Synthesis and evaluation of a 18F-labelled recombinant annexin-V derivative, for identification and quantification of apoptotic cells with PET.

In this report, we describe the synthesis of 4-[18F]-fluorobenzoyl-annexin V (4-[18F]FBA). In a four-step procedure, 4-[18F]FBA was synthesised with a microcomputer controlled, automated module within 90min. The radiochemical yield was in the range of 15-20% (corrected for decay) with a specific activity of more than 35GBq/micromol. The specific binding was confirmed by studies of 4-[18F]FBA with phosphatidylserine-containing liposomes. The biological activity of 4-[18F]FBA was verified by measuring its binding to Jurkat T-cell lymphoblasts after induction of apoptosis as compared to control cells without apoptosis. 4-[18F]FBA seems to be a suited tracer to measure apoptotic activity in vivo.