The iron test measures the amount of iron that is circulating in the liquid part of blood bound to transferrin (a transport protein). Iron is an essential trace element in your blood. It is necessary for forming healthy red blood cells. Approximately 70% of iron absorbed from the diet is used to form haemoglobin, the protein within red blood cells which carries oxygen through your body. Iron is also used in the production of some other proteins, such as myoglobin in muscle, and various enzymes. Iron which is not used for protein production is stored within tissues as ferritin or hemosiderin. If not enough iron is taken in from the diet, then the stored levels of iron will drop. If the stored levels become depleted, this can lead to iron deficiency anaemia. On the other hand, absorption of too much iron can cause accumulation of iron stores in the tissues. This can cause damage to organs such as the heart, liver, and pancreas.
Total Iron Binding Capacity, or TIBC, measures the total capacity of your blood to bind and transport iron, and therefore reflects your body’s iron stores. TIBC correlates with the amount of the protein transferrin in your blood, available to bind iron.
Transferrin is a protein that attaches iron molecules and transports iron in the blood plasma. Transferrin is largely made in the liver and regulates your body’s iron absorption into the blood.
Ferritin is a blood protein which contains iron and is used to understand how much iron your body stores.
The number of sites on transferrin that are not already carrying iron is referred to as unsaturated iron binding capacity (UIBC). This number can be added to the serum iron to calculate the TIBC.
C-reactive protein (CRP) is measure to asses inflammation in the body. This can be used to identify infections or other medical conditions. Particularly the CRP high-sensitivity (HS) test can be used to evaluate the risk of developing coronary artery disease.