Content Reviewed April 2013 | Author: The Haemochromatosis Society © 2013
Tests & Treatment
If you think you might have haemochromatosis make an appointment with your Doctor, it might help to take a copy of the information for Professionals with you. Diagnosis is often made through the following tests.
- Transferrin Saturation (TS)
TS is the ratio of two simple blood tests, which indicates iron accumulation. Serum iron is divided by total iron binding capacity (TIBC) to give the TS percentage. Normal average is 30% (slightly higher in men than women). If on two occasions this is over 50% in men or 45% in women, GH is very likely and one should proceed to measure:
- Serum Ferritin
This indicates the amount of iron stored in the body. Levels significantly over 300µg/l [micrograms per litre] in men and post menopausal women, and 200µg/l in women are further evidence of GH. It should be realised that in the early stages of iron accumulation, serum ferritin may be within the normal range. Raised TS with a normal serum ferritin level does not rule out a diagnosis of GH.
- Gene Test
A simple blood test for the HFE gene mutation is positive in over 95% of those affected. It will identify family members at risk of loading iron.
- Liver Biopsy
A small sample of the liver is removed using a biopsy needle, which shows whether tissue damage such as cirrhosis is present. It is recommended when the serum ferritin reading is over 1000µg/l, there is evidence of abnormal liver function, or the HFE test is negative.
The simple and effective treatment consists of regular removal of blood. Known as venesection therapy or phlebotomy, the procedure is the same as for blood donors. Every pint of blood removed contains a quarter of a gram of iron.
The body then uses some of the excess stored iron to make new red blood cells. Venesection will usually be performed once a week, depending on the degree of iron overload. Treatment may need to be continued at this frequency for up to 2 years, occasionally longer.
During the course of treatment, the serum ferritin levels are monitored, indicating the size of the remaining iron stores. Treatment should usually continue until the serum ferritin level reaches 20µg/l (indicating minimal or absent iron stores).
This is not the end of the story. Excess iron will continue to be absorbed so the individual will need occasional venesections (maintenance therapy), on average every 3 to 4 months, for the rest of his or her life. Monitoring of transferrin saturation and serum ferritin is used to assess whether venesection is required more or less often. The transferrin saturation should be maintained below 50% and the serum ferritin below 50µg/l.
The graph on the right gives an example of how treatment may affect blood iron levels during treatment. Serum ferritin decreases steadily, but transferrin saturation remains high until iron deficiency occurrs, then falls sharply.