From the Guidelines
For a patient with new normocytic normochromic anemia, initial laboratory evaluation should include a complete blood count (CBC) with differential, reticulocyte count, comprehensive metabolic panel, iron studies (serum iron, total iron binding capacity, ferritin), vitamin B12 and folate levels, and inflammatory markers such as C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR). The most recent and highest quality study 1 provides guidance on the diagnosis and treatment of multiple myeloma, which can sometimes present with normocytic normochromic anemia. Additional testing should include a peripheral blood smear examination, hemolysis studies (lactate dehydrogenase, haptoglobin, and direct Coombs test), and thyroid function tests. These tests help distinguish between blood loss, hemolysis, and decreased production as the cause of anemia. The reticulocyte count is particularly important as it indicates whether the bone marrow is responding appropriately to the anemia. A low reticulocyte count suggests bone marrow dysfunction or nutritional deficiency, while an elevated count points toward blood loss or hemolysis. In some cases, further specialized testing may be needed based on initial results, including bone marrow examination if myelodysplastic syndrome or other bone marrow disorders are suspected, as suggested by 1. This comprehensive approach allows for accurate diagnosis and appropriate treatment of the underlying cause of the normocytic normochromic anemia. Key laboratory parameters to consider include ferritin, transferrin and transferrin saturation, reticulocyte counts, vitamin B12 and folate concentrations, haptoglobin, and creatinine levels, as outlined in 1. It is also important to consider the patient's overall clinical presentation and medical history when interpreting laboratory results and determining the need for further testing or referral to a specialist. In general, a thorough and systematic approach to the evaluation of normocytic normochromic anemia is essential to ensure that the underlying cause is identified and treated appropriately, as emphasized by 1.
From the Research
Laboratory Evaluation of Normocytic Normochromic Anemia
The following labs are indicated for a patient with new normocytic normochromic anemia:
- Complete blood count (CBC) to confirm the diagnosis of anemia and determine the mean corpuscular volume (MCV) 2
- Reticulocyte count to determine bone marrow function and differentiate between hypoproliferative and hyperproliferative anemias 2, 3
- Peripheral blood smear to examine the morphology of red blood cells and detect any abnormalities 2, 3
- Serum iron level, total iron-binding capacity, and serum ferritin level to rule out iron deficiency anemia 2
- Erythropoietin (EPO) level to evaluate for inadequate EPO production, particularly in patients with chronic renal failure 4
- Renal function tests, such as glomerular filtration rate (GFR), to evaluate for chronic renal failure as a cause of anemia 4
- Thyroid function tests to rule out hypothyroidism as a cause of anemia 3
- Vitamin B12 and folate levels to rule out deficiency as a cause of anemia 3
- Hemoglobin electrophoresis to rule out hemoglobinopathies as a cause of anemia 2, 3
- Bone marrow examination, although rarely necessary, may be considered in patients with unexplained normocytic normochromic anemia 5