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 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 score1

    Parameter

    Score

    Platelet count <30 × 109/L

    +1

    Serum creatinine level <2.25 mg/dL

    +1

     

     

    Prediction of severe ADAMTS13 deficiency
    (activity <10%) based on score‡

    0: 2%

     

    1: 70%

     

    2: 94%

MAT-AE-2200643-V2-OCT-23