Quantification of Thiopurine Nucleotides in Erythrocytes and Clinical Application to Pediatric Acute Lymphoblastic Leukemia

Soo Young Moon; Ji Hyun Lim; Eun Hee Kim; Youngwon Nam; Kyung Sang Yu; Kyung Taek Hong; Jung Yoon Choi; Che Ry Hong; Hyery Kim; Hyoung Jin Kang; Hee Young Shin; Kyunghoon Lee; Junghan Song; Soo Youn Lee; Sang Hoon Song

doi:10.1097/FTD.0000000000000575

Quantification of Thiopurine Nucleotides in Erythrocytes and Clinical Application to Pediatric Acute Lymphoblastic Leukemia

Soo Young Moon, Ji Hyun Lim, Eun Hee Kim, Youngwon Nam, Kyung Sang Yu, Kyung Taek Hong, Jung Yoon Choi, Che Ry Hong, Hyery Kim, Hyoung Jin Kang, Hee Young Shin, Kyunghoon Lee, Junghan Song, Soo Youn Lee, Sang Hoon Song

Research output: Contribution to journal › Article › peer-review

7 Scopus citations

Abstract

Background:Concentrations of 6-thioguanine (6TG) nucleotides and 6-methylmercaptopurine (6MMP) nucleotides in RBCs were measured using liquid chromatography-tandem mass spectrometry (LC-MS/MS). This assay was validated for clinical use and was applied to blood samples from patients taking mercaptopurine (6MP).Methods:RBCs were hemolyzed and deproteinized using perchloric acid, followed by heating for the hydrolysis of nucleotides, and the resultant base was measured using LC-MS/MS. Precision, recovery, linearity, matrix effect, and limit of quantification was validated for clinical application. Our results were compared with another institution's established LC-MS/MS assay. We measured the concentrations of 6TG and 6MMP in RBCs of pediatric patients with acute lymphoblastic leukemia (ALL), and the clinical impact of those metabolites was investigated.Results:The imprecision coefficient of variations of 6TG and 6MMP were 5.7%-8.1%, and the bias was within 5%. Lower limits of quantification were set at 54 ng/mL for 6TG and 1036 ng/mL for 6MMP. Correlation coefficients for 6TG and 6MMP were 0.997 and 1.0 in a comparison study. For clinical proof-of-concept, 74 blood samples were collected from 37 pediatric ALL patients receiving maintenance therapy. Concentration of 6TG ranged from 16.1 to 880 pmol/8 × 10⁸ RBCs and that of 6MMP from 55 to 20,937 pmol/8 × 10⁸ RBCs. The 6MP metabolites were not correlated with WBC or absolute neutrophil count. On the other hand, the higher 6MMP level was associated with elevated alanine aminotransferase and aspartate aminotransferase.Conclusions:In this study, an assay for the quantification of 6TG and 6MMP in RBCs was established and applied to pediatric ALL patients. Interindividual variability in 6MP metabolite concentrations was considerable and associated with elevation of liver enzymes, which may be useful in the clinical monitoring of 6MP maintenance therapy in pediatric ALL patients.

Original language	English
Pages (from-to)	75-85
Number of pages	11
Journal	Therapeutic Drug Monitoring
Volume	41
Issue number	1
DOIs	https://doi.org/10.1097/FTD.0000000000000575
State	Published - 1 Feb 2019

Bibliographical note

Publisher Copyright:
Copyright © 2018 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the International Association of Therapeutic Drug Monitoring and Clinical Toxicology.

Keywords

6-methylmercaptopurine (6MMP)
6-thioguanine (6TG)
LC-MS/MS
RBC
pediatric ALL

Access to Document

10.1097/FTD.0000000000000575

Cite this

Moon, S. Y., Lim, J. H., Kim, E. H., Nam, Y., Yu, K. S., Hong, K. T., Choi, J. Y., Hong, C. R., Kim, H., Kang, H. J., Shin, H. Y., Lee, K., Song, J., Lee, S. Y., & Song, S. H. (2019). Quantification of Thiopurine Nucleotides in Erythrocytes and Clinical Application to Pediatric Acute Lymphoblastic Leukemia. Therapeutic Drug Monitoring, 41(1), 75-85. https://doi.org/10.1097/FTD.0000000000000575

