What does low RDW CV mean in a hematology test?

A low red cell distribution width (RDW-CV) in a hematology test can be indicative of:

- Conditions resulting in macrocytosis (enlarged red blood cells): These conditions include vitamin B12 or folate deficiency, liver disorders, hypothyroidism, celiac disease, leukemia, and myelodysplastic syndromes.

- Conditions resulting in uniform population of red blood cells (microcytosis or macrocytosis): For example, iron-deficiency anemia (microcytosis), sickle cell anemia (macrocytosis), genetic syndromes (hereditary spherocytosis, thalassemia).

- Hemoglobinopathies, where the structure or function of hemoglobin is abnormal, such as sickle cell anemia or thalassemia.

- Artificial causes such as storage conditions or blood collection techniques.

Therefore, a low RDW-CV may provide additional information in diagnosing hematological disorders or can help interpret the results of other red cell parameters, such as mean corpuscular volume (MCV). However, it's important to note that a low RDW-CV alone may not be enough to make a diagnosis, and your healthcare professional may recommend further testing or consider the broader clinical picture to determine the cause of the abnormality.