Transferrin & Iron Binding Capacity - TIBC:
Why Transferrin & Iron Binding Capacity - TIBC Test?
CLINICAL INFORMATION
Iron is vital for healthy muscles, bone marrow, organ functions, transportation of oxygen in RBCs (Iron in the haemoglobin has the affinity for oxygen and hence it binds to it), and in the Mitochondrial Electron Transport Chain (ETC), for the electron transport within cells (it thus helps the cells to generate energy). Iron has a major role in the growth and development, normal metabolism, synthesis of DNA, hormones, Reticulo-Endothelial (RES) System within the immune system (ferritin, hemosiderin) etc. The most important aspect in iron is that it has one-way metabolism. Hence when these normal iron levels when gets increased or decreased, these altered levels can lead to associated disorders. Clinical manifestations of low (iron) ferritin include dizziness, irritability, pica (craving for chalk, dust, soil etc), pallor (paleness / pale skin), chronic headaches, shortness of breath, rapid heartbeat, anaemia, fatigue or tiredness (loss of energy), hair loss, fibromyalgia, hypothyroidism, IBD, anxiety, depression and also certain cancers (are associated with low ferritin levels). When this condition is neglected, in chronic stages it leads to complications like it causes symptoms of chest pain, tinnitus (ringing sensation like whoosing or pounding sound in the ears), leg pain (restless legs syndrome) etc. Both the transferrin test and TIBC tests directly help to diagnose chronic iron overload and/or deficiency in the body. Moreover, this test indirectly measures the iron levels in the body by estimating the carrier proteins’ levels that involve in iron transport (i.e ability to transport iron in the blood). Transferrin is encoded by the TF gene (located in chromosome band 3q21). Transferrin is an iron carrier protein that transports iron. The iron-transferrin complex binds to its transferrin receptor on the cell surface such as erythroid precursors in the bone marrow. Iron is then released into the cell by vesicle (H+ATPases) through receptor-mediated endocytosis. Thus the bone marrow helps in the synthesis of RBCs, Hemoglobin – which helps in oxygen transport. When transferrin is not bound to iron it is known as apo-transferrin. Transferrin is a blood-plasma glycoprotein synthesized by the liver that transports iron through the blood to various tissues such as the liver, spleen, bone marrow etc. Thus the serum transferrin level estimates iron deficiency (eg. iron deficiency anaemia – microcytic, hypochromic) and/or iron-overload disorder (eg. Excess iron can lead to hemochromatosis). Transferrin helps in the regulation of iron metabolism (homeostasis) by modulating the absorption of iron (from the ingested food through GIT) into the blood. Higher transferrin indicates iron deficiency anaemia and/or iron depletion in the body. Symptoms of low ferritin include fatigue, weakness, lack of energy, joint pain, abdominal pain, loss of sex drive, organ damage such as heart, liver etc. Low transferrin suggests the body is absorbing more than adequate iron levels required for the body (eg. excess intake of iron supplements, repeated blood transfusions etc). Clinical manifestation of high transferrin saturation includes fatigue, loss of energy, weight loss, joint pain, high blood glucose levels (diabetes mellitus), loss of libido, arthritis, enlarged liver, and pregnancy (due to increased demand). Transferrin test also aids in the diagnosis of abnormalities associated with it such as pregnancy, use of OCPs, increased expression of transferrin protein, transferrin-iron saturation i.e Transferrin saturation (%) = (serum iron level multiplied by 100%) / TIBC, TIBC in iron deficiencies etc. The absence of transferrin (a rare genetic disorder) results in an abnormal condition known as - a transferrinemia, which leads to anaemia and hemosiderosis (results in heart failure and other complications like damage caused to organs such as the heart, liver, brain, and endocrine glands due to excess deposition of iron). TIBC is a total iron-binding capacity test that reflects transferrin levels in the blood bound to iron. TIBC test measures the blood’s ability to attach to iron present in the body. Two types of iron-binding capacity include unsaturated iron-binding capacity UIBC(i.e how much transferrin is not yet bound to iron) and total iron-binding capacity –TIBC (i.e total amount of iron in the blood + UIBC). TIBC test is indicated in case of clinical manifestations of iron abnormalities (signs and symptoms i.e swollen tongue, pale skin, tiredness, feeling cold all the time, easily susceptible to diseases, joint pain, stomach pain etc). Moreover, TIBC is a part of an iron panel test apart from CBC, hematocrit, haemoglobin etc. TIBC test results can be affected by certain substances such as ACTH, OCPs, chloramphenicol, fluorides etc. Other supporting tests include the ferritin test. Ferritin is an acute phase (cytosolic protein) reactant and its level is increased in inflammation. Ferritin is a protein that stores iron in the cell. Ferritin is an Iron Storing Protein (it stores iron inside the cells – like RBCs) and releases it when the body is deprived of iron, while Transferrin is a protein which combines with ferritin to transport it (mainly to new RBCs). The ferritin (blood) test helps to estimate the iron (ferritin test indirectly measures iron levels in the blood) stored in the body.
Additional tests include serum iron levels like serum iron levels, Hb concentration, Hematocrit, ferritin, Unsaturated Iron-Binding Capacity – UIBC, transferrin saturation etc, Hb concentration, Hematocrit, Zinc Protophorphyrin, HFE Gene test (to confirm the presence of hereditary hemochromatosis) etc.
General Instructions:
Sample Requirement: Specimen - Blood sample collected from the vein (As per physician’s Advice).Test Preparation: None.
NOTE - Sample for specimen collections may vary based on the patient’s condition/cases according to the patient’s presenting complaints/signs or symptoms:
SPECIMEN REQUIREMENT (Special or Rare Cases) - As instructed and guided by Physician / Clinician / Pathologist / as per Laboratory’s requirements, according to procedures and protocols.
This Multi-Specialty Clinical Referral Laboratory RT DIAGNOSTICS provides precise and accurate tests with an extensive range of testing services to the medical centres to help in the diagnosis and identification of pathology in the test specimens for infectious diseases and also to evaluate the function of organ systems of the patient. It prevents further complications and helps to stabilize and restore health to near normalcy at the earliest without delay.
