TY - BOOK
T1 - Mathematical Modelling of Myeloproliferative Neoplasms and Hematopoietic Stem Cells
AU - Pedersen, Rasmus Kristoffer
N1 - Vejledere: Johnny T. Ottesen, Morten Andersen og Hans C. Hasselbalch
PY - 2020/11/20
Y1 - 2020/11/20
N2 - The Philadelphia-negative myeloproliferative neoplasms (MPNs) is a group of blood cancers which include the diseases essential thrombocythemia (ET), polychytemia vera (PV) and primary myelofibrosis (PMF). Evidence suggests that ET, PV and PMF are closely connected and represent different stages along a biological continuum. In recent years, chronic inflammation has been found to be an important driver of cancers in general and of the Philadelphia-negative MPNs in particular. The concept of inflammation driving a biologically continuum of disease makes MPNs apt for investigations through mathematical modelling, with promise of improved patient prognosis and advancements in treatment.In this thesis, we describe and analyse three mechanism-based mathematical models. All three models are described using systems of ordinary differential equations (ODE). This is done in an effort to gain insight into blood cancers in general and about a cohort of patients enrolled in the clinical trial \DALIAH" in particular (EudraCT number: 2011-001919-31). The patients considered here were all diagnosed with MPNs and treated with pegylated interferon-α (IFN) over a five year period. The first model was proposed by Andersen et al. (2017) and describes the connection between chronic inflammation and the progression of MPN. A model extension allows us to relate patientspecific IFN-dose scheduling with patient data of leukocyte-counts, thrombocyte-counts and measurements of the JAK2V617F allele burden, showing good agreement between the dynamics of the mathematical model and the behaviour observed in data.A novel mathematical model of the hematopoietic stem cells (HSC) is proposed. Mathematical analysis of the model suggests a notion of HSC fitness, found to determine long-term competition between HSC clones within the bone-marrow microenvironment. A model reduction is deemed appropriate, and HSC fitness is found to be principal in the behaviour of the reduced model as well.We combine the two models into a single model describing both HSC-mechanisms, blood-cell production and the effect of chronic inflammation on MPN progression. This combined model can be used to investigate and simulate a wide range of scenarios, allowing us to make novel hypotheses about the behaviour of HSC and the entire hematopoietic system. In particular, we are able to interpret the effect IFN-treatment has on MPN-diagnosed patients, by relating the model to data of individual patients. For the IFN-treated MPN patients of the DALIAH trial, we observed a difference in the time-scale of the response of blood-cell counts and of the JAK2V617F allele burden. Based on our model-based investigations, we hypothesize that this difference in response is due to a two-fold effect of IFN: Production of blood-cells is inhibited for both healthy and malignant clones on a short time-scale, while malignant stem cells are substantially inhibited on longer time-scales.Finally, we present a proof-of-concept of how mathematical modelling calibrated to patientmeasurements at diagnosis can make predictions on the level of individual patients. We hypothesize that, with sufficient collection of patient-data and model-calibration, mathematical modelling could be an important prognostic tool in the clinic in the near future, allowing for improved treatment of MPNs using IFN.
AB - The Philadelphia-negative myeloproliferative neoplasms (MPNs) is a group of blood cancers which include the diseases essential thrombocythemia (ET), polychytemia vera (PV) and primary myelofibrosis (PMF). Evidence suggests that ET, PV and PMF are closely connected and represent different stages along a biological continuum. In recent years, chronic inflammation has been found to be an important driver of cancers in general and of the Philadelphia-negative MPNs in particular. The concept of inflammation driving a biologically continuum of disease makes MPNs apt for investigations through mathematical modelling, with promise of improved patient prognosis and advancements in treatment.In this thesis, we describe and analyse three mechanism-based mathematical models. All three models are described using systems of ordinary differential equations (ODE). This is done in an effort to gain insight into blood cancers in general and about a cohort of patients enrolled in the clinical trial \DALIAH" in particular (EudraCT number: 2011-001919-31). The patients considered here were all diagnosed with MPNs and treated with pegylated interferon-α (IFN) over a five year period. The first model was proposed by Andersen et al. (2017) and describes the connection between chronic inflammation and the progression of MPN. A model extension allows us to relate patientspecific IFN-dose scheduling with patient data of leukocyte-counts, thrombocyte-counts and measurements of the JAK2V617F allele burden, showing good agreement between the dynamics of the mathematical model and the behaviour observed in data.A novel mathematical model of the hematopoietic stem cells (HSC) is proposed. Mathematical analysis of the model suggests a notion of HSC fitness, found to determine long-term competition between HSC clones within the bone-marrow microenvironment. A model reduction is deemed appropriate, and HSC fitness is found to be principal in the behaviour of the reduced model as well.We combine the two models into a single model describing both HSC-mechanisms, blood-cell production and the effect of chronic inflammation on MPN progression. This combined model can be used to investigate and simulate a wide range of scenarios, allowing us to make novel hypotheses about the behaviour of HSC and the entire hematopoietic system. In particular, we are able to interpret the effect IFN-treatment has on MPN-diagnosed patients, by relating the model to data of individual patients. For the IFN-treated MPN patients of the DALIAH trial, we observed a difference in the time-scale of the response of blood-cell counts and of the JAK2V617F allele burden. Based on our model-based investigations, we hypothesize that this difference in response is due to a two-fold effect of IFN: Production of blood-cells is inhibited for both healthy and malignant clones on a short time-scale, while malignant stem cells are substantially inhibited on longer time-scales.Finally, we present a proof-of-concept of how mathematical modelling calibrated to patientmeasurements at diagnosis can make predictions on the level of individual patients. We hypothesize that, with sufficient collection of patient-data and model-calibration, mathematical modelling could be an important prognostic tool in the clinic in the near future, allowing for improved treatment of MPNs using IFN.
M3 - Ph.D. thesis
T3 - IMFUFA-tekst : i, om og med matematik og fysik
BT - Mathematical Modelling of Myeloproliferative Neoplasms and Hematopoietic Stem Cells
PB - Roskilde Universitet
CY - Roskilde
ER -