Interpreting raised serum ferritin levels

#### The bottom line A 60 year old businessman attended his general practitioner after an insurance medical examination at which abnormal liver function tests had been noted (alanine aminotransferase 70 IU/L (normal range 10-40 IU/L) and γ-glutamyltransferase 120 IU/L (normal range 0-37 IU/L)). He was otherwise fit and well and not taking regular medication. His general practitioner noted that his full blood count and renal function were normal, and requested hepatitis B and C serology (which were negative) and serum ferritin level, which was 567 µg/L (normal range 24-300 µg/L). Ferritin is an intracellular iron storage protein and a marker of iron stores. Normal serum ferritin levels vary between laboratories but generally concentrations >300 µg/L in men and postmenopausal women and >200 µg/L in premenopausal women are regarded as elevated.1 Low ferritin values provide absolute evidence of iron deficiency.2 Raised levels often indicate iron overload, but they are not specific, as ferritin is an acute phase protein and is also released from damaged hepatocytes; thus levels are elevated in inflammatory disorders, liver disease, alcohol excess, or malignancy.3 4 Raised ferritin levels therefore require further investigation in primary care to determine if they truly represent iron overload. It is critical …