Reticulocyte count
Other names: Reticulocyte Index; Retic Count; Corrected Reticulocyte
Reticulocytes are immature red blood cells, which are produced in the bone marrow. Most of the red blood cells released into the bloodstream are mature cells; however, around 0.5-2% of the red blood cells in the bloodstream will be reticulocytes. The test is used to measure the number of reticulocytes in the blood; it can be used as a marker for bone marrow function.
Red blood cells usually survive for around 120 days and the body constantly replenishes the stock of red blood cells; this is done in the bone marrow. If the production of new cells is disturbed, this may lead to a decrease in the number of red blood cells in the bloodstream and this contributes to anaemia.
When is the test used?
The test is done to assess the function of the bone marrow and to check that enough red blood cells are being produced. The test is also used to distinguish between different types of anaemia; other blood tests are usually ordered if the doctor suspects that a patient has anaemia. The test is usually carried out as part of a series of tests which make up the full blood count.
The reticulocyte test is usually ordered when the results of other blood tests show that the patient has a low red blood cell count; it is also ordered when the patient has symptoms of anaemia, including pale skin, tiredness, lethargy, weakness, breathing difficulties and blood in the stools.
The test may also be ordered when a patient has iron or vitamin B12 or folate deficiencies.
How is the test done?
The test is done by taking a sample of blood from the patient’s arm; a needle is inserted into a vein (usually on the inside of the elbow) and the blood is drawn out into a syringe. Once the sample has been collected, the blood will be placed in a sample bottle, labelled with the patients name and sent for testing at the laboratory.
If the patient is a very small child or baby, the sample will be collected from their heel; a needle will be used to prick the heel and the blood will be collected and analysed.
What do the test results show?
The test results should give the doctor an idea of how effectively the patient’s bone marrow is working; in order to evaluate the results, a calculation is done to measure the corrected reticulocyte count or the reticulocyte index.
An increased reticulocyte percentage may indicate that patient has iron deficiency anaemia, haemolytic anaemia, aplastic anaemia or pernicious anaemia; raised levels may also be associated with haemorrhages and radiation therapy.
Specific Blood Tests
- Specific Blood Tests
- Factor V Leiden Mutation and PT 20210 Mutation
- Ferritin Test
- Fibrinogen
- Fructosamine
- FSH Test
- G6PD
- Gastrin
- GGT
- Glucose test
- Growth hormone
- Haemoglobin
- Haptoglobin
- HbA1c test
- HDL Cholesterol Test
- Helicobacter Pylori test
- Heparin Anti-Xa
- Hepatitis A Virus
- Hepatitis B Virus
- Hepatitis C Virus
- Her-2/neu Testing
- Heterophil Antibody Titre
- High-Sensitivity C-Reactive Protein
- HIV Antibody Test
- HIV Resistance Testing
- HIV Viral Load
- IGF-1
- Immunoreactive Trypsin
- Insulin
- Iron test
- LDH
- LDL Cholesterol Test
- Lead Test
- LH Test
- Lipase Test
- Lipoprotein (a)
- Lithium
- Lupus Anticoagulant
- Lyme disease test
- Maternal screening
- Mercury, Urine and Blood
- Mycophenolic Acid
- Myoglobin Test
- Oestrogen
- Osmolality
- Overdose Drug Test
- Paracetamol
- Parathyroid Hormone
- Parvovirus B19
- PCV
- Pertussis
- Phenobarbital
- Phenytoin
- Phospate
- Platelet Count
- Porphyrins
- Potassium Test
- Prealbumin Test
- Procalcitonin
- Progesterone Test
- Prolactin
- Prostate-Specific Antigen
- Protein 24 Capsid Antigen
- Protein C and Protein S
- Protein Electrophoresis Immunofixation Electrophoresis
- Prothrombin Time
- PSEN1 Test
- PTH
- Reticulocyte count
- Rheumatoid factor
- Rubella test
- Salicylic Acid
- Serotonin
- Sex Hormone Binding Globulin
- Sickle Cell Test
- Sirolimus
- Smooth Muscle Antibody
- Sodium Test
- Soluble Mesothelin-Related Peptides
- Synacthen Test
- Syphilis Test
- Tacrolimus
- Tau protein
- Testosterone Test
- Theophylline & Caffeine
- Thiopurine s-methyltransferase
- Thyroglobulin (Tg)
- Thyroid peroxidase antibody (TPOAb)
- Thyroid-Stimulating Hormone
- Thyroxine
- TIBC, UIBC & Transferring
- TORCH Test
- Total Protein test
- Triiodothyronine
- Triglycerides Test
- Troponin test
- Urea test
- Uric Acid
- Valproic Acid
- Vancomycin
- Very Low Density Lipoprotein
- Vitamin B12 and Folate
- Vitamin D
- West Nile Virus
- White blood cell differential count
- Zinc Protoporphyrin
- Activated Clotting Time
- ACTH
- Albumin
- Aldosterone and Renin
- Alkaline Phosphatase Test
- Allergen-Specific IgE Antibody Test
- Alpha-1 Antitrypsin
- Alpha-Fetoprotein
- ALT
- AMA
- Ammonia
- Amylase Test
- Angiotensin Converting Enzyme
- Antinuclear Antibody
- Antithrombin
- Apolipoprotein A-I
- Apolipoprotein E Genotyping
- aPTT
- AST
- Bicarbonate
- Bilirubin
- Blood cultures
- Blood film
- Blood Gas Tests
- Blood Ketones
- Brain Natriuretic Peptide
- BRCA-1 & BRCA-2
- CA 125
- Cancer Antigen 15-3
- Cancer Antigen 19-9
- C-peptide
- Caeruloplasmin
- Calcitonin
- Calcium Test
- Carbamazepine
- Cardiac Risk Assessment
- Cardiolipin Antobodies
- Catecholamines, Plasma and Urine
- CCP
- CD4 and CD8
- CEA Test
- CF Gene Mutation Testing
- Chickenpox and Shingles Tests
- Chloride Test
- Cholesterol Test
- Chlorinesterase Test
- Chromogranin A
- Ciclosporin
- CMV
- Coagulation Factors
- Coeliac Disease Tests
- Copper
- Cortisol Test
- Creatine Kinase CK-MB Test
- Creatine Kinase Test
- Creatinine
- Creatinine Clearance
- C-Reactive Protein
- Cystatin C
- D-Dimer
- DHEAS
- Digoxin
- Direct LDL cholesterol
- eGFR - Calc. Creatinine Clearance
- Electrolytes
- Epstein-Barr Virus Antibodies
- Erythrocyte Sedimentation Rate
- Erythropoietin
- Ethanol
Blood Test Guide
- Blood Tests
- Types of blood tests
- what to expect
- What are the risks of blood tests?
- What do blood tests show?
- Specific Blood Tests