In this section
Reference ranges are provided for guidance in the interpretation of results for clinical decision making. They are conventionally set to give the range of values which would be found in approximately 95% of a statistically ‘Normal’ population.
Age-related reference ranges are provided as appropriate, but ranges do not take into account normal racial variation or differences between venous and capillary sample type. Please seek advice from the laboratory as necessary.
Unless otherwise stated the haematology reference ranges are selected from:
- published papers providing ranges established by national and/or international consensus,
- reference intervals provided by the instrument/assay manufacturer
Where applicable, reference ranges
- have been verified based on the local adult and paediatric population according to age/gender and detailed age-related reference ranges are available from the Department
- all ranges have been agreed by the department’s team of Consultant Haematologists
For further details on haematology reference ranges refer to:
- Dacie and Lewis Practical Haematology, 12th Edition: 2016, ISBN: 9780702066962 and
- Pediatric Hematology, 3rd Edition: 2006, ISBN: 9781405134002
Age-related reference ranges have been condensed to cover generally recognised stages of development and are generally added to the report automatically by the laboratory IT system when the result is generated. The following terms are used for age-related guidance:
- Newborn: First 7 days of life for term baby
- Neonate: First month of life for a term baby. Ranges may not apply to pre-term or small-for-dates babies
- Infant: Normally from the second month to one year, neonates are included in these ranges if not separately quoted
- Child: Normally one year to adolescence, neonates and infants are included in these ranges if not separately quoted
Full Blood Count reference ranges
Adult’s ranges were selected from Phase II of the Pathology Harmonisation Project published under pathologyharmony.co.uk and for children the ranges were selected from Pediatric Haematology.
- Pediatric Hematology, 3rd Edition: 2006
RJ Arceci (Ed), IM Hann (Ed) & OP Smith (Ed). ISBN: 9781405134002
Chapter 37, Reference values (PS Simpkin & RF Hinchliffe).
The selected ranges were verified based on the local adult and paediatric population according to age and gender.
Coagulation reference ranges
Adult’s ranges are taken from Sysmex published ranges and were then verified locally using normal donors and for children the ranges were selected from:
- Age dependency of coagulation parameters during childhood and puberty
IM Appel , B Grimminck et al. Journal of Thrombosis and Haemostasis 2012;10:2254–2263
- Age dependency for coagulation parameters in paediatric populations
Results of a multicentre study aimed at defining the age-specific reference ranges
P Toulon, M Berruyer et al. Thrombosis and Haemostasis 2016;116:9-16
- Ranges published by Sysmex Corporation (Sysmex UK Ltd) and provided by Great Ormond Street NHS Foundation Trust
Abnormal Haemoglobin and related reference ranges
Haemoglobin A2 and F reference ranges were verified on the local adult and paediatric population with reference to the leading article:
- Significant haemoglobinopathies: guidelines for screening and diagnosis
K Ryan, BJ Bain et al. British Journal of Haematology 2010;149:35–49
Glucose 6 Phosphate Dehydrogenase (G6PD) assay reference ranges were selected from those used by Sheffield Teaching Hospitals NHS Foundation Trust and verified on the local adult population.
Erythropoietin assays reference ranges were selected from Leeds Teaching Hospital NHS foundation Trust, using the manufacturer Beckman Coulter published ranges as a guide and were verified on the local adult population.
