Also found in: Acronyms.
TIBCTotal iron-binding capacity Lab medicine A quantitative measurement of transferrin's ability to transport iron; normally, ±33% of transferrin's binding sites–BS are occupied by iron; in iron deficiency, pregnancy and viral hepatitis, 15% of transferrin's BS are occupied, therefore transferrin's capacity to bind iron or TIBC is ↑; in iron-overload syndromes–eg, hemochromatosis, transferrin has few sites available to bind iron and thus the TIBC is ↓
Iron-Binding Capacity (Total), Transferrin, and Iron Saturation
SpecimenSerum (1 mL) collected in a gold-, red-, or red/gray-top tube.
|Test||Conventional Units||SI Units|
|(Conventional Units × 0.179)|
|TIBC||250–350 mcg/dL||45–63 micromol/L|
|(Conventional Units × 0.01)|
|Transferrin||215–380 mg/dL||2.15–3.8 g/L|
This procedure is contraindicated for
- Assist in the diagnosis of iron-deficiency anemia
- Differentiate between iron-deficiency anemia and anemia secondary to chronic disease
- Monitor hematological response to therapy during pregnancy and iron-deficiency anemias
- Provide support for diagnosis of hemochromatosis or diseases of iron metabolism and storage
- Acute liver disease
- Hypochromic (iron-deficiency) anemias (insufficient circulating iron levels to saturate binding sites)
- Late pregnancy
- Chronic infections (transferrin is a negative acute-phase reactant protein and during periods of inflammation will demonstrate decreased levels) Cirrhosis (transferrin is a negative acute-phase reactant protein and during periods of inflammation will demonstrate decreased levels) Hemochromatosis (occurs early in the disease as intestinal absorption of iron available for binding increases) Hemolytic anemias (transferrin becomes saturated, and the iron-binding capacity is significantly decreased) Neoplastic diseases (transferrin is a negative acute-phase reactant protein and during periods of inflammation will demonstrate decreased levels) Protein depletion (transferrin contributes to the total protein concentration and will reflect a decrease in protein depletion) Renal disease (transferrin is a negative acute-phase reactant protein and during periods of inflammation will demonstrate decreased levels) Sideroblastic anemias (transferrin becomes saturated, and the iron-binding capacity is significantly decreased) Thalassemia (transferrin becomes saturated, and the iron-binding capacity is significantly decreased)
- Drugs that may increase TIBC levels include mestranol and oral contraceptives.
- Drugs that may decrease TIBC levels include asparaginase, chloramphenicol, corticotropin, cortisone, and testosterone.
Nursing Implications and Procedure
- Positively identify the patient using at least two unique identifiers before providing care, treatment, or services.
- Patient Teaching: Inform the patient this test can assist in diagnosing anemia.
- Obtain a history of the patient’s complaints, including a list of known allergens, especially allergies or sensitivities to latex.
- Obtain a history of the patient’s hematopoietic system, symptoms, and results of previously performed laboratory tests and diagnostic and surgical procedures.
- Obtain a list of the patient’s current medications, including herbs, nutritional supplements, and nutraceuticals (see Effects of Natural Products on Laboratory Values online at DavisPlus).
- Review the procedure with the patient. Inform the patient that specimen collection takes approximately 5 to 10 min. Address concerns about pain and explain that there may be some discomfort during the venipuncture.
- Sensitivity to social and cultural issues, as well as concern for modesty, is important in providing psychological support before, during, and after the procedure.
- Note that there are no food, fluid, or medication restrictions unless by medical direction.
- Potential complications: N/A
- Avoid the use of equipment containing latex if the patient has a history of allergic reaction to latex.
- Instruct the patient to cooperate fully and to follow directions. Direct the patient to breathe normally and to avoid unnecessary movement.
- Observe standard precautions, and follow the general guidelines in Patient Preparation and Specimen Collection. Positively identify the patient, and label the appropriate specimen container with the corresponding patient demographics, initials of the person collecting the specimen, date, and time of collection. Perform a venipuncture.
- Remove the needle and apply direct pressure with dry gauze to stop bleeding. Observe/assess venipuncture site for bleeding or hematoma formation and secure gauze with adhesive bandage.
- Promptly transport the specimen to the laboratory for processing and analysis.
- Inform the patient that a report of the results will be made available to the requesting health-care provider (HCP), who will discuss the results with the patient.
- Reinforce information given by the patient’s HCP regarding further testing, treatment, or referral to another HCP. Answer any questions or address any concerns voiced by the patient or family.
- Depending on the results of this procedure, additional testing may be performed to evaluate or monitor progression of the disease process and determine the need for a change in therapy. Evaluate test results in relation to the patient’s symptoms and other tests performed.
- Related tests include biopsy bone marrow, biopsy liver, CBC, CBC RBC count, CBC RBC indices, CBC RBC morphology, CBC WBC count and differential, erythropoietin, ferritin, folate, FEP, gallium scan, hemosiderin, lead, porphyrins, reticulocyte count, and vitamin B12.
- Refer to the Hematopoietic System table at the end of the book for related tests by body system.
Patient discussion about TIBC
Q. My Iron/TIBC tests normal, Ferritin,Serum = 22. Range 22-322. What is the problem? Iron Bind. Cap. ug/dL 324 range 250 - 450 UIBC ug/dL 206 range 150 - 375 Iron, Serum ug/dL 118 range 40 - 155 Iron Saturation % 36 range 15 - 55 Biopsy = Prostate Cancer....PCA high = 10.2 PSA now 8.3 PSA Ultra W/Serial Monitor ...Ultrasenitive = 8.26