Characteristics of individuals included in the study
| Characteristics . | Vax controls . | VITT ELISA positive . | VITT ELISA negative . | VTE no VITT . | P value . |
|---|---|---|---|---|---|
| Number of patients | 17 | 21 | 19 | 12 | NA |
| Male/female | 9/8 | 11/10 | 12/7 | 9/4 | .805 |
| Age (range), y | 55 (33-71) | 63 (50-76) | 66 (56-81) | 75 (60-81) | .102 |
| Days from vaccination (range) | 7 (4-14) | 12 (8-15) | 10 (4-16) | 13 (8-22) | .063 |
| Platelet level at presentation, median (range), ×106/L | 250 (243-291) | 54 (32-117) | 115 (89-125) | 217 (201-324) | <.0001 |
| D-dimers at presentation × fold of upper limit of normal (range) | NA | 40 (18-40) | 17 (7-40) | 3.6 (2-21) | .047 |
| CVST | NA | 6 | 7 | 6 | .485 |
| Splanchnic vein thrombosis | NA | 2 | 2 | 1 | .980 |
| PE/DVT | NA | 11 | 9 | 4 | .522 |
| Arterial thrombosis | NA | 2 | 1 | 1 | .882 |
| ELISA OD | 0.08 (0.06-0.10) | 2.19 (0.72-2.79) | 0.11 (0.07-0.15) | 0.07 (0.06-0.13) | <.0001 |
| Patients with positive platelet functional assay/number of patients tested per group | 1/8 | 20/21 | 8/17 | 1/10 | <.0001 |
| Characteristics . | Vax controls . | VITT ELISA positive . | VITT ELISA negative . | VTE no VITT . | P value . |
|---|---|---|---|---|---|
| Number of patients | 17 | 21 | 19 | 12 | NA |
| Male/female | 9/8 | 11/10 | 12/7 | 9/4 | .805 |
| Age (range), y | 55 (33-71) | 63 (50-76) | 66 (56-81) | 75 (60-81) | .102 |
| Days from vaccination (range) | 7 (4-14) | 12 (8-15) | 10 (4-16) | 13 (8-22) | .063 |
| Platelet level at presentation, median (range), ×106/L | 250 (243-291) | 54 (32-117) | 115 (89-125) | 217 (201-324) | <.0001 |
| D-dimers at presentation × fold of upper limit of normal (range) | NA | 40 (18-40) | 17 (7-40) | 3.6 (2-21) | .047 |
| CVST | NA | 6 | 7 | 6 | .485 |
| Splanchnic vein thrombosis | NA | 2 | 2 | 1 | .980 |
| PE/DVT | NA | 11 | 9 | 4 | .522 |
| Arterial thrombosis | NA | 2 | 1 | 1 | .882 |
| ELISA OD | 0.08 (0.06-0.10) | 2.19 (0.72-2.79) | 0.11 (0.07-0.15) | 0.07 (0.06-0.13) | <.0001 |
| Patients with positive platelet functional assay/number of patients tested per group | 1/8 | 20/21 | 8/17 | 1/10 | <.0001 |
Values are given as median (25%-75% interquartile range). Functional assay positivity was defined as patient sample testing positive by at least 1 platelet functional VITT test, including procoagulant platelets by flow cytometry,12,14 serotonin release assay,12 or Multiplate.13 Comparison of groups was by 1-way analysis of variance with Dunn post hoc test.
CVST, cerebral vein sinus thrombosis; DVT, deep vein thrombosis; NA, not applicable; OD, optical density; PE, pulmonary embolism.