Minimal residual disease (MRD) in acute myeloid leukemia (AML) is of major prognostic importance. The genetic landscape of AML is characterized by numerous somatic mutations, which constitute potentia Show more
Minimal residual disease (MRD) in acute myeloid leukemia (AML) is of major prognostic importance. The genetic landscape of AML is characterized by numerous somatic mutations, which constitute potential MRD markers. Leukemia-specific mutations can be identified with exome sequencing at diagnosis and assessed during follow-up at low frequencies by using targeted deep sequencing. Our aim was to further validate this patient-tailored assay for substitution mutations. By applying a statistical model, which corrects for position-specific errors, a limit of detection for single nucleotide variations of variant allele frequency (VAF) of 0.02% was achieved. The assay was linear in MRD range (0.03% to 1%) with good precision [CV, 4.1% (2.2% to 5.7%) at VAF 1% and 13.3% (8.8% to 19.4%) at VAF 0.1%], and low relative bias [7.9% (2.5% to 15.3%) at VAF 1%]. When applied to six childhood AML cases and compared with multiparameter flow cytometry for MRD analysis, deep sequencing showed concordance and superior sensitivity. Further high concordance was found with expression of fusion transcripts RUNX1-RUNX1T1 and KMT2A-MLLT10. The deep sequencing assay also detected mutations in blood when VAF in bone marrow exceeded 0.1% (n = 19). In conclusion, deep sequencing enables reliable detection of low levels of residual leukemic cells. Introduction of this method in patient care will allow for highly sensitive MRD surveillance in virtually every patient with AML. Show less
In this study we have used mass spectrometry in order to characterize the HDL lipidome in three groups of women from the DIWA cohort; one control group, plus two groups with type 2 diabetes with insul Show more
In this study we have used mass spectrometry in order to characterize the HDL lipidome in three groups of women from the DIWA cohort; one control group, plus two groups with type 2 diabetes with insulin resistance; one dyslipidemic and one normolipidemic. The aim was to investigate whether dyslipidemia is required in addition to insulin resistance for the occurrence of an altered HDL lipidome, which in turn might impact HDL functionality. The dyslipidemic type 2 diabetic subjects were distinguished by obesity, hypertriglyceridemia with elevated apoC3, low HDL-cholesterol and chronic low grade inflammation. In a stepwise multivariate linear regression analysis, including biomarkers of dyslipidemia and insulin resistance as independent variables, only dyslipidemia showed a significant correlation with HDL lipid classes. Small HDL-particles predominated in dyslipidemic subjects in contrast to the normolipidemic diabetic and control groups, and were enriched in lysophosphatidylcholine (+13%), a product of proinflammatory phospholipases, and equally in two core lipids, palmitate-rich triacylglycerols and diacylglycerols (+77 %), thereby reflecting elevated CETP activity. Dyslipidemic small HDL particles were further distinguished not only as the primary carrier of ceramides, which promote inflammation and insulin resistance, but also by a subnormal plasmalogen/apoAI ratio, consistent with elevated oxidative stress typical of type 2 diabetes. From these data we conclude that in type 2 diabetes, dyslipidemia predominates relative to hyperglycemia for the occurrence of an altered HDL lipidome. Furthermore, dyslipidemia alters the cargo of bioactive lipids, with implications for HDL function. Show less