From the Guidelines
The most recent complete blood count (CBC) test results are not provided, but based on the available evidence, a comprehensive evaluation of anemia should include a morphologic approach, characterizing anemia based on the mean corpuscular volume (MCV), and a kinetic approach, focusing on the underlying mechanism of anemia 1.
Key Parameters to Evaluate
When evaluating CBC test results, the following key parameters should be considered:
- White blood cell count (WBC)
- Red blood cell count (RBC)
- Hemoglobin
- Hematocrit
- Platelet count
- Differential counts (neutrophils, lymphocytes, monocytes, eosinophils)
Approach to Evaluation
A complete evaluation of anemia often uses both morphologic and kinetic approaches 1. The morphologic approach characterizes anemia based on the MCV, which can indicate:
- Microcytic (< 80 fL): iron deficiency, thalassemia, anemia of chronic disease, or sideroblastic anemia
- Normocytic (80–100 fL): hemorrhage, hemolysis, bone marrow failure, anemia of chronic inflammation, or renal insufficiency
- Macrocytic (> 100 fL): vitamin B12 or folate deficiency, alcoholism, myelodysplastic syndrome (MDS), or certain drugs The kinetic approach focuses on the underlying mechanism of anemia, distinguishing among the production, destruction, and loss of RBCs, using the reticulocyte count corrected against the degree of anemia (reticulocyte index [RI]) 1.
Importance of Regular Follow-up
Regular follow-up testing should continue as recommended by the healthcare provider to ensure continued monitoring of these values, as any cause of anemia that may be rectified independent of cancer therapy should be treated as indicated 1.
Considerations for Anemia Evaluation
When evaluating anemia, it is essential to consider the patient's medical history, physical examination, and laboratory results, including the CBC test results, to determine the underlying cause of anemia and guide treatment decisions, as abnormalities in two or more cell lines should be evaluated carefully and likely warrant discussion with a hematologist 1.
From the Research
Results of Complete Blood Count (CBC) Tests
The results of CBC tests can vary due to several factors, including:
- Preanalytical variation, biological variation, and analytical variation 2
- Intraindividual biologic variation, which can be more common than laboratory error 3
- Age-associated physiologic changes, which can alter laboratory values in the elderly without constituting a pathologic process 3
Factors Affecting CBC Results
The following factors can affect CBC results:
- State of health of an individual, even if it remains the same 2
- Time of sample measurement, which can result in different outcomes even at the same clinical laboratory 2
- Type of clinical laboratory used, which can lead to variations in results 2
Interpretation of CBC Results
When interpreting CBC results, it is essential to consider:
- The functions and diseases of red and white blood cells, which can aid in diagnosis of various conditions 4
- The potential for unexpected results, which may not always indicate laboratory error or a change in the patient's clinical status 3
- The dynamics of white blood cell and platelet populations, which can define human inflammatory recovery 5
- The hematologic manifestations of systemic disease, which can affect CBC results 6