1.1. Patients and providers would be more worried about the underlying chronic condition as the secondary ACD would be mild in nature. If hemoglobin levels drop enough, then symptoms of iron deficiency anemia (IDA) develop and include fatigue, weakness, headache, irritability, exercise intolerance, exertional dyspnea, vertigo, and angina pectoris (Schrier, 2017).
2. Diagnostic tests
2.1. A pattern of abnormal findings of various labs would suggest ACD. Hemoglobin concentrations are typically 10-11g/dL, with the RBCs normal in shape and color. They would appear smaller and more pale less than 25% of the time, which is also when hemoglobin is around 8-9.5g/dL. In the more severe cases, which occur roughly 20% of the time, hemoglobin would fall under 8g/dL. Low serum sodium (Normal [N]: 60-150mcg/dL), normal to low serum transferrin (N: 300-360mcg/dL), Low transferrin saturation, normal to increased serum ferritin (N: 400-200ng/mL), elevated erythrocyte sedimentation rate (N: 0-20mm/hour in men, 0-30mm/hour in women), or elevated C-reactive protein (N: <3mg/L for most) (Schrier & Camaschella, 2017).
2.2. To differentiate between ACD and iron deficiency anemia (IDA), the levels of the transport protein of iron (transferrin) are increased in IDA, and reduced or normal in ACD due to the iron being trapped in the reticulo-endothelial system causing low serum iron, further causing lew transferrin saturation (Madu & Maduka, 2017).
3. Treatments
3.1. As ACD occurs secondary to a chronic condition, treatment would be aimed at fixing or at least better managing the chronic condition.
3.2. If ACD does become severe, RBC transfusions or the addition of an erythropoietic stimulating agent is warranted. Erythropoietin (EPO) can be given once a week to three times a week (depending on the dose), with high doses able to overcome the reduced response of bone marrow cells. Treatment is typically started when hemoglobin is <10g/dL and stopped when hemoglobin hits 12g/dL. Darbepoetin may also be used and works similarly to EPO. Due to Darbepoetin’s long half-life, and that this type of anemia is dealt with on a shorter term, EPO treatment is preferred. Supplemental Iron, IV or oral, may also be used to keep transferrin saturation above 20% and serum ferritin over 100ng/dL (Schrier & Camaschella, 2017).
4. Pathophysiologic etiology
4.1. AKA anemia of (chronic) inflammation, or hypoferremia of inflammation. A large number of conditions may cause Anemia of chronic disease (ACD), which are typically mild in nature as they cause the shortening of the life of red blood cell (RBC) survival. Such conditions “include infections, inflammatory disorders, malignancy, trauma, diabetes mellitus, aging, and acute or chronic immune activation” (Schrier & Camaschella, 2017).
4.2. Certain conditions may cause a decrease in RBC lifespan, suppression of erythropoietin production, decreased response to erythropoietin by cells in bone marrow, or a change in how iron is metabolized or stored in macrophages (McCance & Huether, 2014, p. 1001).
5. Inflammation
5.1. May cause the release of cytokines including interleukins (IL) 1 and 6 as well as tumor necrosis factor (TNF) alpha. These in turn activate TNF-gamma, TNF-beta, and T lymphocytes as well as a cascade of other cell communicators, many of which are involved in clotting. For example, IL-1 and TNF-alpha may induce apoptosis of red blood cells and downregulate erythropoietin receptors. Erythropoietin normally would promote red blood cell formation (Schrier & Camaschella, 2017).
6. Causative factors
6.1. Having conditions that affect any part of the cycle of red blood cell formation and lifespan or its hormones. Another example would be rheumatoid arthritis, which has an inflammatory component that would cause ACD. If treated with an anti-TNF-alpha antibody, then the IL-6 levels also decrease, leading to an improvement in the anemia symptoms. If the chronic condition is not severe enough to affect RBCs or erythropoietin and its receptors, then this type of anemia would not present (Schrier & Camaschella, 2017).
7. Risk factors
7.1. Same as the risk factors for the various chronic conditions that cause ACD (Schrier & Camaschella, 2017).
