Order Code LABRETB Reticulocyte Profile, Blood
Additional Codes
Mayo Test Code : RETB
Specimen Required
Container/Tube: Lavender top (EDTA)
Specimen Volume: 3 mL
Collection Instructions: Send whole blood specimen in original tube. Do not aliquot.
Useful For
Assessing erythropoietic bone marrow activity in anemia and other hematologic conditions
Assessment of acute iron deficiency
Monitoring early response to iron therapy or erythropoiesis-stimulating agents
Early monitoring of therapy for nutritional anemias (eg, megaloblastic, iron deficiency) where immature reticulocyte fraction precedes reticulocyte count increase by several days
Monitoring therapeutic efficacy of erythropoietin treatment
Monitoring early engraftment after bone marrow transplantation
Method Name
Flow Cytometry
Reporting Name
Reticulocyte Profile, BSpecimen Type
Whole Blood EDTASpecimen Minimum Volume
0.5 mL
Specimen Stability Information
Specimen Type | Temperature | Time |
---|---|---|
Whole Blood EDTA | Refrigerated (preferred) | 48 hours |
Ambient | 24 hours |
Reject Due To
Gross hemolysis | Reject |
Gross lipemia | OK |
Gross icterus | OK |
Clotted | Reject |
Reference Values
% RETICULOCYTES
1-3 days: 3.47-5.40%
4 days-4 weeks: 1.06-2.37%
5 weeks-7 weeks: 2.12-3.47%
8 weeks-5 months: 1.55-2.70%
6 months-23 months: 0.99-1.82%
24 months-5 years: 0.82-1.45%
6-11 years: 0.98-1.94%
12-17 years: 0.90-1.49%
Adults: 0.60-2.71%
ABSOLUTE RETICULOCYTES
1-3 days: 147.5-216.4 x 10(9)/L
4 days-4 weeks: 51.3-110.4 x 10(9)/L
5 weeks-7 weeks: 51.8-77.9 x 10(9)/L
8 weeks-5 months: 48.2-88.2 x 10(9)/L
6 months-23 months: 43.5-111.1 x 10(9)/L
24 months-5 years: 36.4-68.0 x 10(9)/L
6-11 years: 42.4-70.2 x 10(9)/L
12-17 years: 41.6-65.1 x 10(9)/L
Adults: 30.4-110.9 x 10(9)/L
IMMATURE RETICULOCYTE FRACTION (IRF)
1-3 days: 30.5-35.1%
4 days-4 weeks: 14.5-24.6%
5 weeks-2 months: 19.1-28.9%
3-5 months: 13.4-23.3%
6 months-<2 years: 11.4-25.8%
2-<6 years: 8.4-21.7%
6-<12 years: 8.9-24.1%
12-<18 years: 9.0-18.7%
≥ 18 years:
Female:3.0-15.9%
Male: 2.3-13.4%
RETICULOCYTE HEMOGLOBIN
Males:
1 day-5 months: 27.6-38.7 pg
6 months-<2 years: 28.7-35.7 pg
2-<6 years: 27.7-37.8 pg
6-<12 years: 32.4-37.6 pg
12-<18 years: 30.0-37.6 pg
Adults: 30.0-37.6 pg
Females:
1 day-5 months: 29.2-37.5 pg
6 months-<2 years: 30.1-35.7 pg
2-<6 years: 29.3-37.3 pg
6-<12 years: 30.4-39.7 pg
12-<18 years: 30.0-37.6 pg
Adults: 30.0-37.6 pg
RED BLOOD CELL COUNT (RBC)
Males:
0-14 days: 4.10-5.55 x 10(12)/L
15 days-4 weeks: 3.16-4.63 x 10(12)/L
5 weeks-7 weeks: 3.02-4.22 x 10(12)/L
8 weeks-5 months: 3.43-4.80 x 10(12)/L
6 months-23 months: 4.03-5.07 x 10(12)/L
24 months-35 months: 3.89-4.97 x 10(12)/L
3-5 years: 4.00-5.10 x 10(12)/L
6-10 years: 4.10-5.20 x 10(12)/L
11-14 years: 4.20-5.30 x 10(12)/L
15-17 years: 4.30-5.70 x 10(12)/L
Adults: 4.35-5.65 x 10(12)/L
Females:
0-14 days: 4.12-5.74 x 10(12)/L
15 days-4 weeks: 3.32-4.80 x 10(12)/L
5 weeks-7 weeks: 2.93-3.87 x 10(12)/L
8 weeks-5 months: 3.45-4.75 x 10(12)/L
6 months-23 months: 3.97-5.01 x 10(12)/L
24 months-35 months: 3.84-4.92 x 10(12)/L
3-5 years: 4.00-5.10 x 10(12)/L
6-10 years: 4.10-5.20 x 10(12)/L
11-14 years: 4.10-5.10 x 10(12)/L
15-17 years: 3.80-5.00 x 10(12)/L
Adults: 3.92-5.13 x 10(12)/L
Method Description
The Sysmex XN reticulocyte analysis is based on flow cytometry method using a semiconductor laser. A two-dimensional scattergram is plotted, with the X-axis representing the intensity of the side fluorescent light, and the Y-axis representing the intensity of the forward scattered light. This scattergram displays groups of reticulocytes, mature red blood cells, and platelets.
The scattergram is divided into three reticulocyte (RET) zones based on the intensity of the fluorescent light, and the ratio of the reticulocytes in each zone to the total number of reticulocytes is calculated.
The immature reticulocyte fraction (IRF) is obtained as a ratio of reticulocytes count in the area with strong fluorescent light intensity in the RET scattergram (IRF zone), to the total reticulocytes count.
RET-He (reticulocyte hemoglobin equivalent) is a unique parameter developed by Sysmex that is derived using the reticulocyte scattered light signals and a proprietary Sysmex calculation equation.(Instruction manual: Automated Hematology Analyzer XN series [XN-9000/XN-9100] North American Edition, Code No. BF691913 en-am. Sysmex Corp; rev: 09/2022)
Day(s) Performed
Monday through Sunday
Performing Laboratory

CPT Code Information
85046
Forms
If not ordering electronically, complete, print, and send a Benign Hematology Test Request (T755) with the specimen.