Sideremia measures the amount of iron present in the liquid part of the blood (serum). Iron is a very important element for the body and, under normal conditions, about 60-80% of the amount introduced with the diet is used for the production of hemoglobin (red blood cell protein responsible for transporting oxygen) and myoglobin (protein contained in the muscles). Iron not used for the production of other proteins and enzymes is stored in the tissues in the form of ferritin.
Purpose of the test
The iron test is used to measure the amount of iron bound to transferrin in the liquid component of the blood (serum). Transferrin is a protein that has the function of transporting iron from the intestine to all the cells in the body that use it.
When it is required
The examination (test) is often prescribed when the doctor suspects an increase or decrease in iron values. In the former case this can occur due to a genetic condition, repeated blood transfusions or, rarely, from ingestion of excess iron (usually in children). Too much iron can lead to progressive and excessive accumulation that can cause damage to various organs, such as the liver, heart and pancreas.
The second case can occur if not enough iron is introduced in the diet. As a result, the concentration levels in the blood drop and the stocks accumulated in the tissues are progressively used, causing iron deficiency anemia. To ascertain (diagnose) it, a single examination is not enough. When the doctor suspects it, in addition to the test that measures the amount of iron in the blood (sideremia) also prescribes the dosage of the amount of iron deposited in the form of ferritin. The ferritin analysis measures the amount of iron reserves in the body.
Substances that can cause an increase in iron levels include:
- contraceptive pill
- estrogen pills and preparations
- iron supplements
- alcoholic beverages
- methyldopa, medicine used to treat high blood pressure (arterial hypertension)
- chloramphenicol (antibiotic)
Substances that can cause low iron levels include:
- ACTH (adrenocorticotropic hormone produced by the adenohypophysis)
- colchicine (substance used for the treatment of gout attack)
- desferoxamine (iron chelating drug, which binds iron and allows its elimination)
- methicillin (antibiotic drug derived from penicillin)
- testosterone (hormone belonging to the androgen group)
The dosage of iron in the blood (sideremia) measures the amount of iron bound to transferrin, which has the function of transporting it from the intestine to the cells that use it.
To perform the test, after fasting for at least 12 hours (only drinking water is allowed if desired), a small amount of blood must be drawn from a vein in the arm. No iron supplement should be taken in the 24 hours prior to the test: being rapidly absorbed from food or tablets, it could distort the results.
The amount of iron in the blood varies during the day and from one day to the next. The sideremia, therefore, is often required in combination with other tests such as: transferrin, ferritin, TIBC (total capacity of transferrin to bind iron) and UIBC (reserve capacity of transferrin, i.e. which is not yet bound to iron).
In people with anemia, sideremia can help determine whether it is due to iron deficiency or a chronic disease.Results
The values considered normal may differ from laboratory to laboratory because they depend on many factors (age, sex, the reference population, the methods used for the analysis) and, therefore, it is not possible to indicate them.
The increase in sideremia can be determined by:
- genetic diseases, such as hemochromatosis
- excessive introduction of iron through repeated transfusions
- intramuscular injections of iron
- lead poisoning
- liver or kidney disease
Low iron levels can cause anemia and are usually due to:
- heavy or prolonged bleeding
- rapid growth in children
- rarely on a low iron diet
Among the various causes of anemia, iron deficiency is quite frequent, to be evaluated especially if associated with high transferrin or TIBC values. If the iron deficiency is not corrected, in the long run the iron levels decrease significantly, transferrin and TIBC increase and anemia will begin to manifest.
Conversely, in chronic (long-term) diseases, low levels of iron in the blood are associated with low levels of transferrin or TIBC.
In the event of altered iron values, it is necessary to consult your doctor to identify the causes and take the correct treatment.