Validating lactate dehydrogenase (LDH) as a component of the PLASMIC predictive tool (PLASMIC-LDH)

Area of Science:

• Hematology
• Clinical Diagnostics
• Thrombotic Microangiopathies

Background:

• The PLASMIC score aids in predicting ADAMTS13 activity, crucial for diagnosing thrombotic thrombocytopenic purpura (TTP).
• Lactate dehydrogenase (LDH) is a common marker for hemolysis and may serve as a substitute for lysis markers in TTP monitoring.

Purpose of the Study:

• To validate the PLASMIC score's predictive capability for low ADAMTS13 activity in the Asia Pacific region.
• To investigate the utility of LDH as a replacement marker for lysis in TTP diagnosis and management.

Main Methods:

• Retrospective review of thrombotic microangiopathy (TMA) patient records, including ADAMTS13 activity and clinical data.
• Calculation of PLASMIC and PLASMIC-LDH scores (LDH replacing traditional lysis markers).
• Receiver operating characteristic (ROC) curve analysis to compare the predictive performance (AUC) of both scores.

Main Results:

• The PLASMIC score demonstrated high sensitivity (97.1%) and specificity (58.3%) for predicting low ADAMTS13 activity.
• The PLASMIC-LDH score also showed high sensitivity (97.1%) but lower specificity (33.3%) compared to the PLASMIC score.
• Positive predictive values were 86.8% for PLASMIC and 80.5% for PLASMIC-LDH; negative predictive values were 87.5% and 80.0%, respectively.

Conclusions:

• The study validates the PLASMIC score's utility in predicting low ADAMTS13 activity in the studied population.
• The PLASMIC-LDH score is a reasonable alternative for identifying high-risk patients when traditional lysis markers are absent.
• Both scores aid in identifying patients who may benefit from plasma exchange treatment.