PLASMIC score for thrombotic thrombocytopenic purpura

The PLASMIC score uses seven routine findings to estimate the probability of severe ADAMTS13 deficiency in patients with thrombotic microangiopathy, before the ADAMTS13 result returns.

What goes into the PLASMIC score

Platelets < 30,000/µL (+1)
Hemolysis (reticulocytes > 2.5%, undetectable haptoglobin, or indirect bilirubin > 2 mg/dL) (+1)
No active cancer in the past year (+1)
No solid-organ or stem-cell transplant (+1)
MCV < 90 fL (+1)
INR < 1.5 (+1)
Creatinine < 2.0 mg/dL (+1)

How to interpret the result

0–4: low probability (0–4%)
5: intermediate probability (about 5–24%)
6–7: high probability (about 62–82%); start plasma exchange

Clinical pearls

Always send ADAMTS13 activity before plasma exchange or plasma.
Avoid platelet transfusion in suspected TTP unless there is life-threatening bleeding.
Caplacizumab is added to plasma exchange and immunosuppression for immune TTP.

Evidence

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-e164.

Related workups

Thrombocytopenia (including TTP, HIT and ITP)Anemia in hospitalized adults Acute kidney injury

Related calculators

4Ts score Anion gap and delta ratio All calculators

For education only. Check the inputs and the population the score was validated in before acting on it. Not a substitute for clinical judgment.