Fig. 1
Metabolic changes in AML patients undergoing intensive chemotherapy. a Patient characteristics. CR1 first complete remission. *UPN#1 developed a lethal fungal pneumonia while in remission after the first consolidation CT cycle. **UPN#3 underwent allogeneic hematopoietic stem cell transplantation in CR1 and subsequently relapsed. b Outline of the study design. c Superposition of representative 1H Carr-Purcell-Meiboom-Gill (CPMG) spectra of BM at tp1H (black line) and tp9H (red line) acquired at 37 °C on a Bruker Avance 600-MHz spectrometer. The 1H CPMG NMR experiment is based on a pulse sequence that strongly reduces the NMR signals deriving from large molecules; herewith, molecules with high molecular weight are essentially invisible in the 1H spectrum, thus facilitating spectra interpretation and small molecule identification in the presence of large proteins and lipoproteins. Peaks correspond to the different metabolites: 1—high-, low-, and very low-density lipoproteins (HDL, LDL, VLDL) CH3; 2—isoleucine; 3—leucine; 4—valine; 5—3-aminoisobutyrate; 6—3-hydroxybutyrate; 7—LDL/VLDL CH2; 8—lactate; 9—alanine; 10—lipids CH2CH2CO; 11—acetate; 12—lipids CH2C=C; 13—N-acetyl-glycoproteins (NAG) NHCOCH3; 14—glutamine; 15—lipids CH2CO; 16—acetoacetate; 17—citrate; 18—lipids C=CCH2C=C; 19—creatinine; 20—creatine; 21—creatine phosphate; 22—glucose; 23—glycerol of lipids CHOCOR; 24—α glucose; 25—poly-unsaturated fatty acids (UFA); 26—tyrosine; 27—phenylalanine; 28—histidine; 29—formate. d OPLS-DA score plot for pooled PB and BM samples collected at diagnosis and typing positive (blue circles; n = 6) or negative (green circles; n = 12) for missense mutations in the IDH1/2 genes. OPLS-DA with N = 18, CV ANOVA p = 0.059, R 2 = 0.93, and Q 2 = 0.615. The area under the curve (AUC) of the ROC analysis was 0.86 (p < 0.001). e Metabolites discriminating AML patients with or without IDH gene mutations. Loadings indicate how much the variables, i.e., the metabolites, contribute to the model. Shown are loadings with jack-knifed confidence interval. The metabolites significantly contributing to the model were selected based on variable importance in projection >1 and jack-knifed confidence interval of loadings not crossing the zero line. Positive loading values (blue bars) indicate the metabolites increased in patients with mutated IDH, while negative values (green bars) are associated with increased levels in patients with wild-type IDH. Note that the concentration levels of the classical IDH mutation oncometabolite (R)-2-hydroxyglutarate were below the NMR detection limit and that because of the overlap of the resonances associated to CH2 groups of high-, low- and very low-density lipoproteins (HDL, LDL, VLDL) and the CH2C=C groups of different lipid molecules it was not possible to establish their specific contribution to the model. f OPLS-DA score plot for pooled PB and BM samples of patients at diagnosis (tp1H, blue circles; n = 18) vs remission after chemotherapy (pooling samples after induction, tp5H, and after first consolidation, tp9H, green circles; n = 29). OPLS-DA model with N = 47, CV-ANOVA p = 0.006, R 2 = 0.99, and Q 2 = 0.671. The AUC of the ROC analysis was 0.73 (p < 0.001). g Metabolites discriminating AML patients at diagnosis and in remission after chemotherapy. Positive loading values (blue bars) indicate the metabolites increased in AML patients at tp1H, while negative values (green bars) are associated with increased metabolite levels at tp5H + tp9H