Reticulocyte - Interpretation

Interpretation

The normal range of values for reticulocytes in the blood depends on the clinical situation and the lab, but, in general terms, is 0.5% to 1.5%. However, if a person has anemia, his/her reticulocyte percentage should be higher than "normal" if the bone marrow's ability to produce new blood cells remains intact. Thus, calculating the reticulocyte production index is an important step in understanding whether the reticulocyte count is appropriate or inappropriate to the situation. This is often a more important question than whether the percentage is in the normal range; for instance, if someone is anaemic but has a reticulocyte percentage of only 1%, the bone marrow is likely not producing new blood cells at a rate that will correct the anaemia. The number of reticulocytes is a good indicator of bone marrow activity, because it represents recent production. This means that the reticulocyte count, and the reticulocyte production index that can be calculated from it, can be used to determine whether a production problem is contributing to the anaemia, and can also be used to monitor the progress of treatment for anaemia.

When there is an increased production of red blood cells to overcome chronic or severe loss of mature red blood cells, such as in a haemolytic anaemia, people often have a markedly high number and percentage of reticulocytes. A very high number of reticulocytes in the blood can be described as reticulocytosis.

Abnormally low numbers of reticulocytes can be attributed to chemotherapy, aplastic anaemia, pernicious anaemia, bone marrow malignancies, problems of erythropoietin production, various vitamin or mineral deficiencies (B₉, B₁₂, iron), disease states (anaemia of chronic disease) and other causes of anaemia due to poor RBC production.