ToolsCalculators
PLASMIC Score for TTP
Predicts severe ADAMTS13 deficiency in thrombotic microangiopathy.
PLASMIC Score for TTP
Platelet count <30 x10^9/L
Haemolysis (reticulocytes >2.5%, undetectable haptoglobin, or indirect bilirubin >2 mg/dL)
No active cancer in past year
No history of solid-organ or stem-cell transplant
MCV <90 fL
INR <1.5
Creatinine <2.0 mg/dL
Result0 points
Low probability of severe ADAMTS13 deficiency (about 0-4%).
- PLASMIC score (0-7)
- 0
- Risk of ADAMTS13 <10%
- 0-4%
When to use
- Estimating the likelihood of severe ADAMTS13 deficiency (TTP) in a patient with thrombotic microangiopathy before enzyme results return.
Formula
One point each for: platelets <30, haemolysis, no active cancer, no prior transplant, MCV <90 fL, INR <1.5, creatinine <2.0 mg/dL. Score 6-7 = high risk of severe ADAMTS13 deficiency.
Pearls and pitfalls
- A high score (6-7) supports empirical plasma exchange while awaiting confirmatory ADAMTS13 testing.