What happens in the body
During prolonged inflammation, immune cells release substances that trigger the production of the hormone hepcidin in the liver. It blocks the release of iron from intestinal cells and from macrophages, where iron is stored from destroyed red blood cells. The meaning of this reaction is protective: microbes also need iron to reproduce, and the body hides it. At the same time, inflammation shortens the life of red blood cells and dulls the response of the bone marrow to erythropoietin, a hormone that stimulates hematopoiesis. As a result, there is iron in the body, but it is not available for the formation of hemoglobin.
- Inflammation increases hepcidin levels
- Iron is blocked in the depot
- Absorption of iron in the intestine is reduced
- The lifespan of red blood cells is shortened
- Bone marrow responds less well to erythropoietin
What diseases does it occur in?
Anemia of inflammation accompanies conditions that last for months or years. These are rheumatoid arthritis, systemic lupus erythematosus and other autoimmune diseases, inflammatory bowel diseases, chronic infections, including tuberculosis and osteomyelitis, malignant tumors, chronic kidney disease, heart failure, obesity with chronic inflammation. In older people, it is often the first noticeable sign of an underlying problem, so anemia at this age is never attributed to age without examination.
- Rheumatoid arthritis and other autoimmune diseases
- Inflammatory bowel diseases
- Chronic infections, tuberculosis
- Malignant tumors
- Chronic kidney disease
- Heart failure
- Long-term suppurative processes
Symptoms
Since anemia develops gradually, the body has time to adapt, and complaints remain mild for a long time. Fatigue, decreased endurance, shortness of breath and palpitations during exertion, pallor, chilliness, and decreased concentration are typical. In people with heart disease, anemia increases angina and shortness of breath. An important feature: anemia of inflammation is not characterized by signs of severe iron deficiency - taste distortion, craving for chalk and ice, brittle nails and jamming. Their appearance rather indicates concomitant iron deficiency.
- Fatigue and weakness
- Shortness of breath and palpitations on exertion
- Pale skin and mucous membranes
- Decreased concentration
- Chilliness
- Worsening of heart disease
How to distinguish from iron deficiency anemia
The distinction is important because the treatment is different. With iron deficiency, the reserves are empty: ferritin is low, transferrin and total iron-binding capacity are increased, red blood cells are small and pale. In anemia of inflammation, serum iron is also reduced, but ferritin is normal or elevated, and transferrin is reduced; red blood cells are more often than normal size. The difficulty is that the conditions are often combined, especially with intestinal diseases and blood loss. Then the doctor focuses on additional indicators and assesses the level of inflammation using C-reactive protein.
- Ferritin: low with deficiency, normal or high with inflammation
- Transferrin: increased with deficiency, decreased with inflammation
- Red blood cell size is often normal in anemia of inflammation
- C-reactive protein helps assess inflammatory activity
- A combination of two conditions is possible
- If blood loss is suspected, the intestines are examined
Treatment
The main principle: the underlying disease needs to be treated, because as inflammation subsides, hemoglobin rises on its own. Iron supplements are prescribed only for proven concomitant deficiency, and in cases of severe inflammation, intravenous forms work better than tablets, which are almost not absorbed. In case of chronic kidney disease, drugs that stimulate hematopoiesis are used strictly under the supervision of a doctor. Blood transfusions are reserved for severe symptomatic cases. Taking iron “for prevention” with normal ferritin is useless and increases the load on the body.
- Controlling the underlying disease is the main step
- Iron supplements only for confirmed deficiency
- Intravenous iron for severe inflammation
- Erythropoiesis stimulants for kidney disease
- Blood transfusion according to strict indications
- Monitoring blood tests over time
