[Automated kinetic assay of plasmatic L-asparaginase activity undergoing therapy for acute lymphoblastic leukemia]

The L-asparaginase is a critical drug for the treatment of acute lymphoblastic leukaemia, that achieves blood L-asparagin depletion. However, such a therapy is associated with a high rate of negative side effects, particularly antibody synthesis against L-asparaginase. This therefore decreases therapy efficiency requiring the monitoring of L-asparaginase activity since L-asparagin determination is not easy. We compared here the results obtained with an automated kinetic enzymatic method to those obtained with the most commonly used Nessler reagent method. The correlation coefficient, r = 0,992, obtained was very good, and the allometric regression line was y = 1,038x - 0,37 microkat/L. We also showed that the specificity and the precision were better with the enzymatic method than the Nessler one. Moreover, the enzymatic method was easier and required less time to perform. Finally, the method appears able to perform real time monitoring of the therapy.