Plasmic Score for TTP

Predicts ADAMTS13 deficiency in suspected thrombotic thrombocytopenic purpura (TTP) with high discrimination.

The global unit selector only affects unanswered questions
1.Platelet count < 30 x 10⁹/L?
3.Active cancer (or treated for active cancer in last year)?
4.History of solid organ or stem-cell transplant?
5.MCV < 90 fL (9.0 x 10⁻¹⁴/L)?
6.INR < 1.5?
7.Creatinine < 2.0 mg/dL / 176.8 umol/L?
Created by

1. Platelet count < 30 x 10⁹/L?

Created by
0/7 completed

About this Calculator

The PLASMIC Score was derived by Bendapudi et al and externally validated in a study with an independent cohort of 112 consecutive hospitalized patients with suspected thrombotic microangiopathy and appropriate ADAMTS-13 testing (including 21 patients with TTP diagnosis). The PLASMIC model predicted severe ADAMTS-13 deficiency with a c statistic of 0.94 (0.88-0.98). When dichotomized at high (scores 6-7) vs. low-intermediate risk (scores 0-5), the model predicted severe ADAMTS-13 deficiency with positive predictive value 72%, negative predictive value 98%, sensitivity 90% and specificity 92%.

In the low-intermediate risk group (scores 0-5), there was no significant improvement in overall survival associated with plasma exchange. The PLASMIC Score had excellent applicability, discrimination and calibration for predicting severe ADAMTS-13 deficiency. The clinical algorithm allowed identification of a subgroup of patients who lacked a significant response to empiric treatment.


Li A, Khalighi PR, Wu Q, Garcia DA.

External validation of the PLASMIC score: a clinical prediction tool for thrombotic thrombocytopenic purpura diagnosis and treatment.

Journal of Thrombosis and Haemostasis: JTH 2018, 16 (1): 164-169.

Contributed By:
  • Matthew Federbush, MD
Legal Notices and Disclaimer

© 2020 QxMD Software Inc., all rights reserved. No part of this service may be reproduced in any way without express written consent of QxMD. This information should not be used for the diagnosis or treatment of any health problem or disease. This information is not intended to replace clinical judgment or guide individual patient care in any manner. Click here for full notice and disclaimer.