SEQUENTIAL-CHANGES IN SERUM IRON AND FERRITIN IN PATIENTS UNDERGOING HIGH-DOSE CHEMOTHERAPY AND RADIATION WITH AUTOLOGOUS BONE-MARROW TRANSPLANTATION - POSSIBLE IMPLICATIONS FOR TREATMENT RELATED TOXICITY

In an effort to define the pattern of iron flux during high-dose chemotherapy or chemo/radiotherapy, we prospectively measured serum iron, iron binding capacity, and ferritin in patients undergoing autologous bone marrow transplantation for various malignancies. Sequential measurement of serum iron from days -7 to +12 was carried out in 88 evaluable patients, and simultaneous measurement of iron, ferritin, and total iron binding capacity was carried out in 32 patients. We found that there was a predictable rise in serum iron on day -2 or -3, and that this was accompanied by an increase in the saturation of transferrin. In addition, there was a similar increase in serum ferritin levels, which peaked by day +2. We suggest that the timing of this change in serum iron and saturation of transferrin may be important in mediating endothelial cell damage and, hence, organ toxicity in the setting of AuBMT. Based on these findings, we suggest that large clinical studies could be a source of patient samples to measure surrogate endpoints such as lipid peroxidation products (malondialdehyde or isoprostanes), or protein oxidation products following high-dose chemo/radiotherapy to determine the role of iron in cellular injury. It is possible that pharmacological manipulations to reduce free radical production or to chelate iron during the days prior to bone marrow reinfusion might help to reduce tissue injury in the setting of bone marrow transplantation.