Transferrin saturation (TS), measured as a percentage, is a

medical Medicine is the science and practice of caring for a patient, managing the diagnosis, prognosis, prevention, treatment, palliation of their injury or disease, and promoting their health. Medicine encompasses a variety of health care practic ...

laboratory value. It is the value of

serum iron Serum iron is a medical laboratory test that measures the amount of circulating iron that is bound to transferrin (90%) and serum ferritin (10%). Clinicians order this laboratory test when they are concerned about iron deficiency, which can cause ...

divided by the

total iron-binding capacity Total iron-binding capacity (TIBC) or sometimes transferrin iron-binding capacity is a medical laboratory test that measures the blood's capacity to bind iron with transferrin. Transferrin can bind two atoms of ferric iron (Fe3+) with high affinit ...

of the available

transferrin Transferrins are glycoproteins found in vertebrates which bind to and consequently mediate the transport of iron (Fe) through blood plasma. They are produced in the liver and contain binding sites for two Fe3+ ions. Human transferrin is encode ...

, the main protein that binds iron in the blood, this value tells a clinician how much serum iron is bound. For instance, a value of 15% means that 15% of iron-binding sites of transferrin are being occupied by iron. The three results are usually reported together. A low transferrin saturation is a common indicator of

iron deficiency anemia Iron-deficiency anemia is anemia caused by a lack of iron. Anemia is defined as a decrease in the number of red blood cells or the amount of hemoglobin in the blood. When onset is slow, symptoms are often vague such as feeling tired, weak, s ...

whereas a high transferrin saturation may indicate

iron overload Iron overload or hemochromatosis (also spelled ''haemochromatosis'' in British English) indicates increased total accumulation of iron in the body from any cause and resulting organ damage. The most important causes are hereditary haemochromatosi ...

hemochromatosis Iron overload or hemochromatosis (also spelled ''haemochromatosis'' in British English) indicates increased total accumulation of iron in the body from any cause and resulting organ damage. The most important causes are hereditary haemochromatosi ...

. Transferrin saturation is also called transferrin saturation index (TSI) or transferrin saturation percentage (TS%) __TOC__

Interpretation

Studies also reveal that a transferrin saturation (serum iron concentration ÷ total iron binding capacity) over 60 percent in men and over 50 percent in women identified the presence of an abnormality in iron metabolism (Hereditary hemochromatosis, heterozygotes and homozygotes) with approximately 95 percent accuracy. This finding helps in the early diagnosis of Hereditary hemochromatosis, especially while serum

ferritin Ferritin is a universal intracellular protein that stores iron and releases it in a controlled fashion. The protein is produced by almost all living organisms, including archaea, bacteria, algae, higher plants, and animals. It is the primary ' ...

still remains low. The retained iron in Hereditary hemochromatosis is primarily deposited in parenchymal cells, with reticuloendothelial cell accumulation occurring very late in the disease. This is in contrast to transfusional iron overload in which iron deposition occurs first in the reticuloendothelial cells and then in parenchymal cells. This explains why ferritin levels remain relative low in Hereditary hemochromatosis, while transferrin saturation is high.

Usual values

Normal

reference range In medicine and health-related fields, a reference range or reference interval is the range or the interval of values that is deemed normal for a physiological measurement in healthy persons (for example, the amount of creatinine in the blood, or ...

s are: * Serum iron: 60–170 μg/dL (10–30 μmol/L) * Total iron-binding capacity: 240–450 μg/dL * Transferrin saturation: average 25%. Reference ranges depend on multiple factors like age, sex,

race Race, RACE or "The Race" may refer to: * Race (biology), an informal taxonomic classification within a species, generally within a sub-species * Race (human categorization), classification of humans into groups based on physical traits, and/or s ...

and test devices. Most laboratories define “normal” as max. 30% for female and max. 45% for male persons. Above 50% the risk of toxic non-transferrin bound iron (NTBI) rises exponentially, potentially causing organ damage.Meghna Patel et al.: Non Transferrin Bound Iron: Nature, Manifestations and Analytical Approaches for Estimation. Ind J Clin Biochem (Oct-Dec 2012) 27(4):322–332 DOI 10.1007/s12291-012-0250-7 μg/dL = micrograms per deciliter μmol/L = micromoles per liter Laboratories often use different units and "normal" may vary by population and the lab techniques used. To help clinicians interpret their patients' results, laboratories are generally also required to report their normal or

reference values In medicine and health-related fields, a reference range or reference interval is the range or the interval of values that is deemed normal for a physiological measurement in healthy persons (for example, the amount of creatinine in the blood, o ...

Blood values sorted by mass and molar concentration

References

{{DEFAULTSORT:Transferrin Saturation Blood tests Iron metabolism Transferrins