@article{14b66067b192439aa8c4b8e23722b6d7,

title = "Quantification of Thiopurine Nucleotides in Erythrocytes and Clinical Application to Pediatric Acute Lymphoblastic Leukemia",

abstract = "Background:Concentrations of 6-thioguanine (6TG) nucleotides and 6-methylmercaptopurine (6MMP) nucleotides in RBCs were measured using liquid chromatography-tandem mass spectrometry (LC-MS/MS). This assay was validated for clinical use and was applied to blood samples from patients taking mercaptopurine (6MP).Methods:RBCs were hemolyzed and deproteinized using perchloric acid, followed by heating for the hydrolysis of nucleotides, and the resultant base was measured using LC-MS/MS. Precision, recovery, linearity, matrix effect, and limit of quantification was validated for clinical application. Our results were compared with another institution's established LC-MS/MS assay. We measured the concentrations of 6TG and 6MMP in RBCs of pediatric patients with acute lymphoblastic leukemia (ALL), and the clinical impact of those metabolites was investigated.Results:The imprecision coefficient of variations of 6TG and 6MMP were 5.7%-8.1%, and the bias was within 5%. Lower limits of quantification were set at 54 ng/mL for 6TG and 1036 ng/mL for 6MMP. Correlation coefficients for 6TG and 6MMP were 0.997 and 1.0 in a comparison study. For clinical proof-of-concept, 74 blood samples were collected from 37 pediatric ALL patients receiving maintenance therapy. Concentration of 6TG ranged from 16.1 to 880 pmol/8 × 108 RBCs and that of 6MMP from 55 to 20,937 pmol/8 × 108 RBCs. The 6MP metabolites were not correlated with WBC or absolute neutrophil count. On the other hand, the higher 6MMP level was associated with elevated alanine aminotransferase and aspartate aminotransferase.Conclusions:In this study, an assay for the quantification of 6TG and 6MMP in RBCs was established and applied to pediatric ALL patients. Interindividual variability in 6MP metabolite concentrations was considerable and associated with elevation of liver enzymes, which may be useful in the clinical monitoring of 6MP maintenance therapy in pediatric ALL patients.",

keywords = "6-methylmercaptopurine (6MMP), 6-thioguanine (6TG), LC-MS/MS, RBC, pediatric ALL",

author = "Moon, {Soo Young} and Lim, {Ji Hyun} and Kim, {Eun Hee} and Youngwon Nam and Yu, {Kyung Sang} and Hong, {Kyung Taek} and Choi, {Jung Yoon} and Hong, {Che Ry} and Hyery Kim and Kang, {Hyoung Jin} and Shin, {Hee Young} and Kyunghoon Lee and Junghan Song and Lee, {Soo Youn} and Song, {Sang Hoon}",

note = "Publisher Copyright: Copyright {\textcopyright} 2018 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the International Association of Therapeutic Drug Monitoring and Clinical Toxicology.",

year = "2019",

month = feb,

day = "1",

doi = "10.1097/FTD.0000000000000575",

language = "English",

volume = "41",

pages = "75--85",

journal = "Therapeutic Drug Monitoring",

issn = "0163-4356",

publisher = "Lippincott Williams and Wilkins Ltd.",

number = "1",

}

Moon, SY, Lim, JH, Kim, EH, Nam, Y, Yu, KS , Hong, KT , Choi, JY, Hong, CR, Kim, H, Kang, HJ , Shin, HY , Lee, K , Song, J, Lee, SY & Song, SH 2019, 'Quantification of Thiopurine Nucleotides in Erythrocytes and Clinical Application to Pediatric Acute Lymphoblastic Leukemia', Therapeutic Drug Monitoring, vol. 41, no. 1, pp. 75-85. https://doi.org/10.1097/FTD.0000000000000575

TY - JOUR

T1 - Quantification of Thiopurine Nucleotides in Erythrocytes and Clinical Application to Pediatric Acute Lymphoblastic Leukemia

