Anemia of chronic disease is a normochromic, normocytic anemia caused by a diverse set of chronic diseases that include neoplastic, infectious, inflammatory, endocrine, metabolic, and end organ–related conditions, such as kidney failure. The most common causes are chronic infections, kidney disease, liver disease, autoimmune conditions, and malignancy.
Anemia of chronic disease is characterized by changes in iron metabolism, including decreased serum iron levels, decreased transferrin levels, decreased transferrin saturation, and normal to increased ferritin levels (reflex test in microcytic and normocytic anemia with abnormal CBC).1 Treatment of the underlying disease generally improves this type of anemia. Therefore, further evaluation should be focused on determining the identity of the underlying disease, if not already known. Often, history, physical, and laboratory results may suggest areas to investigate. For example, findings of normocytic anemia on a comprehensive metabolic panel may suggest liver disease, diabetes, or kidney disease. Review of the white blood cell count and differential may suggest an inflammatory condition or hematopoietic neoplasm.
For microcytic anemia, an unremarkable hemoglobinopathy evaluation combined with an in-range or low reticulocyte count suggests anemia of chronic disease (<25% of cases are microcytic).2 For macrocytic anemia with in-range or low reticulocyte count, high folate or B12 results reflex to liver function tests. Elevated liver enzyme levels distinguish chronic liver disease from hematologic diseases (eg, myelodysplasia).3,4