From the Guidelines
These lab values indicate macrocytic anemia, likely due to vitamin B12 or folate deficiency, as suggested by the high MCV of 99 fL 1. The hemoglobin level of 14 g/dL is within the normal range, suggesting adequate oxygen-carrying capacity. The hematocrit of 41.2% is also normal, representing the percentage of blood volume occupied by red blood cells. The MCH (mean corpuscular hemoglobin) of 33.6 pg and MCHC (mean corpuscular hemoglobin concentration) of 34 g/dL are both normal, showing appropriate hemoglobin content within the red blood cells. The RDW (red cell distribution width) of 11% is normal, indicating uniform red blood cell size. However, the high MCV is a key indicator of macrocytosis, which can be caused by vitamin B12 or folate deficiency, as well as other factors such as thiopurine treatment, alcohol abuse, or hypothyroidism 1. The ferritin level of 67 ng/mL is within normal limits, suggesting adequate iron stores, which makes iron deficiency anemia less likely 1. Key points to consider in the diagnosis of anemia include:
- MCV and MCH to determine the size and hemoglobin content of red blood cells
- RDW to assess the uniformity of red blood cell size
- Ferritin level to evaluate iron stores
- Reticulocyte count to assess bone marrow response to anemia Further evaluation, including vitamin B12 and folate levels, may be necessary to determine the underlying cause of the macrocytosis 1.
From the Research
Lab Results Indication
The lab results provided are:
- Hemoglobin: 14
- Hematocrit: 41.2
- MCV (Mean Corpuscular Volume): 99
- MCH (Mean Corpuscular Hemoglobin): 33.6
- MCHC (Mean Corpuscular Hemoglobin Concentration): 34
- RDW (Red Cell Distribution Width): 11
- Ferritin: 67
Interpretation of Results
Based on the provided lab results, the MCV value is 99, which is close to but does not exceed 100 fL, the threshold for macrocytosis as defined by studies 2, 3. However, these studies suggest that macrocytosis is generally defined as an MCV greater than 100 fL.
Possible Causes
Although the MCV value does not meet the criteria for macrocytosis, it is still important to consider possible causes of elevated MCV values. According to the studies 2, 3, common etiologies of macrocytosis include:
- Vitamin B12 and folate deficiencies
- Alcoholism
- Medications
- Hypothyroidism
- Liver disease
- Primary bone marrow dysplasias, including myelodysplasia and myeloproliferative disorders
Further Evaluation
To determine the underlying cause of the lab results, further evaluation, such as history and physical examination, vitamin B12 level, reticulocyte count, and a peripheral smear, may be necessary, as suggested by study 3. Additionally, if myelodysplastic syndrome (MDS) is suspected, along with leukocytopenia and/or thrombocytopenia with anemia, a hematology consultation may be appropriate, as recommended by study 2.