Iron studies

Test	What it measures	Finding in iron deficiency	Finding in iron overload
Standard iron studies panel
Serum iron	Iron in the circulation Can be transiently elevated after taking an iron supplement (including multivitamin with iron) or iron-rich meal Only used to calculate transferrin saturation (TSAT); not useful in isolation	Not used for diagnosis	Not used for diagnosis
Transferrin or TIBC	Iron binding proteins Upregulated when iron stores are low	High (refer to the laboratory reference range)	Low (refer to the laboratory reference range)
Transferrin saturation (TSAT)	Percent of iron binding proteins saturated with iron Calculated from serum iron and TIBC Helpful in individuals with inflammation that may elevate the ferritin	Low (cutoffs vary) ≤19% is often used	High >45%
Ferritin	Iron storage protein Acute phase reactant; increased in inflammatory states, which can mask iron deficiency Unaffected by recent iron intake	Low (cutoffs vary) <30 ng/mL is often used	High Female: >200 ng/mL Male: >300 ng/mL
Specialized testing for selected cases
Soluble transferrin receptor (sTfR) or sTfR-ferritin index	sTfR circulates after being cleaved from cells sTfR is upregulated when iron stores are low	sTfR-ferritin index >2	Not used for diagnosis
Reticulocyte hemoglobin content (CHr)	Hemoglobin in reticulocytes Not increased in inflammatory states Often used in CKD Unreliable in thalassemia	<29 pg	Not used for diagnosis
Bone marrow iron stain	Storage iron (gold standard test)	Absent	Increased

Iron studies test for iron deficiency. Ferritin alone is a reasonable first test for individuals without comorbidities; a low ferritin is diagnostic of iron deficiency. A full iron studies panel may be used if there are acute or chronic inflammatory conditions that might increase the ferritin or if having to return for additional testing would confer a significant burden. Some experts suggest fasting prior to a full iron studies panel to avoid interference with the serum iron level. A ferritin <30 ng/mL and/or TSAT ≤19% have a 98% sensitivity and 92% specificity for absent bone marrow iron.

CKD: chronic kidney disease; TIBC: total iron binding capacity.

Graphic 143088 Version 1.0

خرید پکیج

Iron studies