Table 1. Details of SARS-CoV-2 Vaccination, Previous COVID-19 Infection, and Thrombocytopenia.
| Variable | Group, No./total No. (%) | |
|---|---|---|
| TTS (n = 78) | No TTS (n = 38) | |
| SARS-CoV-2 vaccinea | ||
| ChAdOx1 nCov-19 | 76/78 (97)b | 20/38 (53) |
| Ad26.COV2.S | 1/78 (1) | 0 |
| BNT162b2 | 1/78 (1) | 15/38 (40)c |
| mRNA-1273 | 0 | 1/38 (3) |
| CoronaVac | 0 | 2/38 (5) |
| Time from vaccination to CVST symptom onset, median (IQR), dd | 9 (7-10) | 7 (3-16) |
| Previous COVID-19 infection | 1/72 (1) | 4/36 (11) |
| Confirmede | 0 | 4/36 (11) |
| Suspected | 1/72 (1) | 0 |
| Thrombocytopenia details | ||
| Platelet count at admission, median (IQR), ×103/μL | 45 (25-71) | 272 (224-319) |
| Platelet count nadir, median (IQR), ×103/μL | 30 (14-53)f | NA |
| Positive for PF4 antibodies | 63/69 (91)g | NA |
| Positive findings on platelet activation assays | 36/36 (100) | NA |
| Positive for antiphospholipid antibodies | 8/56 (14)h | 0i |
Abbreviations: CVST, cerebral venous sinus thrombosis; NA, not applicable; TTS, thrombosis with thrombocytopenia syndrome.
SI conversion factor: To convert platelet count to ×109 per liter, multiply by 1.
In the ChAdOx1 nCov-19 group, 29 different vaccine batch numbers could be identified among 53 patients; in the BNT162b2 group, 9 different batch numbers among 10 patients; and in the CoronaVac group, 1 batch number in 1 patient.
One patient developed CVST with TTS after the second ChAdOx1 nCov-19 vaccination; PF4 antibodies were not tested in this patient.
Nine patients developed CVST without TTS after the second BNT162b2 vaccination.
Data for 1 patient was missing in each group.
Positive findings on nucleic acid amplification test.
Data missing for 11 patients.
Of the 6 patients who tested negative for PF4 antibodies, 3 were tested with an enzyme-linked immunosorbent assay and 3 with a rapid test.
Not performed in 22 patients.
Not performed in 9 patients.