Surely, thanks to Popeye, everyone knows that we need iron, and that it circulates in the blood and is one of its components. But many other cells and proteins are involved in the proper functioning of the circulation and our body as a whole. One of them is the protagonist of today’s post: high and low transferrin.
We will look at what exactly this protein is, its function and the normal, high and low values you should be aware of to know what range you should ideally be in. Let’s begin!
What is transferrin?
Transferrin, like haemoglobin or ferritin, is a protein that transports iron in the plasma of many living organisms. It collects iron from the absorption centres in the duodenum to take it to where it is needed. It is produced in the liver, but can also be synthesised (although to a lesser extent) in the brain and other tissues. Transferrin is found in the blood and its main task is to control and regulate the amount of iron circulating in the blood, depending on the body’s needs. To do this, this protein has the ability to bind to the iron, to ‘hook’ it, so to speak, and lead it to where it is needed.
Iron is an essential nutrient for the production of red blood cells. It is particularly sensitive, as the body is not able to produce it naturally, so it must be absorbed from the food we eat. When this nutrient is absorbed from our diet, transferrin is responsible for transporting it through the body. Therefore, the amount of transferrin in the blood depends on the body’s liver function and nutritional status.
In order to know if everything is working properly, there are several levels that can be measured:
- Total iron binding capacity (TIBC). It measures the amount of iron that can be bound by proteins in the blood. Transferrin is the iron-binding protein, so TIBC is able to indirectly measure transferrin availability.
- The free iron-bearing capacity (UIBC). Determines the transferrin reserve capacity. It measures, for example, the part of transferrin that has not yet been saturated with iron. UIBC can be measured either directly or by calculating it with this formula: TIBC – iron = UIBC.
- Serum iron. It measures the total amount of iron in the blood. About half of this nutrient will circulate bound to transferrin. It is needed to calculate both TIBC and UIBC.
- Transferrin saturation. It can be calculated using serum iron levels and TIBC or UIBC. The result will represent the percentage of transferrin saturated with iron. The iron binding sites of transferrin should be 30% saturated.
- Ferritin . It shows the status of the body’s iron stores. If the value is low it means that there is a deficiency of iron and if it is high it means that there is an excess of iron in the body.
When is a transferrin test requested?
Transferrin tests are often ordered in conjunction with other iron-related tests, whether a patient is iron deficient or iron deficient. It is very common for the physician to request it if there are signs of anaemia, especially if the result of the blood count indicates low haemoglobin and haematocrit levels.
The most common symptoms of anaemia are:
- Chronic tiredness, fatigue.
- Dizziness.
- Weakness
- Headaches.
- Skin pallor.
If the physician suspects iron accumulation in a patient or knows of family members with haemochromatosis, a ferritin test should be added to the serum iron and TIBC test. The clinical manifestations of iron overload may vary between individuals, but there are certain symptoms and signs:
- Joint pain.
- Fatigue, weakness.
- Weight loss.
- Lack of energy.
- Abdominal pain
- Loss of sexual desire.
- Hair loss.
- Heart and/or liver problems.
Tests for transferrin levels are also often ordered when iron poisoning is suspected. This is especially true for children who may have accidentally taken an overdose of vitamins or iron-containing supplements.
Only a venous blood sample is needed for the transferrin test, as the physician needs to know the body’s ability to transport iron and help diagnose iron deficiency or overload. No special preparation is needed for the test, but the patient will need to come to the medical centre for the 12-hour fasting blood draw.
Transferrin values
Transferrin values can be classified into 3 blocks: normal, high or low. Each has its own causes and consequences. Balancing the values will depend on many factors, such as age, gender, and the individual’s physical and nutritional conditions.
Normal values. Let’s see what the ideal blood transferrin values are:
- Males: 215 to 360 milligrams per decilitre (mg/dl).
- Women: 250 to 370 milligrams per decilitre (mg/dl).
- Children: 200 to 350 milligrams per decilitre (mg/dl).
Normal levels of CTFH vary between 250-350 micrograms per decilitre. The result will change depending on the sex, age and health status of the person.
High transferrin. Transferrin concentration is commonly used to differentiate microcytic anaemias. In these cases, the red blood cells are smaller than normal.
An elevated transferrin level is considered to be above 360 mg/dl in men and above 370 mg/dl in women. Some studies explain that the most common cause of high transferrin is iron deficiency anaemia or iron deficiency. However, there are also others:
- Pregnancy.
- Polycythaemia.
- Oral contraceptives.
- Hormone therapy with oestrogen.
High transferrin also occurs in iron deficiency anaemia, known as iron deficiency anaemia.
Low transferrin. Low transferrin or hypotransferrinemia occurs when levels are below 215 mg/dl in men and 250 mg/dl in women. The causes of this drop in transferrin can be attributed to:
- Thalassaemia.
- Malnutrition.
- Sickle cell disease.
- Kidney diseases.
- Sideroblastic anaemia.
- Extensive burns.
- Repeated infections.
- Liver disorders (cirrhosis).
- Anaemia due to chronic diseases (cancer).
- Use of medicines (chloramphenicol and glucocorticoids).
Is it possible to normalise levels?
As mentioned above, transferrin levels in the blood depend on the amount of iron and the state of red blood cells. A low level of transferrin is in most cases due to a deficiency of the mineral. The solution would therefore be to increase iron intake.
The foods that can provide our bodies with the most iron are the following:
- Eggs.
- Red meat and liver.
- Lentils and chickpeas.
- Fish and seafood.
- Spinach and peaches.
Eating these foods does not mean that we cannot suffer from low iron levels in our bodies. At Ambar Lab we recommend always consulting a doctor for a proper assessment of the patient’s condition. Only health professionals are trained to identify and treat these diseases.
What is the transferrin saturation index?
The transferrin saturation index is a measure of the percentage of transferrin that is bound to iron in the blood. When transferrin is synthesised, it travels into the bone marrow to form
red blood cells, and to the spleen, liver and muscles for storage as ferritin. This is why its values are so useful for determining a patient’s nutritional status or liver function. The amount of transferrin can vary depending on certain individual factors (liver activity and diet).
Normal transferrin saturation values may vary depending on some individual factors, such as:
- Age.
- Sex.
- The type of diet.
- Genetic and population factors.
Transferrin saturation values should be assessed together with the patient’s medical history and any other complementary examinations that have been performed. Normal saturation values would be:
- Men: 20-50 %.
- Women: 15-50 %.
- Children: 17-44 %.
- Newborns: 56-74 %.
What does the result mean?
Transferrin, TIBC or UIBC results are interpreted taking into account other tests related to iron metabolism. This table summarises some of the alterations that have been observed in tests related to iron metabolism in different diseases:
Conclusions
We already know that the measurement of high or low transferrin is requested when the doctor suspects that there may be too much or too little iron in the body. It measures the body’s ability to transport iron and is intended to help diagnose iron deficiency or overload. At Ambar Lab we offer more than 3,000 laboratory tests to provide an excellent clinical examination service with transparency and professionalism. Our main objective is to respond to the needs of our customers, being at the forefront of technology.
Our clinical laboratory supports the maintenance of public health. Through our work, a diagnosis can be confirmed or not. The technicians and professionals of Ambar Lab analyse biological samples to study them in order to study, prevent, diagnose and treat diseases. If you need any laboratory analysis, do not hesitate to contact us. We will be happy to help you with any questions you may have.
