From the Guidelines
Iron deficiency anemia is the most likely diagnosis given the blood smear findings of 2+ anisocytosis, 2+ hypochromasia, and 1+ poikilocytosis, and I recommend a complete blood count with iron studies, including serum ferritin, to confirm the diagnosis. The presence of hypochromasia and microcytosis, as indicated by the reduced mean cell Hb (MCH) and mean cell volume (MCV), are key markers of iron deficiency anemia 1. However, it's essential to note that these markers can also be affected by other conditions such as thalassemia, chronic disease, or vitamin B12/folate deficiency.
Given the specificity of serum ferritin (SF) for iron deficiency, an SF level of <15 μg/L is highly specific for iron deficiency, while a cut-off of 45 μg/L provides a respectable specificity of 0.92 1. If the iron studies confirm iron deficiency, oral iron supplementation such as ferrous sulfate 325mg taken once or twice daily between meals with vitamin C to enhance absorption would be an appropriate treatment. It's crucial to continue treatment for 3-6 months to replenish iron stores.
Other potential causes of these blood smear findings, such as thalassemia or chronic disease anemia, should be considered if iron studies are inconclusive. Patients should be evaluated for sources of blood loss, particularly gastrointestinal bleeding, heavy menstrual periods, or other chronic bleeding, and dietary counseling to increase iron-rich foods would be beneficial as an adjunct to supplementation. Hb electrophoresis may be recommended in those with microcytosis and normal iron studies, particularly if there is an appropriate ethnic background 1.
From the Research
Blood Smear Results
The given blood smear results show:
- 2+ anisocytosis, indicating a moderate variation in red blood cell size
- 2+ hypochromasia, indicating a moderate decrease in red blood cell hemoglobin
- 1+ poikilocytosis, indicating a mild variation in red blood cell shape
Possible Causes
Based on the studies, the following possible causes can be considered:
- Iron deficiency anemia, as it is a common cause of microcytic anemia and can lead to anisocytosis and hypochromasia 2, 3
- Beta-thalassaemia trait, as it can also cause microcytic anemia and changes in red blood cell parameters 4
Diagnostic Approach
To differentiate between iron deficiency anemia and beta-thalassaemia trait, the following tests can be used:
- Measurement of serum ferritin, iron concentration, transferrin saturation, and iron-binding capacity 2
- Calculation of the % microcytic/% hypochromic ratio, as it has been shown to be effective in distinguishing between the two conditions 4
- Mentzer index, which is currently used in some laboratories to differentiate between iron deficiency anemia and beta-thalassaemia trait 4
Other Considerations
It is worth noting that other factors, such as chronic disease, thalassemia, and sideroblastic anemia, can also cause microcytic anemia and changes in red blood cell parameters 2. However, the study on tobacco antigens and coronary artery disease does not appear to be relevant to the given blood smear results 5.