Biomagnetic liver susceptometry in long-term survivors after bone marrow or stem cell transplantation

Patients with major hematologic malignancy or aplastic anemia were treated with bone marrow (BMT) or stem cell transplantation. Additional transfusion of erythrocyte concentrates during chemotherapy and after BMT is a part of the therapy. As a consequence of the transfusion of red blood cells, iron accumulates in organs, tissues and endocrine glands. In a former study we found increased iron stores in patients with acute lymphoblastic leukemia (ALL) treated by chemotherapy and blood transfusions [1]. To prevent the patients against the potential toxicity of an acute or chronic iron overload, the diagnosis and staging of iron metabolism in these patients is necessary. The most important organ for staging iron overload diseases is the liver, because more than 70% of the total body storage iron is concentrated there. So far, no quantitative data are available in these patients. Currently, the classical invasive liver biopsy with histologic determination of Prussian blue stainable iron and/or chemical determination of iron in the liver biopsy specimens is still the standard method in the diagnosis of clinical relevant iron overload. Among several non-invasive methods (CT, MRI, nuclear resonance scattering, SQUID biomagnetic susceptometry), only MRI and biomagnetic susceptometry have the capability to measure liver iron concentration (LIC) with the sensitivity necessary for clinical use. In more than ten years (1989 2000) SQUID biosusceptometry has been used to assess iron stores in ~ 2000 patients suspected for iron overload [2]. Especially in children, biomagnetic liver susceptometry (BLS) is the method of choice [3]. In the present study, non-invasive iron quantification by biomagnetic liver susceptometry under clinical conditions was used in a group of patients after bone marrow or stem cell transplantation. The main aspect in our study was the incidence and degree of iron overload in those patients, who were at least one year after BMT.