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PLASMIC Score for TTP

The PLASMIC score (0–7) estimates the probability of severe ADAMTS13 deficiency (TTP) in thrombotic microangiopathy. 0–4 is low risk (0–4%), 5 intermediate (5–24%) and 6–7 high risk (62–82%), favouring urgent plasma exchange pending ADAMTS13.

  • Platelet count (×10⁹/L or ×10³/µL)
  • Hemolysis (retic >2.5%, undetectable haptoglobin, or indirect bilirubin >2 mg/dL) (yes/no, +1)
  • Active cancer (treated within the past year) (yes/no, +1)
  • History of solid-organ or stem-cell transplant (yes/no, +1)
  • MCV (fL)
  • INR
  • Serum creatinine (mg/dL or µmol/L)
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Interpretation

ResultMeaning
0–4Low (0–4%)
5Intermediate (5–24%)
6–7High (62–82%)

Formula

1 point each: Platelets <30 ×10⁹/L · hemoLysis · no Active cancer · no Stem-cell/solid-organ transplant · MCV <90 fL · INR <1.5 · Creatinine <2.0 mg/dL

Clinical pearls

  • Send ADAMTS13 before plasma exchange; the score guides empiric therapy while results are pending.
  • Points for cancer and transplant are awarded when they are ABSENT.

Examples

plasmic plt 15 hemolysis yes no cancer no transplant mcv 85 inr 1.2 cr 1.1ttp probability platelets 80, haptoglobin undetectable, active cancer, mcv 95, inr 1.6, creatinine 2.5plasmic score for TMA with platelets 20 and schistocytes

FAQ

What PLASMIC score suggests TTP?

A score of 6–7 is high risk for severe ADAMTS13 deficiency; 5 is intermediate and 0–4 is low.

Does a low PLASMIC score rule out TTP?

It makes TTP unlikely (0–4% in the derivation cohorts), but clinical judgment and ADAMTS13 testing remain essential.

Evidence

  1. Bendapudi PK et al. Derivation and external validation of the PLASMIC score for rapid assessment of adults with thrombotic microangiopathies. Lancet Haematol 2017;4:e157–64.

Hematology & Oncology · Reviewed 2026-10-14 · Methodology