Plasmic Score for TTP
Predict ADAMTS13 deficiency in suspected thrombotic thrombocytopenic purpura (TTP) with high discrimination.
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.
Bendapudi PK, Hurwitz S, Fry A et al.
Li A, Khalighi PR, Wu Q, Garcia DA.