A High-Throughput Blood Esterase Panel Assay

Organophosphorus chemical warfare nerve agents (OP-CWA) are attractive to terrorist groups and rogue states as an inexpensive and accessible technology for chemical warfare. OP-CWA and organophosphate pesticides cause severe neurological symptoms and death by inhibiting the enzyme acetylcholinesterase (AChE); the resulting excess acetylcholine accumulates and overstimulates the human or animal body. Other esterases and organophosphatases in the blood either bind (butyrylcholinesterase, BChE) or catalytically degrade (paraoxonase, PON1) OP-CWA. Therefore, it is critically important to be able to quickly monitor the human blood complement of OP-CWA enzymes to assess both susceptibility and current condition. For military and civilian clinical use, a high-throughput, minimally invasive assay system is needed to quickly and accurately screen large numbers of soldiers/agricultural workers/first responders for OP-CWA or OP-pesticide exposure. The currently available WRAIR assay is high-throughput, uses a minimal amount of whole blood, and is sensitive and accurate for AChE and BChE levels. An assay that additionally measures PON1 and albumin esterase activities relevant to OP degradation and/or binding is greatly needed to more fully assess OP-CWA or -pesticide susceptibility for individuals at risk.