Monitoring Iron Levels in Sickle Cell Disease

It is important to manage iron levels in patients with sickle cell disease who receive transfusions, as excess iron is toxic and can cause liver failure, heart failure, and diabetes, says Thomas D. Coates, MD. The extent of the damage that occurs from iron is a function of how much iron is there and for how long.

It is important to measure ferritin levels, iron concentration in the liver, and transparent saturation to get an accurate picture of whether a patient has iron overload. If transparent saturation exceeds 50%, the toxic form of iron is circulating in the patient, Coates adds. Measuring ferritin is one way to screen for iron overload but the level of ferritin may not correlate well with the level of total body iron. Using magnetic resonance imaging to measure liver iron concentration is an accurate way to measure total iron.

Although most of the package inserts for iron chelation therapies say to start treatment at a ferritin level of 1000 ng/ml, Coates suggests that patients with more modest levels of ferritin can have total body iron levels that are up to five times the normal level. There are also differing opinions as to the appropriate target liver iron level, adds Coates.