Using Soluble Transferrin Receptor and Taking Inflammation into Account When Defining Serum Ferritin Cutoffs Improved the Diagnosis of Iron Deficiency in a Group of Canadian Preschool Inuit Children from Nunavik

Table 1

Diagnostic criteria defining iron depletion, IDE, and IDA based on traditional indicators of iron status and CRP.

	Traditional indicators of iron status and CRP
	Hb (g/L)	CRP (mg/L)	SF (µg/L)	TIBC (µmol/L)	and/or^†	TS
SF cutoff < 15 µg/L regardless of CRP level
Iron depletion^†	—	—	<15	—		—
IDE	—	—	<15	>72	or	<16
IDA	<110	—	<15	>72	or	<16
SF cutoffs < 15 or <50 µg/L w/o or w/ inflammation, respectively^‡
Iron depletion w/o inflammation	—	≤5	<15	—		—
Iron depletion w/ inflammation	—	>5	<50	—		—
IDE w/o inflammation	—	≤5	<15	>72	or	<16
IDE w/ inflammation	—	>5	<50	>72	or	<16
IDA w/o inflammation	<110	≤5	<15	>72	or	<16
IDA w/ inflammation	<110	>5	<50	>72	or	<16

IDE: iron deficient erythropoiesis; IDA: iron deficiency anemia; CRP: C-reactive protein; Hb: hemoglobin; SF: serum ferritin; TIBC: total iron binding capacity; TS: transferrin saturation; w/o: without; w/: with.
Reference sources for the cutoffs were as follows: Hb [19]; CRP [7, 31–33]; SF [6, 30]; TIBC [22, 23]; TS [14, 19, 23].
^†The choice “and/or” applies to the last two biochemical parameters.
^‡SF cutoffs were adjusted for inflammation using the C-reactive protein (CRP): w/o inflammation: CRP < 5 mg/L; w/ inflammation: CRP ≥ 5 mg/L.
Without or with concomitant IDE and IDA.