Patient characteristics with thrombosis and thrombocytopenia following ChAdOx1 nCoV-19 vaccination
| Patient . | 1 . | 2 . | 3 . | 4 . | 5 . | 6 . | 7 . |
|---|---|---|---|---|---|---|---|
| Age (yrs) | 47 | 37 | 53 | 38 | 56 | 61 | 64 |
| Sex | Female | Male | Male | Male | Male | Male | Male |
| Vaccine type | ChAdOx1 nCoV-19 (dose 1) | ChAdOx1 nCoV-19 (dose 1) | ChAdOx1 nCoV-19 (dose 1) | ChAdOx1 nCoV-19 (dose 1) | ChAdOx1 nCoV-19 (dose 1) | ChAdOx1 nCoV-19 (dose 1) | ChAdOx1 nCoV-19 (dose 2) |
| Onset of symptoms after vaccination (d) | 5 | 10 | 6 | No symptoms* | 6 | 33 | 9 |
| Initial presentation after vaccination (d) | 11 | 17 | 12 | 19 | 20 | 36 | 13 |
| Laboratory parameters at presentation | |||||||
| Platelets (per mm3) | 35 000 | 83 000 | 52 000 | 88 000 | 149 000 | 129 000 | 93 000 |
| d-dimer (mg/L FEU) | 37.19 | 39.00 | 19.38 | 1.105 | 34.80 | 18.39 | 4.12 |
| PF4-ELISA (OD) | Positive (2.58) | Positive (2.56) | Positive (2.75) | Positive (1.98) | Negative (0.08) | Negative (0.12) | Negative (0.07) |
| SRA | Positive | Positive | Positive | Positive | Negative | Negative | Negative |
| Thrombotic complications | PE; DVT | SMV thrombus; PVT; SpVT; PE | PVT | None† | PE; DVT | PE; DVT; SMA thrombus | Lacunar infract |
| Treatments received‡ | IVIG; prednisone; argatroban; rivaroxaban | IVIG; argatroban; fondaparinux; small bowel resection | IVIG; dexamethason; apixaban | Rivaroxaban | Catheter-directed thrombolysis of PE; unfractionated heparin; argatroban; apixaban | IVIG; SMA thrombo-endarterectom; argatroban; unfractionated heparin; warfarin | IVIG; apixaban |
| Outcomes | Platelets normal d 29; SRA negative at d 174; PF4-ELISA positive at d 239 (OD 1.06) | Platelets normal d 202; SRA positive at d 202; PF4-ELISA positive at d 202 (OD 2.06) | Platelets normal d 16; PF4-ELISA positive d 96 (OD 1.38) | Platelets normal d 69; SRA negative d 182; PF4-ELISA positive d 182 (OD 0.65) | Platelets normal d 24 | Platelets normal d 41 | Platelets normal d 37 |
| Patient . | 1 . | 2 . | 3 . | 4 . | 5 . | 6 . | 7 . |
|---|---|---|---|---|---|---|---|
| Age (yrs) | 47 | 37 | 53 | 38 | 56 | 61 | 64 |
| Sex | Female | Male | Male | Male | Male | Male | Male |
| Vaccine type | ChAdOx1 nCoV-19 (dose 1) | ChAdOx1 nCoV-19 (dose 1) | ChAdOx1 nCoV-19 (dose 1) | ChAdOx1 nCoV-19 (dose 1) | ChAdOx1 nCoV-19 (dose 1) | ChAdOx1 nCoV-19 (dose 1) | ChAdOx1 nCoV-19 (dose 2) |
| Onset of symptoms after vaccination (d) | 5 | 10 | 6 | No symptoms* | 6 | 33 | 9 |
| Initial presentation after vaccination (d) | 11 | 17 | 12 | 19 | 20 | 36 | 13 |
| Laboratory parameters at presentation | |||||||
| Platelets (per mm3) | 35 000 | 83 000 | 52 000 | 88 000 | 149 000 | 129 000 | 93 000 |
| d-dimer (mg/L FEU) | 37.19 | 39.00 | 19.38 | 1.105 | 34.80 | 18.39 | 4.12 |
| PF4-ELISA (OD) | Positive (2.58) | Positive (2.56) | Positive (2.75) | Positive (1.98) | Negative (0.08) | Negative (0.12) | Negative (0.07) |
| SRA | Positive | Positive | Positive | Positive | Negative | Negative | Negative |
| Thrombotic complications | PE; DVT | SMV thrombus; PVT; SpVT; PE | PVT | None† | PE; DVT | PE; DVT; SMA thrombus | Lacunar infract |
| Treatments received‡ | IVIG; prednisone; argatroban; rivaroxaban | IVIG; argatroban; fondaparinux; small bowel resection | IVIG; dexamethason; apixaban | Rivaroxaban | Catheter-directed thrombolysis of PE; unfractionated heparin; argatroban; apixaban | IVIG; SMA thrombo-endarterectom; argatroban; unfractionated heparin; warfarin | IVIG; apixaban |
| Outcomes | Platelets normal d 29; SRA negative at d 174; PF4-ELISA positive at d 239 (OD 1.06) | Platelets normal d 202; SRA positive at d 202; PF4-ELISA positive at d 202 (OD 2.06) | Platelets normal d 16; PF4-ELISA positive d 96 (OD 1.38) | Platelets normal d 69; SRA negative d 182; PF4-ELISA positive d 182 (OD 0.65) | Platelets normal d 24 | Platelets normal d 41 | Platelets normal d 37 |
Low platelets noted on routine bloodwork, no clinical symptoms present.
No thrombotic complications noted despite extensive imagine (CT head with venogram, CT chest, Doppler ultrasound both legs).
Treatment received for patients with positive PF4-ELISA. Patient 1: 3 doses of IVIG 1 g/kg and a short course of prednisone (initial dose of 1 g/kg followed by a taper). Initial anticoagulation with argatroban and then transitioned to rivaroxaban at 15 mg twice daily for 3 weeks, followed by 20 mg once daily. Patient 2: 4 doses of IVIG 1 g/kg and prolonged course of prednisone (initial dose 1 g/kg followed by a taper). Patient 2 received a short course of argatroban followed by extended anticoagulation with fondaparinux because of a high output ileostomy. Patient 3: 2 doses of IVIG 1 g/kg and dexamethasone pulse at 40 mg once daily for 4 days. Anticoagulation with apixaban at 10 mg twice daily for 6 weeks while the d-dimer level was still elevated (per physician-patient preference), then stepped down to 5 mg twice daily. Apixaban was discontinued after completing 3.5 months of treatment. Patient 4: 15 mg of rivaroxaban twice daily for 3 weeks, followed by 20 mg daily. A further step down to 10 mg daily at day 155 given persistently positive PF4-ELISA.
CT, computed tomography; DVT, deep vein thrombosis; OD, optical density; PE, pulmonary embolism; PVT, portal vein thrombosis; SMA, superior mesenteric artery; SMV, superior mesenteric vein; SpVT, splenic vein thrombus.