
|---|---|---|---|---|---|---|---|---|---|
| GPIIb/IIIa antibodies . | GPIb/IX antibodies . | GPIa/IIa antibodies . | |||||||
| Female, 40 y | 36 | Initially with severe headache and nausea, 5 d later CSVT | 6 | 2.94 | Positive | No | 0.145 | 0.12 | 1.915 |
| Female, 57 y | 24 | CSVT | 3 | 2.87 | Positive | No | 0.19 | 0.245 | 0.09 |
| Female, 61 y | 50 | Flu-like symptoms with headache and fever | 9 | 3.2 | Positive | Yes | 0.25 | 0.305 | 0.44 |
| Male, 20 y | 99 | Initially with headache, later pulmonary embolism and CSVT | Not known | 3.56 | Positive | Yes | 0.2 | 0.21 | 0.235 |
| Male, 21 y | 94 | Initially with headache, later CSVT | ∼2 | 3.12 | Positive | No | 0.18 | 0.265 | 0.34 |
| Female, 61 y | 46 | Initially with headache, later dissection of the A. vertebralis and infarct of the medulla oblongata. | 11 | 2.63 | Positive | Yes | 0.305 | 0.215 | 0.305 |
| Female, 74 y | 12 | Initially with headache, flu-like symptoms, limb pain, discomfort, petechia | 1 | 1.93 | Positive | Not known | 0.265 | 0.235 | 0.3 |
| Female, 55 y | 21 | Thrombosis of the V. ophthalmica, acute ischemic stroke, later focal seizures | 7 | 2.55 | Positive | No | 0.685 | 0.645 | 2.2 |
| Patient . | Platelet nadir (×109/L) . | Clinical symptoms . | Symptoms onset (no. of days after vaccination) . | Anti-PF4-heparin IgG ELISA (OD)* . | PF4-dependent platelet-activation assay (activated cells)† . | IvIgG prior blood withdrawal . | MAIPA‡ . | ||
|---|---|---|---|---|---|---|---|---|---|
| GPIIb/IIIa antibodies . | GPIb/IX antibodies . | GPIa/IIa antibodies . | |||||||
| Female, 40 y | 36 | Initially with severe headache and nausea, 5 d later CSVT | 6 | 2.94 | Positive | No | 0.145 | 0.12 | 1.915 |
| Female, 57 y | 24 | CSVT | 3 | 2.87 | Positive | No | 0.19 | 0.245 | 0.09 |
| Female, 61 y | 50 | Flu-like symptoms with headache and fever | 9 | 3.2 | Positive | Yes | 0.25 | 0.305 | 0.44 |
| Male, 20 y | 99 | Initially with headache, later pulmonary embolism and CSVT | Not known | 3.56 | Positive | Yes | 0.2 | 0.21 | 0.235 |
| Male, 21 y | 94 | Initially with headache, later CSVT | ∼2 | 3.12 | Positive | No | 0.18 | 0.265 | 0.34 |
| Female, 61 y | 46 | Initially with headache, later dissection of the A. vertebralis and infarct of the medulla oblongata. | 11 | 2.63 | Positive | Yes | 0.305 | 0.215 | 0.305 |
| Female, 74 y | 12 | Initially with headache, flu-like symptoms, limb pain, discomfort, petechia | 1 | 1.93 | Positive | Not known | 0.265 | 0.235 | 0.3 |
| Female, 55 y | 21 | Thrombosis of the V. ophthalmica, acute ischemic stroke, later focal seizures | 7 | 2.55 | Positive | No | 0.685 | 0.645 | 2.2 |
PF4–heparin enzyme-linked immunosorbent assay (ELISA) was done as described by Juhl et al.27 Reactivity on ELISA was defined according to the optical-density units (reference value OD < 0.50).
PF4-dependent platelet-activation assay was performed as recently described by Greinacher et al.49 The cutoff for a negative result is 0.50 optical-density units.
The cutoff for a negative result is OD < 0.2. Italic entries represent antiplatelet antibody detection.