From the Guidelines
Iron deficiency anemia is the most likely cause of anemia with elevated Red Blood Cell (RBC) count, high Red Cell Distribution Width (RDW), and low Mean Corpuscular Volume (MCV), as it leads to increased RBC production, smaller red blood cells, and variable cell sizes. In this condition, the body produces more red blood cells to compensate for their reduced oxygen-carrying capacity, resulting in elevated RBC counts 1. The MCV (mean corpuscular volume) is low because iron deficiency leads to smaller red blood cells (microcytosis) 1. The RDW (red cell distribution width) is high because there's significant variation in red cell size as the body produces both normal and small cells during the development of iron deficiency.
Some key points to consider in the diagnosis of iron deficiency anemia include:
- Serum ferritin level < 30 μg/L in the absence of inflammation, or < 100 μg/L in the presence of inflammation, indicates iron deficiency 1
- Transferrin saturation level < 16% is a sensitive marker of iron deficiency, although it has low specificity 1
- Elevated CRP or ESR levels can indicate inflammation, which can affect iron metabolism and serum ferritin levels 1
- Reticulocyte count can help distinguish between iron deficiency anemia and anemia of chronic disease (ACD) 1
Other conditions, such as thalassemia minor, can also present with similar laboratory findings, but require different treatments. Distinguishing between these conditions often requires additional tests like serum ferritin, iron studies, or hemoglobin electrophoresis 1.
In terms of treatment, iron supplementation (typically ferrous sulfate 325mg daily for 3-6 months) is the standard treatment for iron deficiency anemia, while thalassemia is genetic and may not require specific treatment in its minor form. It is essential to determine the underlying cause of anemia to provide effective treatment and improve patient outcomes.
From the Research
Anemia with Elevated RBC Count, High RDW, and Low MCV
- Anemia with an elevated Red Blood Cell (RBC) count, high Red Cell Distribution Width (RDW), and low Mean Corpuscular Volume (MCV) can be caused by several factors, including:
- A high RBC count combined with a low MCV is generally attributed to thalassemia minor or polycythemia vera with iron deficiency 5
- Iron deficiency anemia can be predicted by a high RDW and low MCV, even before anemia develops or during recovery 2, 3, 4
- A high RDW is a sensitive and specific indicator of iron deficiency anemia, especially in the latent stage 4
- The combination of a high RBC count and high RDW may indicate polycythemia vera, especially if the MCV is low 6
- The RBC count and RDW can be used as diagnostic markers for polycythemia vera, in combination with other tests such as the erythrocyte sedimentation rate (ESR) 6