TY - JOUR
T1 - Improved HPLC Quantification of 6-Mercaptopurine Metabolites in Red Blood Cells
T2 - Monitoring Data and Literature Analysis
AU - Adam de Beaumais, Tiphaine
AU - Medard, Yves
AU - Amblard, Océane
AU - Goldwirt, Lauriane
AU - Simonin, Mathieu
AU - Martinez Vinson, Christine
AU - Petit, Arnaud
AU - Jacqz-Aigrain, Evelyne
N1 - Publisher Copyright:
© 2022 by the authors.
PY - 2022/10/1
Y1 - 2022/10/1
N2 - Thiopurine drugs azathioprine (AZA) and 6-mercaptopurine (6-MP) are used extensively in pediatric and adult patients with inflammatory and neoplastic diseases. They are metabolized to 6-thioguanine nucleotides (6-TGN) or to 6-methyl-mercaptopurine nucleotides (6-MMPN). The balance between 6-TGN and 6-MMPN is highly variable and monitoring is recommended, but its benefit in outcome gives rise to conflicting results, potentially increased by differences in quantifying 6-MP metabolism. Our aim was to report (1) the HPLC-UV procedure used in our laboratory to quantify red blood cells (RBCs) with 6-TGN and 6-MMPN (as its derivate: 6-MMP(d)) in patients treated with thiopurines and (2) additional tests, sometimes confirmatory, to improve method standardization. The comparison of two methods to count RBCs shows that metabolite concentrations were slightly lower in the washed and resuspended RBCs than in whole blood. Perchloric acid (0.7 M), dithiothreitol (DTT, final 0.013 M sample concentration) and 60 min hydrolysis were selected for acid hydrolysis. (3) Monitoring data from 83 patients receiving AZA or 6-MP showed that at steady state, only 53/183 (29%) had 6-TGN and 6-MMPN in the recommended therapeutic range. Our method is discussed in light of the technical conditions and sample stability data from 17 publications identified since the first analytical report in 1987. Monitoring data demonstrate, if required, that inter-patient variability in 6-TGN and 6-MMPN concentrations is high in samples from treated patients.
AB - Thiopurine drugs azathioprine (AZA) and 6-mercaptopurine (6-MP) are used extensively in pediatric and adult patients with inflammatory and neoplastic diseases. They are metabolized to 6-thioguanine nucleotides (6-TGN) or to 6-methyl-mercaptopurine nucleotides (6-MMPN). The balance between 6-TGN and 6-MMPN is highly variable and monitoring is recommended, but its benefit in outcome gives rise to conflicting results, potentially increased by differences in quantifying 6-MP metabolism. Our aim was to report (1) the HPLC-UV procedure used in our laboratory to quantify red blood cells (RBCs) with 6-TGN and 6-MMPN (as its derivate: 6-MMP(d)) in patients treated with thiopurines and (2) additional tests, sometimes confirmatory, to improve method standardization. The comparison of two methods to count RBCs shows that metabolite concentrations were slightly lower in the washed and resuspended RBCs than in whole blood. Perchloric acid (0.7 M), dithiothreitol (DTT, final 0.013 M sample concentration) and 60 min hydrolysis were selected for acid hydrolysis. (3) Monitoring data from 83 patients receiving AZA or 6-MP showed that at steady state, only 53/183 (29%) had 6-TGN and 6-MMPN in the recommended therapeutic range. Our method is discussed in light of the technical conditions and sample stability data from 17 publications identified since the first analytical report in 1987. Monitoring data demonstrate, if required, that inter-patient variability in 6-TGN and 6-MMPN concentrations is high in samples from treated patients.
KW - 6-mercaptopurine
KW - 6-thiopurines
KW - acute leukemia
KW - chronic inflammatory bowel disease
KW - monitoring
KW - pharmacogenetics
KW - thiopurines
UR - http://www.scopus.com/inward/record.url?scp=85139833078&partnerID=8YFLogxK
U2 - 10.3390/ijms231911885
DO - 10.3390/ijms231911885
M3 - Article
C2 - 36233187
AN - SCOPUS:85139833078
SN - 1661-6596
VL - 23
JO - International Journal of Molecular Sciences
JF - International Journal of Molecular Sciences
IS - 19
M1 - 11885
ER -