Iron studies

5 mL blood in lithium heparin or plain tube.

Suspected iron deficiency, iron overload, acute iron poisoning (see Iron toxicity). The assessment of iron deficiency or overload may be complicated by the presence of an acute phase response or hepatocellular disease. In general, serum ferritin is the preferred test for the assessment of iron deficiency, however levels may be normal (up to 100 µg/L) when iron deficiency coexists with an acute phase response. Soluble transferrin receptor levels are more useful, as they are not affected in an acute phase response; levels are normal in Anaemia of chronic disease uncomplicated by iron deficiency. An alternative approach to the patient with suspected iron deficiency and/or chronic inflammatory disease is to assess the haemoglobin response to iron therapy.