Iron
- Description
- Iron by ICP-MS
- Clinical details
- Iron may be considered a trace element if the large amounts present in haemoglobin are discounted. The recommended daily intake is 10-15 mg per day, of which only 1-2 mg is absorbed. The main transport protein for iron is transferrin, which is synthesised in the liver at a rate inversely proportional to body stores. Ferritin is an iron storage protein found in most cells of the body, particularly the liver, and provides a readily available reserve. Haemosiderin is an insoluble aggregate protein also found primarily in the liver during excessive storage and from which iron is less readily available. Iron deficiency is one of the most prevalent disorders, even in developed countries. It may either be due to inadequate dietary intake or chronic blood loss. Acute iron toxicity from overdosage of inorganic iron tablets is the commonest acute poisoning in children. Chronic iron overload may arise from genetic haemochromatosis in which there is excessive iron absorption or secondary to repeated transfusions (transfusion siderosis in sickle cell disease or thalassaemia), or to alcoholic liver disease. Genetic haemochromatosis is due to mutations in the HFE gene (C282Y and H63D) and is primarily found in Caucasians. Neonatal haemochromatosis is a rare, but particularly severe cause of iron overload and is unrelated to the adult form. Liver transplantation within the first few weeks of life is required for survival. A raised transferrin saturation (> 65%) is strongly suggestive of haemochromatosis. Until recently, diagnosis was usually confirmed by hepatic iron measurements, but today molecular techniques for identification of the above mutations is more common and less invasive. Treatment of transfusion siderosis is with the iron chelator desferrioxamine. Measurement of urinary iron excretion during chelation therapy can help optimise the dosage.
- Reference range
24 H urine : < 1.0 µmol/24h,
Random Urine : <1.0 µmol/mmol creatinine
Liver Biopsy : <1500 µg/g Dry Weight,
Hepatic Iron Index : < 0.7
- Synonyms
- Iron, urine, tissue
- Testing site
- Synnovis : Reference Services : King's College Hospital
- Laboratory
- Trace Elements
- Sample type and volume required
- Liver biopsy, 20 ml urine (Portion of 24 hour collection [acid-washed bottle] in sterile universal, record total volume on sample tube or request form). Random urine collection in 25ml Sterilin Universal containers.
- Call in advance
- No
- Special sample instructions
Liver biopsy- At least one centimetre of liver tissue sample is required. Sample should be transferred from biopsy needle without delay. If the specimen is to be divided (e.g. piece required for histology) a new/clean scalpel should be used. A clean Sterilin universal container is acceptable. The tissue sample should not be placed in Formalin or saline, as this can lead to contamination or leaching out of certain elements. If a sample embedded in paraffin wax is available, and there is no possible way of getting a fresh liver sample, then the embedded sample can be utilised (provided there is enough tissue) to estimate liver Copper concentration. There is however, a potential risk of contamination during the de-waxing procedure.
- Storage and transport
- Stable at 4°C. Send by overnight first class post. Keep liver tissue samples in paraffin wax blocks at room temperature.
- Turnaround time
- 10 working days for urine and tissue iron
- Contacts
Toxicology Department at King’s Hospital
Phone: 020 3299 5881
Email: kch-tr.toxicology@nhs.net
King’s College Hospital
Bessemer Wing – 3rd Floor
Denmark Hill
London SE5 9RSTrace Elements Laboratory at King’s College Hospital
Phone: 020 3299 3008
Email: kishor.raja@nhs.net
King’s College Hospital
Bessemer Wing – Top Floor
Denmark Hill
London SE5 9RS