From the Guidelines
A reticulocyte count of 1.2 is indicative of a low reticulocyte index (RI), suggesting decreased RBC production. This is based on the fact that a normal RI ranges between 1.0 and 2.0, and a value of 1.2 is below the upper limit of this range, but still may indicate a problem with red blood cell production, especially if the patient has anemia 1.
Possible Causes
Some possible causes of a low RI include:
- Iron deficiency
- Vitamin B12 or folate deficiency
- Aplastic anemia
- Bone marrow dysfunction caused by cancer or cancer-related therapy (radiation or myelosuppressive chemotherapy) 1
Evaluation Approach
The evaluation of anemia can be approached in two ways: morphologic and kinetic. The morphologic approach characterizes anemia based on the mean corpuscular volume (MCV), while the kinetic approach focuses on the underlying mechanism of anemia, distinguishing among the production, destruction, and loss of RBCs 1.
Next Steps
To further evaluate the cause of the low RI, additional tests such as iron and total iron binding capacity (TIBC), vitamin B12 or folate levels, stool guaiac, endoscopy findings, Coombs test, and disseminated intravascular coagulation panel may be necessary 1. Treatment should be aimed at addressing the underlying cause of the anemia, and may involve iron supplementation, vitamin B12 or folate replacement, or other therapies as indicated.
From the Research
Reticulocyte Count
- A reticulocyte count of 1.2 is within the range of values that can be obtained using different methods for reticulocyte analysis 2, 3.
- The accuracy and precision of manual reticulocyte counts can be increased by using a Miller disc reticle, as compared to other ruled reticles or no reticle 2.
- Automated methods for reticulocyte analysis, such as the ABX Pentra 120 Retic haematological analyser, Coulter EPICS XL MCL flow cytometer, and Coulter STKS haematology system, can provide efficient and reliable determination of reticulocyte counts 3.
- However, differences in reticulocyte counts can exist between methods, and these should be taken into account when determining normal values 3.
Comparison of Methods
- The Miller disc method has been shown to be the most precise and accurate manual method for reticulocyte counting, as compared to other manual methods 2.
- Automated methods have been compared, and the results show that the reticulocyte concentrations can vary slightly between methods, but the correlations between methods are significant 3.
- The within-batch and between-batch coefficients of variation for the different methods can also vary, indicating differences in precision and accuracy 3.