What is the best course of action for managing iron deficiency anemia in a patient with ulcerative colitis, currently on prednisone, with an iron score of 160 and a ferritin score of 55?

Management of Iron Deficiency in Ulcerative Colitis with Serum Iron 160 and Ferritin 55

This patient has iron deficiency requiring iron supplementation, as the ferritin of 55 μg/L falls below the diagnostic threshold of 100 μg/L for iron deficiency in the presence of inflammation from ulcerative colitis. 1

Understanding the Laboratory Values in Context

The interpretation of these iron studies is fundamentally different in ulcerative colitis compared to healthy individuals due to the inflammatory state:

• Ferritin 55 μg/L indicates iron deficiency in this inflammatory context, even though it would be considered "normal" in a non-inflamed patient 1, 2
• In patients with ulcerative colitis or other inflammatory conditions, ferritin levels up to 100 μg/L may still represent true iron deficiency because ferritin is an acute-phase reactant that becomes artificially elevated during inflammation 1
• The serum iron of 160 mg/dL (assuming this is the unit) does not exclude iron deficiency, as serum iron levels fluctuate and are unreliable in inflammatory states 1

Diagnostic Confirmation Steps

Before initiating treatment, obtain these additional tests to fully characterize the anemia:

• Transferrin saturation (TSAT): A level <16% confirms iron deficiency even in the presence of inflammation 1
• C-reactive protein (CRP) and ESR: These confirm active inflammation and validate the adjusted ferritin interpretation threshold 1
• Complete blood count with MCV and RDW: To assess severity and rule out mixed deficiencies 1
• Soluble transferrin receptor (sTfR) if available: This is the most reliable test in inflammatory states—elevated in iron deficiency, normal or low in pure anemia of chronic disease 1, 2

Classification of Anemia Type

Based on ferritin 55 μg/L in an inflammatory context:

• This represents either pure iron deficiency or mixed anemia (combination of iron deficiency and anemia of chronic disease), as ferritin between 30-100 μg/L in the presence of inflammation suggests both conditions may coexist 1, 2
• If TSAT is <16%, this strongly supports the iron deficiency component 1

Treatment Approach

Iron supplementation should be initiated immediately once iron deficiency anemia is confirmed in ulcerative colitis patients 1:

First-Line Treatment Strategy

• Treat the underlying ulcerative colitis inflammation first, as this is the primary driver of anemia and will improve response to iron therapy 1
• The patient is already on prednisone, which should help control inflammation 3

Iron Supplementation Options

For mild anemia (Hb >10 g/dL):

• Oral iron supplementation with 100 mg/day iron sulfate is appropriate 1
• Consider every-other-day dosing rather than daily, as this improves absorption and reduces side effects 4

Critical caveat about oral iron in ulcerative colitis:

• More than 90% of ingested iron remains unabsorbed and may generate reactive oxygen species that can potentially exacerbate IBD 1
• Gastrointestinal side effects (nausea, flatulence, diarrhea) are common and lead to poor compliance 1, 4
• Proton pump inhibitors and H2-blockers impair oral iron absorption 1

For moderate-to-severe anemia or oral iron intolerance:

• Intravenous iron is preferred and should not be considered a last resort 1
• IV iron is more effective when inflammation and elevated hepcidin impair intestinal iron absorption 1
• Available IV formulations include iron sucrose (maximum 200 mg per dose), ferric carboxymaltose, ferumoxytol, and low molecular weight iron dextran 1
• Modern IV iron preparations have low rates of hypersensitivity (<1%) 4

Monitoring and Follow-Up

• Evaluate response to oral iron in 2-4 weeks: Expect a 1-2 g/dL increase in hemoglobin 4, 5
• If no response to oral iron, switch to IV iron rather than continuing ineffective oral therapy 1
• Long-term monitoring is essential: Recurrence of anemia occurs in >50% of patients after 1 year, often indicating ongoing intestinal inflammation 1
• Monitor patients in remission every 12 months and those with mild disease every 6 months 1

Additional Considerations

• Rule out other causes: Check vitamin B12 and folate levels, especially if macrocytosis is present 1
• Consider drug-induced anemia from sulfasalazine, thiopurines, or methotrexate if the patient is on these medications 1
• Avoid intramuscular iron supplementation due to lack of efficacy and adverse effects 1