Anemia of chronic disease: Causes, Symptoms, Diagnosis and Treatment
Anemia of chronic disease is a type of anemia that occurs alongside a longstanding disease or inflammation. It starts as normocytic and as time passed it becomes microcytic hypochromic anemia. In this article we will delve into its symptoms, causes, and treatment.
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◉ What is Anemia of Chronic Disease
Anemia of chronic disease, also know as anemia of inflammation, occurs when there's an autoimmune illness or any other chronic illness that lasts over three months and causes long standing inflammation.
Anemia of chronic inflammation is a response to the body dealing with persistent inflammation. Chronic inflammation affects the body's ability to utilize the iron needed to make adequate amount of red blood cells, impairing their function and causing anemia.
Treatment of anemia of chronic disease automatically happens by treating the underlying condition. Sometimes erythropoietin is administered to accelerate the treatment process.
◉ Pathophysiology
This type of anemia occurs as part of a chronic inflammatory disorder, a process that can begin during infection, inflammation, trauma, critical illness, or after surgery.
Here are four pathophysiological mechanisms known to be the cause:
- Increased hemophagocytosis by macrophages leads to shortened half-life of RBCs in patients with inflammatory diseases.
- Decrease in both erythropoietin production and marrow responsiveness and sensitivity to erythropoietin leads to impairment in erythropoiesis.
- Inflammatory cytokines can impair red blood cell proliferation and differentiation in bone marrow through radical formation, and induction of apoptosis.
- Changes in iron metabolism as a result of an increase in hepcidin, which inhibits iron absorption, and leads to iron sequestration.
◉ Causes
Many diseases can cause anemia of chronic disease, here is a list of some of them:
- Cancer.
- Chronic renal failure.
- Heart failure, whether congestive or restrictive.
- Autoimmune diseases such as: Rheumatoid arthritis, Systemic lupus erythematosus, Vasculitis
- Inflammatory bowel disease, such as Crohn's and ulcerative colitis
- Irritable bowel syndrome (IBS).
- Any type of chronic untreated infection.
◉ Symptoms and signs
The severity of symptoms may vary depending on the chronic disease involved and the degree of anemia.
- Symptoms of the chronic disease causing anemia as rheumatoid arthritis, chronic kidney disease or chronic inflammation.
- Feeling of weakness and tiredness.
- Skin color becomes pale.
- Increase sweating without reason.
- Dizziness and headache.
- Murmur angina may occur due to reduced cardiovascular performance.
- Shortness of breath with physical activity.
- Impaired learning and memory capacity.
- Cold hands and feet.
- Irregular heart rate.
It's essential to note that these symptoms are nonspecific and may be indicative of various health issues. Further examination and medical evaluation are necessary for an accurate diagnosis and appropriate management.
◉ Diagnosis and laboratory tests
The initial diagnosis is made by obtaining a thorough medical history from the patient, followed by general investigations to exclude other types of anemia.
It is crucial during the investigation to differentiate between anemia of chronic disease, iron deficiency anemia, and other causes of hypochromic and microcytic anemia.
◉ Laboratory findings in Anemia of Chronic Disease
- CBC blood test: moderate anemia with hemoglobin levels usually between 8 and 9.5gm/dl and decreased . MCV (Mean Corpuscular Volume) can be normal (normocytic anemia) or decreased (microcytic anemia).
- Reticulocyte count is decreased.
- Serum iron is decreased.
- Transferrin saturation is reduced due to a lack of iron and increased production of transferrin.
- Serum transferrin increased.
- Erythrocyte-free protoporphyrin is increased.
- Serum ferritin is increased because it's an acute-phase reactant that increases in case of inflammation.
- Total iron-binding capacity (TIBC) is decreased.
- Soluble transferrin receptors (sTFR) level is usually low in iron deficiency anemia compared to anemia of chronic disease.
- Hepcidin, serum hepcidin, is known as the most accurate serological marker that differentiates between anemia of chronic disease and iron deficiency anemia.
- Cytokine levels are increased
Blood film: it may provide information of underlying causes of anemia of chronic
disease for example it may show thrombocytosis in case of chronic hemorrhage, neutrophils containing toxic granules in sever sepsis or
hyper-segmented neutrophils in mixed nutritional deficiency or vitamin B12 deficiency/folate deficiency.
◉ Treatment
Main aim of treatment is treatment of underlying cause of anemia to relieve its symptoms. People who have anemia caused by cancer or chronic kidney disease or autoimmune disease may need additional treatment. The available treatment options are:
The treatment of anemia of chronic inflammation may include:
- Blood transfusion: it's an important choice for short term management option especially in patients with severe anemia associated with cardiac decompensation. But it’s not preferred for long term treatment as it associated with increased mortality due to iron overload and activation of immune system.
- Erythropoiesis-Stimulating Agents: as synthetic erythropoietin therapy this increase level erythropoietin hormone that help your bone marrow synthesize red blood cells.
- Hepcidin antagonists.
◉ Conclusion
Anemia of chronic disease happens due to longstanding infections, autoimmune conditions and malignancies as a result of numerous inflammatory factors such as hepcidin, and the main line of treatment is to primarily correct the underlying condition, but in severe cases red blood cell transfusions and erythropoietin injections can be given.
