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HelpMayo Test ID RTIC Reticulocytes, Blood
Necessary Information
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
Method Name
Flow Cytometry
Reporting Name
Reticulocytes, BSpecimen Type
Whole Blood EDTASpecimen Minimum Volume
0.5 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Whole Blood EDTA | Refrigerated (preferred) | 48 hours | |
| Ambient | 24 hours |
Reject Due To
| Gross hemolysis | Reject |
| Gross lipemia | OK |
| Gross icterus | OK |
| Clotted | Reject |
Clinical Information
Reticulocytes are immature erythrocytes (red blood cells) that have been released into the peripheral blood from the bone marrow after extrusion of their nucleus. The reticulocyte contains residual polyribosomes used in the formation of hemoglobin in the developing erythrocyte.
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
Interpretation
The reticulocyte count is a measure of the number of red blood cells delivered by the bone marrow. It is elevated with active erythropoiesis, such as regeneration and is decreased in hypoplastic or deficiency conditions, such as vitamin B12 deficiency.
Cautions
Reticulocyte counts must be carefully correlated with other clinical and laboratory findings.
Clotted specimens yield unreliable results and are unacceptable for analysis.
Clinical Reference
1. Adeli K, Raizman J, Chen Y, et al. Complex biological profile of hematologic markers across pediatric, adult, and geriatric ages: establishment of robust pediatric and adult reference intervals on the basis of the Canadian Health Measures Survey. Clin Chem. 2015;61(8):1075-1086
2. Clinical and Laboratory Standards Institute (CLSI). Defining, Establishing, and Verifying Reference Intervals in the Clinical Laboratory; Approved Guideline. 3rd ed. CLSI document EP28-A3c. CLSI; 2008
3. Soldin J, Brugnara C, Wong EC. Pediatric Reference Intervals. 5th ed. AACC Press; 2005
4. Lotspeich-Steininger CA, Stiene-Martin EA, Koepke JA. Clinical Hematology: Principles, Procedures, Correlations. 2nd ed. Lippincott-Raven; 1998: 114-117
Method Description
The Sysmex XN 9100 reticulocyte analyzer is a flow cytometer that uses an argon laser as the light source. Whole blood specimens are stained with polymethine fluorescent dye and passed through the laser beam in a sheath flow cell. Each blood cell causes a forward light scatter that depends on cell size. This measurement permits a separation of the various blood cell types so that only erythrocytes are included in the cell count. Erythrocytes containing the protein reticulin (ie, reticulocytes) are stained by the dye in the laser beam. The right-angle fluorescence is measured to count these stained cells. The instrument counts 30,000 erythrocytes in each specimen. Because a known aliquot is counted, an actual red blood cell per unit volume is performed and an absolute reticulocyte count is obtained.(Instruction manual: Automated Hematology Analyzer XN series [XN-9000/XN-9100] North American Edition. Code No. BF691913 en-am. Sysmex Corp; 09/2022)
Day(s) Performed
Monday through Sunday
Report Available
1 daySpecimen Retention Time
3 daysPerforming Laboratory
Mayo Clinic Laboratories in Rochester
Test Classification
This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.CPT Code Information
85045
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| RTIC | Reticulocytes, B | 50262-5 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| PRTIC | Reticulocytes, B | 17849-1 |
| ARTIC | Absolute Reticulocyte | 60474-4 |