Blood Sciences

Routine Haematology Testing

Full Blood Counts and Reticulocyte Counts are performed using Sysmex XE2100 technology. We achieve a turnaround time of 1 hour for acute testing and 6 hours for routine results. The department examines almost 2000 samples for Full Blood Count every day.

Haemoglobin and Red Cell Indices: Haemoglobin is a molecule found within red blood cells and carries oxygen around the body. The term “red cell indices” refers to the size of, and haemoglobin content of red cells (MCH, MCV and MCHC). These parameters form part of a Full Blood Counts and are used by clinicians and biomedical scientists to assess anaemia and its possible causes, highlighting possible iron, vitamin B12 or folate deficiency. Red cell indices are also useful in the diagnosis of a range of diseases or conditions including sickle cell disease, thalassaemia, haemolysis, liver disease and kidney disease.

White cells in the blood fight infection and are also increased during injury or stress. The white cell count is part of the Full Blood Count. It can be used as an indicator of immune response to possible infection or inflammation, or may be indicative of malignancy. They are often monitored alongside the platelet count in patients undergoing chemotherapy or other cytotoxic treatments. The white cell count can be split into 5 different types of white cell: Neutrophil, Lymphocyte, Monocyte, Eosinophil and Basophil. Increases in a particular type of white cell count can point a clinician or scientist to the cause of an illness, for instance suggesting possible viral, bacterial or parasitic infection.

Blood film morphology is examined on approximately 7% of all Full Blood Counts performed and has a turnaround time of approximately 3 working days. Blood is spread thinly onto a glass slide and treated with specialist stains so that blood cells can be examined with a microscope. Inspection of the shape, colour and size of blood cells by specialist scientists can help in the diagnosis of various diseases and conditions, such as anaemia, sickle cell disease, thalassaemia, glandular fever, infection, malaria and other parasites, haematological malignancy and metabolic deficiencies.

Routine Coagulation Screening

This includes the Prothrombin Time (PT) and the Activated Partial Thromboplastin Time (APTT) and may also include a Fibrinogen level. The result turnaround times are 1 hour for acute work and 4 hours for routine samples. The analyser used for coagulation testing in our department is the IL-TOP. We perform 300-400 coagulation screening tests per day.

Coagulation screening is performed to assess the time taken for a patient’s blood to clot. Normal haemostasis is a balance of the blood forming clots in response to injury (often very small and unnoticeable) and later dissolving these clots when tissue has healed. Defects in this process can occur making the body’s response and clotting ability inadequate (e.g. haemophilia) or too prone to clot formation (e.g. deep vein thrombosis).

INR testing or a selection of the tests mentioned previously is used to assess the body’s response to anticoagulant drugs. The results help clinicians to use the correct dose and type of anticoagulants.

Specialist coagulation tests are also performed in the haematology laboratory. These are used to measure the amount and function of coagulation factors in the blood and to diagnose inherited blood clotting disorders such as haemophillia. Turnaround times for these more specialist tests are 2 hours for acute samples (authorised by consultant haematologists) or 7 days for routine investigations.

Other Specialist Tests

Less common and more specialised tests which we perform include:

Screening for sickle cell disease or thalassaemia

As well as routine diagnosis for many patients, this is performed on all pregnant women to assess the risk of the baby inheriting an abnormal haemoglobin. Techniques used are ion exchange HPLC and electrophoresis.

Platelet aggregation studies

Platelets are blood cells which form a vital part of a blood clot. This test gives an assessment of the ability of platelets to adhere to each other during blood clot formation, and may help a doctor to find the cause of excessive bruising or bleeding in a patient. The test uses specialist equipment and reagents to measure light transmission through the blood sample and assess the amount of platelet aggregation.

Quality Assurance

As a department we strive for continuous improvement and a high quality service. The department participates in National External Quality Assurance Schemes (NEQAS) where available. These schemes allow us to compare our results to those from other laboratories across the UK and continually assess our performance.

Internal Quality Assessment is performed via approved IQC and calibrators for our instruments, a robust and meaningful audit schedule for our procedures, and a culture of safety and honesty, where incident reporting is encouraged and corrective and preventative actions taken.

We aim to make our test repertoire appropriate to our service and our results meaningful to the clinician.