Novel Fluorometric Assay for Pediatric Anti-Factor Xa Testing: Minimizing Bilirubin and Hemolysis Interference in Whole Blood

High bilirubin levels, commonly observed in pediatric patients and those undergoing extracorporeal membrane oxygenation (ECMO), can interfere with chromogenic assays for anti-Factor Xa (aFXa) activity. Other known interferents for aFXa assays include hemoglobin, platelet activation, and platelet factor 4 (PF4). While frequent monitoring of aFXa activity is crucial for managing acute anticoagulation therapy, particularly in pediatric and neonatal patients, repeated blood draws may lead to iatrogenic anemia, presenting a significant challenge for these vulnerable populations.

In this poster presented at ADLM 24, we showcase a point-of-care digital microfluidic (DMF) platform that is under development for a fluorescence-based aFXa activity assay. This assay requires low-volume whole blood samples (<50 μL) and integrates plasma separation.

Key findings include:

• Our interference studies show that the aFXa assay is highly tolerant to elevated bilirubin and hemolysate levels.
• Plasma separation in the cartridge produces results equivalent to platelet-poor plasma, as confirmed by PF4 levels and platelet counts.

Ongoing clinical studies are focused on validating the clinical performance of this point-of-care aFXa assay.

Explore the complete poster to learn more.