Determination of L-asparagine in biological samples in the presence of L-asparaginase.
The antileukaemic efficacy of L-asparaginase is related to the ability of the enzyme to induce the complete disappearance from plasma of L-asparagine, an amino acid essential to lymphoblastic leukaemia cells. It is not feasible to monitor L-asparagine plasma levels in patients under L-asparaginase treatment using the usual analytical procedures as the enzyme continues the hydrolysis of L-asparagine after blood sampling and during plasma extraction. A method was therefore developed for the determination of L-asparagine in patients receiving L-asparaginase. Sulphosalicylic acid is added to blood samples to deproteinize and inactivate L-asparaginase rapidly. The samples are then analysed by HPLC using a Novapack C18 column and fluorescence detection. With the same method L-asparagine is determined in blood cells and, by difference, plasma levels are calculated. This method is highly specific and sufficiently simple and sensitive for clinical use.
Gentili
D
D
Mario Negri Institute, Milan, Italy.
Zucchetti
M
M
Conter
V
V
Masera
G
G
D'Incalci
M
M
D001215:Asparaginase / Q000037:antagonists & inhibitors / Q000627:therapeutic use*; D001216:Asparagine / Q000097:blood*; D001557:Benzenesulfonates; D002851:Chromatography, High Pressure Liquid / Q000379:methods / Q000706:statistics & numerical data; D004355:Drug Stability; D004885:Erwinia / Q000201:enzymology; D004912:Erythrocytes / Q000737:chemistry; D005615:Freezing; D006801:Humans; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000097:blood* / Q000188:drug therapy; D011786:Quality Control; D012459:Salicylates / Q000494:pharmacology; D012680:Sensitivity and Specificity
D001557:Benzenesulfonates; D012459:Salicylates; D001216:Asparagine; D001215:Asparaginase; C003366:sulfosalicylic acid