Characterization of hepatic and cardiac iron deposition during standard treatment of anaemia in haemodialysis

BackgroundParenteral iron is integral in the treatment of anaemia of chronic kidney disease patients on haemodialysis (HD). However, increased liver iron concentration (LIC) can result from such treatment, and this correlates poorly with serum ferritin or transferrin saturation values. It is unclear whether increased cardiac iron concentration also occurs in this setting. We aimed to evaluate the relationship of intravenous iron supplementation to hepatic and cardiac iron deposition in chronic HD subjects. MethodsA cohort of 10 patients on chronic HD for at least 1year underwent MRI-based quantitation of hepatic and cardiac iron content to evaluate the relationship between intravenous iron supplements and hepatic and cardiac iron deposition. The results were compared against the cumulative parenteral iron dose and serum iron markers. ResultsThe median age was 61years (95% confidence interval (CI) 50-71), HD time 2.5years (95%CI 2.0-5.3) and cumulative iron dose 4300mg (95%CI 2110-9045). Hepatic iron concentration was elevated in eight of 10 subjects (median 46mmol/kg, range 31-76). Cardiac iron levels were within the reference range in all subjects. There was poor correlation between conventional haematinic values and either LIC or cardiac iron levels. None of the study subjects exhibited elevated cardiac iron concentration. ConclusionWhilst HD patients receiving standard parenteral iron therapy have elevated LICs, this is not associated with cardiac iron deposition. Transferrin saturation and serum ferritin levels are poor markers of either liver or cardiac iron deposition in HD subjects. Summary at a Glance The authors evaluated cardiac and hepatic iron deposition by MRI-based quantitation in hemodialysis patients who received intravenous iron supplements. They showed elevated hepatic iron deposition which was poor correlation with conventional haematic iron markers. This study showed interesting issues regarding iron overload in hemodialysis patients.