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Erythrocyte Sedimentation Rate (ESR)
Female/Males less than 16 years old – 4-10 mm per first hour
Females (greater than 16 years old) – 0–7 mm per first hour
Males (greater than 16 years old) – 0–5 mm per first hour
Plasma Viscosity
(mPa/s at 25°C)
Two Key advantages when compared to the ESR test:
- Plasma Viscosity Results are calibrated to a primary standard
- Plasma Viscosity is not altered by co-existing non-related factors e.g. anaemia
| <1.50 mPa/s |
Children <3 years Hypoproteinaemia (can be due to chemotherapy) |
| 1.50 – 1.72 mPa/s | Normal Adult range |
| 1.72 – 1.80 mPa/s | Equivocal result suggest repeat after appropriate time |
| 1.80 – 2.00 mPa/s | Suggestive of chronic condition |
| 2.00 – 2.30 mPa/s | Suggestive of acute condition |
| >2.30 | Suggestive of Myeloma |
| >2.90 | Hyperviscosity. Exclude Macroglobulinaemia as the cause |
Glandular Fever Screen
Limitations for infectious mononucleosis (glandular fever): the test detects heterophile antibodies in whole blood. Approximately 10% of adults and up to 40% of children under the age of 5 years do not produce these antibodies so will give a negative screening test. Always consider the test result in combination with clinical symptoms and results of the white cell differential.
TopCoagulation
For significantly abnormal results suggest discussion with Haematology Consultant or Senior Registrar.
Adult – Haemostasis SPR bleep number 2022.
Paediatrics – ask switch to page Dr Grainger.
If we are unable to reach any ward/department with significantly abnormal results which require immediate action we will bleep the Lead Nurse on 2677.
TopISTH DIC scoring system
The ISTH group produced a simple scoring system for the diagnosis of DIC depending on the Platelet count, the PT, the fibrinogen level and critically the FDP/D-Dimer results:
| Parameter | Result | Score |
| 1. Platelet count |
>100×109/l <100×109/l < 50×109/l |
0 1 2 |
| 2. PT |
<3s prolonged >3s but <6s >6s |
0 1 2 |
| 3. Fibrinogen |
>1.0g/l <1.0g/l |
0 1 |
| 4. FDP/D-Dimer |
No increase Moderate increase Strong increase |
0 2 (250-5,000) 3 (>5,000) |
A total score of ≥5 = DIC as long as the score is associated with a clinical disorder known to cause DIC. If the score is ≥5 you must ring the ward/medic and make them aware of the risk of DIC.
Guidance note: D-dimer testing in the diagnosis of venous thromboembolism (VTE) in hospital patients
- VTE is highly unlikely in patients who are judged by means of a clinical scoring system to be clinically unlikely to have VTE, and who have a negative D-dimer test.
- D-dimer testing has very limited usefulness to aid diagnosis in patients where the clinical probability of VTE is high.
- D-dimer is frequently raised in hospital inpatients without VTE.
- D-dimer is increased in infection, cancer, inflammation, surgery, trauma, ischaemic heart disease, stroke, pregnancy, sickle cell disease & trait.
- D-dimer testing is not useful in the diagnosis of VTE in patients with concomitant diseases.
- There is a decrease in the specificity of D-dimer testing for VTE with increasing age (i.e. D-dimer testing is less reliable in older patients).
- D-dimer should not be used to exclude VTE in children. The negative predictive value of D-dimer in children with suspected VTE has not been validated and levels may vary with age.
Guidance
- D-dimer testing should only be requested in patients with a low clinical probability of VTE, or in the assessment of recurrence risk for VTE post completion of anticoagulant therapy.
- In patients with a high clinical probability of VTE, or in patients with co-existing illness, D-dimer testing is unlikely to add any useful diagnostic value and should not be requested.
Reference
Thacil J et al, Appropriate use of D-dimer in hospital patients. Am J Med 2010, 123, 17-9.
- Guidance on Laboratory testing for Heritable Thrombophilia is available to view on the Trust intranet
- Detailed information and guidance on “Thromboprophylaxis in Pregnancy and the Puerperium” is available on the Intranet in the maternity section of Policies
Guidance on Laboratory testing for Heritable Thrombophilia
Detailed information and guidance on “VTE Prophylaxis in Pregnancy and the Puerperium” is available
on the Intranet in the maternity section of Policies.