AU - Moon, Soo Young

AU - Lim, Ji Hyun

AU - Kim, Eun Hee

AU - Nam, Youngwon

AU - Yu, Kyung Sang

AU - Hong, Kyung Taek

AU - Choi, Jung Yoon

AU - Hong, Che Ry

AU - Kim, Hyery

AU - Kang, Hyoung Jin

AU - Shin, Hee Young

AU - Lee, Kyunghoon

AU - Song, Junghan

AU - Lee, Soo Youn

AU - Song, Sang Hoon

PY - 2019/2/1

Y1 - 2019/2/1

N2 - Background:Concentrations of 6-thioguanine (6TG) nucleotides and 6-methylmercaptopurine (6MMP) nucleotides in RBCs were measured using liquid chromatography-tandem mass spectrometry (LC-MS/MS). This assay was validated for clinical use and was applied to blood samples from patients taking mercaptopurine (6MP).Methods:RBCs were hemolyzed and deproteinized using perchloric acid, followed by heating for the hydrolysis of nucleotides, and the resultant base was measured using LC-MS/MS. Precision, recovery, linearity, matrix effect, and limit of quantification was validated for clinical application. Our results were compared with another institution's established LC-MS/MS assay. We measured the concentrations of 6TG and 6MMP in RBCs of pediatric patients with acute lymphoblastic leukemia (ALL), and the clinical impact of those metabolites was investigated.Results:The imprecision coefficient of variations of 6TG and 6MMP were 5.7%-8.1%, and the bias was within 5%. Lower limits of quantification were set at 54 ng/mL for 6TG and 1036 ng/mL for 6MMP. Correlation coefficients for 6TG and 6MMP were 0.997 and 1.0 in a comparison study. For clinical proof-of-concept, 74 blood samples were collected from 37 pediatric ALL patients receiving maintenance therapy. Concentration of 6TG ranged from 16.1 to 880 pmol/8 × 108 RBCs and that of 6MMP from 55 to 20,937 pmol/8 × 108 RBCs. The 6MP metabolites were not correlated with WBC or absolute neutrophil count. On the other hand, the higher 6MMP level was associated with elevated alanine aminotransferase and aspartate aminotransferase.Conclusions:In this study, an assay for the quantification of 6TG and 6MMP in RBCs was established and applied to pediatric ALL patients. Interindividual variability in 6MP metabolite concentrations was considerable and associated with elevation of liver enzymes, which may be useful in the clinical monitoring of 6MP maintenance therapy in pediatric ALL patients.

AB - Background:Concentrations of 6-thioguanine (6TG) nucleotides and 6-methylmercaptopurine (6MMP) nucleotides in RBCs were measured using liquid chromatography-tandem mass spectrometry (LC-MS/MS). This assay was validated for clinical use and was applied to blood samples from patients taking mercaptopurine (6MP).Methods:RBCs were hemolyzed and deproteinized using perchloric acid, followed by heating for the hydrolysis of nucleotides, and the resultant base was measured using LC-MS/MS. Precision, recovery, linearity, matrix effect, and limit of quantification was validated for clinical application. Our results were compared with another institution's established LC-MS/MS assay. We measured the concentrations of 6TG and 6MMP in RBCs of pediatric patients with acute lymphoblastic leukemia (ALL), and the clinical impact of those metabolites was investigated.Results:The imprecision coefficient of variations of 6TG and 6MMP were 5.7%-8.1%, and the bias was within 5%. Lower limits of quantification were set at 54 ng/mL for 6TG and 1036 ng/mL for 6MMP. Correlation coefficients for 6TG and 6MMP were 0.997 and 1.0 in a comparison study. For clinical proof-of-concept, 74 blood samples were collected from 37 pediatric ALL patients receiving maintenance therapy. Concentration of 6TG ranged from 16.1 to 880 pmol/8 × 108 RBCs and that of 6MMP from 55 to 20,937 pmol/8 × 108 RBCs. The 6MP metabolites were not correlated with WBC or absolute neutrophil count. On the other hand, the higher 6MMP level was associated with elevated alanine aminotransferase and aspartate aminotransferase.Conclusions:In this study, an assay for the quantification of 6TG and 6MMP in RBCs was established and applied to pediatric ALL patients. Interindividual variability in 6MP metabolite concentrations was considerable and associated with elevation of liver enzymes, which may be useful in the clinical monitoring of 6MP maintenance therapy in pediatric ALL patients.

KW - 6-methylmercaptopurine (6MMP)

KW - 6-thioguanine (6TG)

KW - LC-MS/MS

KW - RBC

KW - pediatric ALL

UR - http://www.scopus.com/inward/record.url?scp=85059829231&partnerID=8YFLogxK

U2 - 10.1097/FTD.0000000000000575

DO - 10.1097/FTD.0000000000000575

M3 - Article

C2 - 30507626

AN - SCOPUS:85059829231

SN - 0163-4356

VL - 41

SP - 75

EP - 85

JO - Therapeutic Drug Monitoring

JF - Therapeutic Drug Monitoring

IS - 1

ER -

Quantification of Thiopurine Nucleotides in Erythrocytes and Clinical Application to Pediatric Acute Lymphoblastic Leukemia

Abstract

Bibliographical note

Keywords

Access to Document

Other files and links

Fingerprint

Cite this