Review Question - QID 108140

This patient's presentation is most consistent with anemia of chronic disease secondary to his longstanding history of arthritis.

Anemia of chronic disease is caused by states of chronic inflammation that can result from a variety of inflammatory processes. Among the most common of these etiologies are cancer and arthritis. The diversity of other possible causes makes anemia of chronic disease the most common anemia in the hospital. The mechanism of anemia due to inflammation is that inflammation causes increased circulation of acute phase proteins such as hepcidin. Hepcidin then inhibits the release of iron from body stores despite a high level of total body ferritin in macrophages. This leads to a state of "effective iron deficiency".

The first thing to notice in this question is that fatigue, pale appearance, conjunctival pallor, and koilonychia are all signs of anemia. Anemia is then classically divided by MCV, which is found to be mildly microcytic in this scenario. Microcytic anemias can often be distinguished by peripheral blood smear showing target cells for thalassemias and sideroblasts for lead poisoning anemia. The two major causes of microcytic anemia that can result in a normal appearing erythrocytes are iron deficiency anemia and anemia of chronic disease. In BOTH cases the serum iron will be low, but iron deficiency anemia will have a low ferritin whereas anemia of chronic disease will have a high ferritin. The classic association of arthritis helps to confirm this diagnosis.

Incorrect Answers:
1 and 3: Thalassemias are genetically inherited diseases in the globin chains of hemoglobin. They often present in childhood and the severity of presentation depends on the degree of globin gene deletion or mutation. The classic cell is a target cell on peripheral blood smear.
Answer 4: Iron deficiency anemia can present very similarly but is associated with a decreased level of ferritin. There is also no history of bleeding or dietary deficiency in this case to suggest this diagnosis.
Answer 5: Lead poisoning anemia typically presents in children who live in old houses and adults who work in chemical industries. This is also associated with increased ferritin and decreased iron but would present with sideroblasts and lead lines on radiographs.

Anemia of chronic disease reaches a prevalence of almost 10% in chronically ill patients in nursing homes and therefore should be considered for any unknown cause of altered mental status or fatigue. Importantly the differential in these patients needs to include vitamin deficiency anemias and anemia due to kidney failure and lack of erythropoeitin production. Treatment is difficult and the best approach is to attempt rectification of the underlying disorder. (1)