Warfarin scheme
| Day | APTT (9-10am) target | Heparin dose | IF INR | Warfarin dose given at 5pm |
| 1 Start | 2-3 ratio | As per APTT | < 1.4 | 10 mg |
| 2 | – | As per APTT |
< 1.8 |
10 mg |
| 1.8 | 1 mg | |||
| > 1.8 | 0.5 mg | |||
| 3 | 2-3 ratio | As per APTT | <2.0 | 10 mg |
| 2.0-2.3 | 5 mg | |||
| 2.4-2.7 | 4 mg | |||
| 2.8-3.1 | 3 mg | |||
| 3.2-3.4 | 2 mg | |||
| 3.5-4.0 | 1 mg | |||
| >4.0 | NIL | |||
| 4 | – | Stop heparin | Predicted maintenance | |
| >8 mg | ||||
| <1.4 | 8 mg | |||
| 1.4 | 7.5 mg | |||
| 1.5 | 7 mg | |||
| 1.6-1.7 | 6.5 mg | |||
| 1.8 | 6 mg | |||
| 1.9 | 5.5 mg | |||
| 2.0-2.1 | 5 mg | |||
| 2.2-2.3 | 4.5 mg | |||
| 2.4-2.6 | 4 mg | |||
| 2.7-3.0 | 3.5 mg | |||
| 3.1-3.5 | 3 | |||
| 3.6-4.0 | ||||
| Nil then 2 mg | ||||
| 4.1-4.5 | ||||
| >4.5 | Nil for two days and then 1mg |
Guidelines for Heparin Dosage for Heparinization for Thrombotic Conditions
Take baseline PT APTT Give 5,000 i.v. bolus then start pump at 30,000 units over 24 hrs (eg 30,000 units in 24 mls of N Saline and set pump at 1ml per hour) Repeat APTT after 6 hrs
| Bolus | Rate | Repeat APTT | |
| APTT Ratio <1.5 | 5,000 | +2,500 units over 24 hrs | 6hr-12hr |
| APTT Ratio 1.5-2.0 | Nil | +2,500 units over 24 hrs | 6hr-12hr |
| APTT ratio 2.0-3.0 | Nil | Same dose | Next Morning |
| APTT Ratio 3.0-3.5 | Nil | -2,500 units over 24 hrs | Next Morning |
| APTT Ratio 3.5-4.0 | Nil | Stop for 1 hr then -2,500 units over 24 hrs | 6hr-12hr |
| APTT Ratio >4.0 | Nil | Stop for 2hr then -5,000 units over 24 hrs | 6hr-12hr |
For S.C.Heparin 250 iu/kg b.d. [200 for females > 60yrs]
Take specimen 4-6hrs post injection
| APTT RATIO | DOSE ADJUSTMENT | REPEAT APTT |
| <1.5 | +2,500 units b.d | Next Morning |
| 1.5-2.0 | +1.250 units b.d. | Next Morning |
| 2.0-3.0 | No change | Next Morning |
| 3.0-3.5 | -1,250 units b.d. | Next Morning |
| 3.0-4.0 | -2,500 units b.d | Next Morning |
| >4.0 | -5,000 units b.d | Next Morning |
Haematinics
| Erythropoeitin (EPO) | 3-18 mIU/mL |
Red cell investigations
| Haemoglobin A2 | 2.3 – 3.3% |
| Haemoglobin F | < 1.5% |
| G6PD |
11.2 – 18.8 μg/l 0-6 months 7.3 – 14.1 μg/l >6 months old |
G6PD Assay and the testing of travel controls from external sites
When referring tests to MFT we require a completely anonymised sample, that is suspected to be normal but taken under similar circumstances and of similar age to accompany the test samples as a “travel control”. The travel control will only be tested in the event of abnormal results on the patient test samples to ascertain that abnormal results are not due to unknown issues which may affect samples during transit. Should the travel control then also show abnormal results the patient test results will be rejected, and a repeat sample requested as it may be assumed that the test results are not reliable due to poor travel conditions. No results will ever be reported on the anonymised travel control. It is a UKAS requirement that the influence of travel conditions is considered when interpreting results.
This list is not exhaustive – there may be other factors affecting the reporting of results which are not listed
Top(Last reviewed June 2025)