Transferrin Level of 174 mg/dL: Interpretation and Management
A transferrin level of 174 mg/dL is within the normal range and does not require specific intervention, but must be interpreted alongside iron studies (ferritin, TSAT) and clinical context to determine iron status and nutritional adequacy.
Understanding the Result
Normal transferrin ranges typically fall between 200-360 mg/dL in most laboratories, though a level of 174 mg/dL may still be considered low-normal or mildly decreased depending on the reference range used 1
Transferrin is a negative acute-phase reactant, meaning it decreases during inflammation, infection, or malignancy, independent of iron status 1, 2
The level alone cannot determine iron deficiency or adequacy—you must calculate transferrin saturation (TSAT) using the formula: TSAT (%) = (serum iron / TIBC) × 100, where TIBC can be derived from transferrin using: TIBC (μmol/L) = Transferrin (g/L) × 25.1 3
Clinical Interpretation Algorithm
Step 1: Calculate TSAT and Check Ferritin
If TSAT <16-20% with ferritin <30 ng/mL: This indicates absolute iron deficiency requiring iron supplementation 3, 2
If TSAT <20% with ferritin 30-100 ng/mL: This suggests a combination of true iron deficiency and anemia of chronic disease 3
If TSAT <20% with ferritin >300 ng/mL: This indicates anemia of chronic inflammation, not iron deficiency—the low transferrin reflects inflammation, not nutritional depletion 2
If TSAT 20-50% with normal ferritin: Iron status is adequate; the mildly low transferrin may reflect inflammation or other non-iron factors 3
Step 2: Assess for Inflammatory Conditions
Check inflammatory markers (CRP, ESR) to determine if the transferrin level is suppressed by inflammation rather than reflecting true iron or nutritional status 2
In patients with chronic inflammatory conditions (inflammatory bowel disease, heart failure, chronic kidney disease), transferrin levels decrease as part of the acute-phase response, making it a poor marker of nutritional status in these populations 1, 2
Step 3: Consider Clinical Context
In chronic kidney disease patients on dialysis: Transferrin has limited utility due to confounding from chronic blood loss, erythropoietin therapy, and IV iron administration—serum albumin is preferred for nutritional assessment 1
In non-dialyzed CKD patients: Transferrin may be more useful for nutritional assessment when patients are not receiving erythropoietin or iron therapy 1
Avoid checking iron parameters within 4 weeks of IV iron administration, as circulating iron interferes with assays 3, 2
Common Pitfalls to Avoid
Do not assume low transferrin equals iron deficiency—in inflammatory states, ferritin rises while transferrin falls, masking true iron status 2
Do not rely on transferrin alone for nutritional assessment—it lacks specificity compared to serum albumin and prealbumin, particularly in patients with chronic disease 1
Do not ignore the clinical context—recent meals, diurnal variation, and inflammation all affect iron parameters and transferrin levels 3
Do not evaluate transferrin saturation without considering ferritin levels simultaneously, as this leads to missed diagnoses 3
Management Recommendations
If iron deficiency is confirmed (low TSAT, low ferritin): Initiate oral or IV iron supplementation based on severity and patient factors; recheck CBC and iron parameters 4-8 weeks after completing therapy 3
If anemia of chronic disease is present (low TSAT, high ferritin, elevated inflammatory markers): Address the underlying inflammatory condition rather than providing iron supplementation 2
If transferrin is low but iron studies are normal: No specific intervention for the transferrin level itself is needed—focus on treating any underlying inflammatory or chronic disease 1, 2
For nutritional assessment in chronic disease: Use serum albumin and prealbumin rather than transferrin, as they provide more specific information about protein-energy malnutrition 1