Tools to support a clinical aTTP diagnosis
Plasmic and French scores can be used to predict ADAMTS13 deficiency1
Plasmic and French scores are based on laboratory parameters such as platelet count and creatinine level.2
Plasmic score
Plasmic Score1
|
Parameter |
Score | |
| Platelet count <30 × 109/L | +1 | |
| Serum creatinine level <2.0 mg/dL | +1 | |
| Evidence of hemolysis*: Indirect bilirubin >2.0 mg/dL or Reticulocyte count >2.5% or Undetectable haptoglobin |
+1 | |
| No active cancer in previous year* | +1 | |
| No history of solid organ or stem cell transplantation* | +1 | |
| INR <1.5* | +1 | |
| MCV <90 fL (<9.0 × 10-14/L)† | +1 | |
| Likelihood of severe ADAMTS13 deficiency‡ |
Low risk | 0 to 4: 0% to 4% |
| Intermediate risk | 5: 5% to 24% | |
| High risk | 6 to 7: 62% to 82% | |
|
Validation of the Plasmic score1 |
|||
| Derivation validation cohort (n=200) |
Internal validation cohort (n=150) |
External validation cohort (n=146) |
|
| 0-4 | 0/84 (0%) | 0/89 (0%) | 2/47 (4%) |
| 5 | 2/44 (5%) | 3/32 (9%) | 6/25 (24%) |
| 6-7 | 58/72 (81%) | 18/29 (62%) | 61/74 (82%) |
French score
French score1
| Parameter | Score |
| Platelet count <30 × 109/L | +1 |
| Serum creatinine level <2.25 mg/dL | +1 |
|
Prediction of severe ADAMTS13 deficiency |
0: 2% |
| 1: 70% | |
| 2: 94% |
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MAT-AE-2200643-V1-Nov-22