Rationale: Recent studies showed that ascorbic acid (AA) stimulates proliferation and maturation of T lymphocytes and NK cells. Chemotherapy results in depletion of those cells and thereby an increased infection rate. A pilot study showed low levels of AA in the plasma of several patients after chemotherapy for hematological malignancies. AA suppletion could be beneficial to the recovery of the immune system in these patients. But before an intervention study can be undertaken, further understanding of changing over time of AA levels and the relationship with the immune status after chemotherapy is necessary.~Objective: The aim of this pilot study is to evaluate the changing over time of AA levels in plasma and in leukocytes before and during chemotherapy treatment for several different groups of patients and compare that to healthy controls. In this way we want to identify the patients were further interventions could be useful and use the data in the development of an intervention study for power calculations and to identify the primary endpoint.~Study design: observational study~Study population: There will be 6 different groups of participants in the study: two groups of patients that receive clinical intensive chemotherapy (acute leukemia and high dose chemotherapy with autologous stem cell rescue), two groups of patients that receive relatively mild chemotherapy in outpatient setting (colon cancer and lung cancer) and two control groups. All participants will be adults and recruited at the MUMC+. In total there will be 150 participants.~Main study parameters/endpoints: Influence of chemotherapy on AA levels in plasma and in leukocytes.~Nature and extent of the burden and risks associated with participation, benefit and group relatedness:~If participants really have a lack of AA after chemotherapy, AA supplementation could be beneficial for the immune recovery in many future patients on chemotherapy. However, the participants cannot benefit yet, because this study does not interfere with current clinical practice. The risks associated with participation in this study are low. Venous blood sampling is performed by skilled and experienced laboratory technicians. For the study, only a small amount of blood, 5 to 7 times 17 ml is needed. Therefore no harm can be expected. Blood withdrawal could result in a hematoma, but this is usually not harmful. Bleedings from the blood withdrawal are usually negligible.
Rationale: Recent studies showed that ascorbic acid (AA) stimulates proliferation and maturation of T lymphocytes and NK cells. Chemotherapy results in depletion of those cells and thereby an increased infection rate. A pilot study showed low levels of AA in the plasma of several patients after chemotherapy for hematological malignancies. AA suppletion could be beneficial to the recovery of the immune system in these patients. But before an intervention study can be undertaken, further understanding of changing over time of AA levels and the relationship with the immune status after chemotherapy is necessary.~Objective: The aim of this pilot study is to evaluate the changing over time of AA levels in plasma and in leukocytes before and during chemotherapy treatment for several different groups of patients and compare that to healthy controls. In this way we want to identify the patients were further interventions could be useful and use the data in the development of an intervention study for power calculations and to identify the primary endpoint.~Study design: observational study~Study population: There will be 6 different groups of participants in the study: two groups of patients that receive clinical intensive chemotherapy (acute leukemia and high dose chemotherapy with autologous stem cell rescue), two groups of patients that receive relatively mild chemotherapy in outpatient setting (colon cancer and lung cancer) and two control groups. All participants will be adults and recruited at the MUMC+. In total there will be 150 participants.~Main study parameters/endpoints: Influence of chemotherapy on AA levels in plasma and in leukocytes.