What is new in iron overload?

Abstract

Children with severe chronic hemolytic anemia or congenital erythroblastopenia are transfusion dependent. Long-term transfusion therapy prolongs life but results in a toxic accumulation of iron in the organs. The human body cannot actively eliminate excess iron. Therefore, the use of a chelating agent is required to promote excretion of iron. So far, iron chelation has been done by subcutaneous infusion of deferoxamine given over 10 h, 5-6 days per week. Compliance is poor and chelation often insufficient. Ferritin measurements and sometimes liver biopsies are used to evaluate the iron burden in the body. At the present time, new iron chelators that can be given orally are available. Furthermore, magnetic resonance imaging (MRI) assessment of tissue iron is a noninvasive and highly reproducible method, which is able to quantitate organ iron burden. In conclusion, iron overload can be measured more accurately with noninvasive methods such as MRI. Deferasirox is a once-daily oral therapy for treating transfusional iron overload, which improves patient compliance and quality of life.

Fig. 1

Liver biopsy (Perls stain): iron deposits are in blue. Courtesy of B. Turlin, Pathology Department, University Hospital of Rennes

Fig. 2

Gradient echo images of liver collected by J. Wood [13] at four different echo times. The top four images were collected from a patient having a liver iron of 6 mg/g. The bottom four images were collected from a normal volunteer. All images darken as the echo time (TE) lengthens, but the iron-heavy tissue darkens faster. The half-life of this process is called T2* and the rate is called R2* (R2* = 1,000/T2*)

Fig. 3

Gradient echo imaging illustrating discordant iron loading of the liver and heart. a Heavy liver iron loading (dark tissue) with heart sparing image. b Heavy cardiac iron loading with no liver deposition. From [13]