Uptake and storage of retinol and retinyl esters in bone marrow of children with acute myeloid leukemia treated with high‐dose retinyl palmitate

:  Twenty-one children with AML, who achieved complete remission with cytostatics, were treated with high doses of retinoids after remission was achieved. They were given 52 μmol retinyl palmitate/m2 (50000 International Units/m2) daily for at least 2 years thereafter. Thirteen of the children are still in complete remission with a mean observation time of 103 months. Due to the positive effects of retinoids seen in the treatment of AML, we have studied uptake of lipoprotein-associated retinyl esters in bone marrow cells and peripheral leukocytes in vivo. An oral load of 104 μmol/m2 (100000 International Units/m2) retinyl palmitate resulted in a doubling of the concentration of total retinol in bone marrow cells and peripheral leukocytes after 5 hours. However, in the fasting state no significant difference was observed between the content of total retinol in bone marrow cells from controls and from patients receiving retinyl palmitate daily for years. Our study suggests that bone marrow cells take up retinyl esters postprandially, but do not store retinoids.