Not medically reviewed
Haematology
Reticulocyte count
Not medically reviewed · Content last updated · 1 min read ·
This is the date the draft was written, not a medical review date.
Reticulocytes are immature red cells released from the marrow and indicate effective erythropoiesis. The absolute count (about 25-75 x10^9/L) or reticulocyte index is more informative than the percentage in anaemia.
Reference interval
| Conventional (% of red cells) | SI (fraction of red cells) | |
|---|---|---|
| Adults | 0.5–2.5 % of red cells | 0.005–0.025 fraction of red cells |
Specimen: Whole blood (EDTA) · Conventional × 0.01 = SI
Causes of high values
Haemolytic anaemia, acute blood loss, response to treatment of iron, B12 or folate deficiency, and recovery after marrow suppression.
Causes of low values
Hypoproliferative anaemia: aplastic anaemia, pure red cell aplasia, marrow infiltration, untreated iron, B12 or folate deficiency, chronic kidney disease and chemotherapy.
Pre-analytical and method notes
Methods (supravital stain versus automated flow cytometry) and reference intervals differ between laboratories, and neonates have higher values. Correct the percentage for the degree of anaemia (corrected count or reticulocyte index) before interpretation.
References
- Rifai N, Horvath AR, Wittwer CT. Tietz Textbook of Clinical Chemistry and Molecular Diagnostics. Elsevier, 6th edition (2018) — Tier 3 (textbook)
- Loscalzo J, et al.. Harrison's Principles of Internal Medicine. McGraw-Hill, 21st edition (2022) — Tier 3 (textbook)
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