From the Guidelines
The approach to anemia workup should begin with a thorough history, physical examination, and complete blood count with differential, and iron deficiency should be confirmed by iron studies prior to investigation, as recommended by the British Society of Gastroenterology guidelines 1. The initial laboratory evaluation should include reticulocyte count, peripheral blood smear, iron studies (serum iron, total iron binding capacity, ferritin), vitamin B12, folate levels, and renal function tests.
- Based on these results, anemia can be classified as microcytic (MCV <80 fL), normocytic (MCV 80-100 fL), or macrocytic (MCV >100 fL), which helps narrow the differential diagnosis.
- For microcytic anemia, consider iron deficiency, thalassemia, anemia of chronic disease, or sideroblastic anemia, and iron deficiency anemia typically shows low ferritin (<30 ng/mL), low serum iron, high TIBC, and low transferrin saturation, as noted in the guidelines 1.
- Normocytic anemia may indicate acute blood loss, hemolysis, anemia of chronic disease, or early nutritional deficiency, and a reticulocyte count helps distinguish between hypoproliferative causes (low reticulocytes) and blood loss or hemolysis (high reticulocytes) 1.
- For suspected hemolysis, order LDH, haptoglobin, and direct Coombs test, and macrocytic anemia suggests vitamin B12 or folate deficiency, alcoholism, liver disease, or myelodysplastic syndrome.
- Additional testing may include hemoglobin electrophoresis for suspected hemoglobinopathies, bone marrow examination for unexplained cytopenias, and specific tests for inherited disorders, as recommended by various guidelines 1. A good response to iron therapy (Hb rise ≥10 g/L within a 2-week timeframe) in anaemic patients is highly suggestive of absolute iron deficiency, even if the results of iron studies are equivocal, as stated in the British Society of Gastroenterology guidelines 1.
From the FDA Drug Label
Correct or exclude other causes of anemia (e. g., vitamin deficiency, metabolic or chronic inflammatory conditions, bleeding, etc.) before initiating PROCRIT. Evaluate the iron status in all patients before and during treatment. Monitor hemoglobin weekly until the hemoglobin level is stable and sufficient to minimize the need for RBC transfusion
The approach to the workup of anemia includes:
- Correcting or excluding other causes of anemia, such as vitamin deficiency, metabolic or chronic inflammatory conditions, bleeding, etc.
- Evaluating iron status in all patients before and during treatment
- Monitoring hemoglobin levels weekly until the hemoglobin level is stable and sufficient to minimize the need for RBC transfusion 2
From the Research
Approach to Anemia Workup
The approach to the workup of anemia involves a stepwise evaluation of the patient's condition, starting with a complete blood count (CBC) and reticulocyte count (RC), as well as peripheral smear evaluation 3. The differential diagnosis of anemia can be substantially narrowed by subcategorization into "microcytic," "normocytic," and "macrocytic" subtypes on the basis of mean corpuscular volume 4.
Laboratory Investigation
Laboratory investigation should include:
- Complete blood count (CBC) 3
- Reticulocyte count (RC) 3
- Peripheral smear evaluation 3
- Iron parameters and hemoglobinopathies/thalassemia evaluation in microcytic hypochromic anemia 3
- Vitamin B12 and folic acid level in macrocytic anemia 3
- Mean cell volume (MCV), red blood cell distribution width (RDW), hypochromic and microcytic erythrocytes, immature reticulocyte fraction (IRF), and some reticulocyte indices such as reticulocyte hemoglobin content and mean reticulocyte volume 5
Diagnostic Algorithms
Practical diagnostic algorithms can be used to address the differential diagnosis of anemia, based on traditional and new erythroid parameters 5. These algorithms consider three patterns: microcytic, normocytic, and macrocytic, and evaluate bone marrow erythropoiesis using reticulocyte count and IRF.
Treatment
Treatment of anemia depends on the underlying cause, and may include: