Hepatic Iron Concentration and Total Body Iron Stores in Thalassemia Major

Abstract

The hepatic iron concentration is a reliable indicator of total body iron stores in patients with thalassemia major. In patients with transfusion-related iron overload, repeated determinations of the hepatic iron concentration can provide a quantitative means of measuring the long-term iron balance.

Reference method for measurement of the hepatic iron concentration

“…The second condition is that the liver-biopsy specimen is adequate, 1 mg dry weight; variability increases with smaller samples. No complications were observed with liver biopsy, extending the record of safety of liver biopsy in expert hands [3][4][5]. These results corroborate previous observations from these and other investigators [5][6][7] that support chemical measurement of the iron concentration in a liver-biopsy specimen as the reference standard for measurement of the hepatic iron concentration.…”

“…Reports of variability in the hepatic iron concentration in different areas of the liver have generally been restricted to studies of cirrhotic livers [10][11][12]; data are lacking in patients with transfusional iron overload without cirrhosis. Even so, the close relationship observed between the hepatic iron concentration and total body iron stores [4] in transfused patients with thalassemia who were free of cirrhosis suggests that the extent of variability is limited.An alternative view of the reference method for measurement of the hepatic iron concentration is that magnetic resonance imaging (MRI), recommended in a variety of guidelines, has become the de facto technique. Nonetheless, since acceptance of the manuscript by Urru et al…”

“…Hepatic iron concentrations measured in deparaffinized samples were a mean of 23% greater than those in desiccated tissue from fresh liver specimens [6]. The minimum weight for an adequate liver sample for analysis remains uncertain; evidence has been provided both for thresholds of 0.4 mg dry weight [8,9] and for 1 mg dry weight [1,4,5]. Reports of variability in the hepatic iron concentration in different areas of the liver have generally been restricted to studies of cirrhotic livers [10][11][12]; data are lacking in patients with transfusional iron overload without cirrhosis.…”

Reproducibility of liver iron concentration measured on a biopsy sample: A validation study in vivo

“…Details on specimen management, biopsy procedure and iron determinations have been described elsewhere [6]. Briefly, from a single cutaneous 2-3 mm cut two separate samples were obtained directing the needle with a different-opposite angle inside the liver right lobe.…”

“…On the basis of our previous experience [6], in which we demonstrated an eight times wider variability in prediction iron stores by liver iron concentration if biopsy specimen gross weight was <1 mg dry weight, biopsy couples were divided into two groups according to their gross weight (couples whose both samples gross weight were 1 mg dw versus biopsy couples whose one or both samples had a specimen gross weight <1 mg dw). All analyses were carried out using SPSS 19 software.…”