Extreme hyperferritinaemia; clinical causes.

There are many causes of raised serum ferritin concentrations including iron overload, inflammation and liver disease to name but a few examples. Cases of extreme hyperferritinaemia (serum ferritin concentration equal to or greater than 10 000 ug/l) are being reported in laboratories but the causes of this are unclear. We conducted an audit study to explore this further. Extreme hyperferritinaemia was rare with only 0.08% of ferritin requests displaying this. The main causes of extreme hyperferritinaemia included multiple blood transfusions, malignant disease, hepatic disease and suspected Still's disease.