From the Guidelines
In the setting of severe autoimmune disease with low iron, low ferritin, and low total iron binding capacity (TIBC), intravenous iron supplementation is the most effective treatment approach, as it can bypass the inflammatory blockade of iron absorption and release from storage sites, and should be considered as first-line treatment. This is based on the most recent and highest quality study available, which concludes that IV iron is more effective, shows a faster response, and is better tolerated than oral iron 1.
Diagnosis and Treatment Approach
The patient's presentation is consistent with anemia of chronic inflammation (also called anemia of chronic disease), which is a common complication of severe autoimmune disease. The low iron, low ferritin, and low TIBC levels are characteristic of this condition, which is caused by the increased production of hepcidin and other inflammatory cytokines that block iron absorption and release from storage sites.
- The recommended approach is to treat the underlying autoimmune condition aggressively while simultaneously addressing the iron deficiency.
- Intravenous iron formulations like iron sucrose or ferric carboxymaltose may be necessary, with a typical IV iron course of 1000mg total, divided into multiple doses based on the specific formulation.
- Laboratory evaluation following IV iron should include a CBC and iron parameters (ferritin, percent transferrin saturation (TSAT) calculated by dividing the serum iron by the total iron binding capacity (TIBC)) 4 to 8 weeks after the last infusion, as recommended by the expert consensus guidelines 1.
- The goal ferritin is 50 ng/mL, regardless of sex at birth, and a TSAT <20% has high sensitivity for diagnosing absolute or functional iron deficiency.
Monitoring and Follow-up
- Monitor complete blood counts and iron studies every 1-3 months to assess the response to treatment and adjust the treatment plan as needed.
- The frequency with which lab monitoring is required post-IV iron infusion is dependent on the cause of the iron deficiency, and those with recurrent blood loss will require more frequent and aggressive laboratory monitoring to diagnose and treat iron deficiency even in the absence of anemia 1.
Rationale for Treatment Approach
The use of intravenous iron supplementation is supported by the most recent and highest quality study available, which concludes that IV iron is more effective, shows a faster response, and is better tolerated than oral iron 1. Additionally, the expert consensus guidelines recommend IV iron as the first-line treatment for patients with clinically active autoimmune disease, with previous intolerance to oral iron, with hemoglobin below 100 g/L, and in patients who need erythropoiesis-stimulating agents 1.
From the Research
Low Iron, Low Ferritin, and Low TIBC in Severe Autoimmune Disease
- Low iron, low ferritin, and low Total Iron-Binding Capacity (TIBC) can be indicative of iron deficiency anemia, which is common in patients with severe autoimmune diseases 2.
- In patients with chronic inflammatory conditions, such as autoimmune diseases, iron deficiency can be masked by inflammation, making diagnosis and treatment challenging 2.
- Ferric carboxymaltose (FCM) has been shown to be effective in treating iron-deficiency anemia in patients with various conditions, including those with gastrointestinal disorders 3, 4, 5.
- FCM has a favorable benefit-risk profile and is superior to oral iron or placebo in replenishing iron stores 3.
- The efficacy of FCM in correcting anemia is similar to that of iron sucrose, and it has a lower risk of hypersensitivity reactions compared to iron dextran 3, 5.
- In patients with severe autoimmune diseases, intravenous iron replacement options, such as FCM, may be beneficial in treating iron deficiency anemia 2, 4.
- It is essential to interpret diagnostic lab tests carefully to recognize patients who are most likely to benefit from iron supplementation and to choose between oral and parenteral administration 2.