Table 8.1-1. Classification of anemias based on the reticulocyte count, mean corpuscular volume, and red cell distribution width

MCV

RDW

RC ≥100,000/microL

RC <100,000/microL

Microcytic MCV ↓

N

Beta thalassemia

Anemia of chronic disease (some cases)

Beta thalassemia

– Iron deficiency anemia

– Inherited sideroblastic anemia (some cases)

Normocytic MCV (N)

N

– Very early phases of major bleeding

– Anemia of chronic disease (most cases)

– Anemia in chronic kidney disease

– Aplastic anemia

– Anemia due to acute blood loss

– Most of hemolytic anemias

– Early stage of iron deficiency anemia

– Cobalamin or folate deficiency

– Mixed-type anemia (eg, combined iron and cobalamin deficiency)

– Myelodysplastic syndrome

Macrocytic MCV ↑

N

Chronic liver disease

– Chemotherapy

– Alcohol dependency

– Aplastic anemia

– Some autoimmune hemolytic anemias (due to reticulocytosis)

– Chronic liver disease

– Cobalamin or folate deficiency

– Myelodysplastic syndrome

↑, increased; ↓, decreased; MCV, mean corpuscular volume; N, normal; RC, reticulocyte count; RDW, red cell distribution width.