PURPOSE: The objectives of this study were (1) to develop a population pharmacokinetic model of high-dose methotrexate (HD-MTX) in children with acute lymphoblastic leukaemia (ALL) and malignant lymphoma (ML) in order to investigate the influence of common polymorphisms in SLC19A1, MTHFR and ABCB1 on plasma levels of MTX and (2) to estimate MTX exposure in individual patients to study the association of genetic variability in the folate metabolic pathway with MTX toxicity. METHODS: The study population comprised 64 children with ALL/ML (age 1.6-16.8 years) who had received a total of 252 MTX courses (2-4 per patient). Common putative functional polymorphisms in the SLC19A1, MTHFR, MS, MTRR, TS and ABCB1 genes were analysed by PCR-based genotyping. Nonlinear mixed effects modelling was used for the pharmacokinetic analysis. RESULTS: The population typical value of clearance was 7.43 L/h (inter-individual variability 43.9%), central compartment volume was 16.7 L (46.6%), peripheral compartment volume was 2.6 L (63.3%) and distribution clearance was 0.0952 L/h (66.6%). MTX clearance decreased to 73.8% in patients with the MTHFR 677TT genotype. Patients homozygous for the variant MTHFR 1298A > C [odds ratio (OR) 0.14, 95% confidence interval (CI) 0.037-0.54] and SLC19A1 80A > G (OR 0.15, 95% CI 0.039-0.60) were at decreased risk for leucopenia. The TS 2R > 3R polymorphism was associated with a lower incidence of thrombocytopenia (OR 0.15, 95% CI 0.039-0.61) and mucositis (OR 0.016, 95% CI 0.0012-0.20). In contrast, the MTHFR 677TT polymorphism was associated with an increased incidence of mucositis (OR 23, 95% CI 2.1-240). CONCLUSIONS: A population pharmacokinetic model developed in this study implies only a limited influence of genetic factors on the systemic disposition of MTX. Clearance is moderately reduced in patients with the MTHFR 677TT genotype. Genetic polymorphisms in the folate metabolic pathway and SLC19A1 were associated with HD-MTX toxicity.
PURPOSE: The objectives of this study were (1) to develop a population pharmacokinetic model of high-dose methotrexate (HD-MTX) in children with acute lymphoblastic leukaemia (ALL) and malignant lymphoma (ML) in order to investigate the influence of common polymorphisms in SLC19A1, MTHFR and ABCB1 on plasma levels of MTX and (2) to estimate MTX exposure in individual patients to study the association of genetic variability in the folate metabolic pathway with MTXtoxicity. METHODS: The study population comprised 64 children with ALL/ML (age 1.6-16.8 years) who had received a total of 252 MTX courses (2-4 per patient). Common putative functional polymorphisms in the SLC19A1, MTHFR, MS, MTRR, TS and ABCB1 genes were analysed by PCR-based genotyping. Nonlinear mixed effects modelling was used for the pharmacokinetic analysis. RESULTS: The population typical value of clearance was 7.43 L/h (inter-individual variability 43.9%), central compartment volume was 16.7 L (46.6%), peripheral compartment volume was 2.6 L (63.3%) and distribution clearance was 0.0952 L/h (66.6%). MTX clearance decreased to 73.8% in patients with the MTHFR 677TT genotype. Patients homozygous for the variant MTHFR 1298A > C [odds ratio (OR) 0.14, 95% confidence interval (CI) 0.037-0.54] and SLC19A1 80A > G (OR 0.15, 95% CI 0.039-0.60) were at decreased risk for leucopenia. The TS 2R > 3R polymorphism was associated with a lower incidence of thrombocytopenia (OR 0.15, 95% CI 0.039-0.61) and mucositis (OR 0.016, 95% CI 0.0012-0.20). In contrast, the MTHFR 677TT polymorphism was associated with an increased incidence of mucositis (OR 23, 95% CI 2.1-240). CONCLUSIONS: A population pharmacokinetic model developed in this study implies only a limited influence of genetic factors on the systemic disposition of MTX. Clearance is moderately reduced in patients with the MTHFR 677TT genotype. Genetic polymorphisms in the folate metabolic pathway and SLC19A1 were associated with HD-MTX toxicity.
Authors: R Takatori; K A Takahashi; D Tokunaga; T Hojo; M Fujioka; T Asano; T Hirata; Y Kawahito; Y Satomi; H Nishino; T Tanaka; Y Hirota; T Kubo Journal: Clin Exp Rheumatol Date: 2006 Sep-Oct Impact factor: 4.473
Authors: Anja Möricke; Alfred Reiter; Martin Zimmermann; Helmut Gadner; Martin Stanulla; Michael Dördelmann; Lutz Löning; Rita Beier; Wolf-Dieter Ludwig; Richard Ratei; Jochen Harbott; Joachim Boos; Georg Mann; Felix Niggli; Andreas Feldges; Günter Henze; Karl Welte; Jörn-Dirk Beck; Thomas Klingebiel; Charlotte Niemeyer; Felix Zintl; Udo Bode; Christian Urban; Helmut Wehinger; Dietrich Niethammer; Hansjörg Riehm; Martin Schrappe Journal: Blood Date: 2008-02-19 Impact factor: 22.113
Authors: A Reiter; M Schrappe; W D Ludwig; W Hiddemann; S Sauter; G Henze; M Zimmermann; F Lampert; W Havers; D Niethammer Journal: Blood Date: 1994-11-01 Impact factor: 22.113
Authors: Kathrin Seidemann; Marion Book; Martin Zimmermann; Ulrike Meyer; Karl Welte; Martin Stanulla; Alfred Reiter Journal: Ann Hematol Date: 2006-02-07 Impact factor: 3.673
Authors: Johan G C van Hasselt; Natasha K A van Eijkelenburg; Jos H Beijnen; Jan H M Schellens; Alwin D R Huitema Journal: Br J Clin Pharmacol Date: 2013-07 Impact factor: 4.335
Authors: M A H den Hoed; E Lopez-Lopez; M L te Winkel; W Tissing; J D E de Rooij; A Gutierrez-Camino; A Garcia-Orad; E den Boer; R Pieters; S M F Pluijm; R de Jonge; M M van den Heuvel-Eibrink Journal: Pharmacogenomics J Date: 2014-11-04 Impact factor: 3.550