Effective binding of free iron by a single intravenous dose of human apotransferrin in haematological stem cell transplant patients

Myeloablative treatment results in iron accumulation and the appearance of non-transferrin-bound iron (NTBI) in the circulation, which may contribute to treatment-related organ damage and susceptibility to infections. The aim of this study was to investigate the efficacy of human apotransferrin in the binding of NTBI in patients receiving an allogeneic stem cell transplant after myeloablative conditioning. A single intravenous 100 mg/kg dose of apotransferrin was given to six adult patients on d 3 after the transplantation. Initially, all patients had serum transferrin saturation above 80% and NTBI in their serum. After the apotransferrin injection, serum NTBI became undetectable in all patients and transferrin saturation decreased to 30-50%. Serum transferrin increased by an average of 1.95 g/l. The administered apotransferrin was subsequently converted into monoferric and diferric transferrin forms. NTBI reappeared and transferrin saturation again exceeded 80% 12-48 h after the injection in four patients and after 6 d in one patient. NTBI remained non-detectable for the whole 12 d follow-up period in one patient. The apotransferrin injection was well tolerated and no adverse events with probable association with the apotransferrin were observed. Repeated apotransferrin infusions might completely eliminate NTBI and iron-induced toxicity during myeloablative therapy.