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Haematology Services

The Haematology department provides routine and emergency diagnostic services for patient diagnosis and management. These services are based around the main analysers in the laboratory, mainly the Full Blood Count analysers, the coagulation analysers and blood film morphology. A number of specialised tests are routinely referred to reference laboratories. The more popular referral tests are included at the end of this section and a full list of referral tests can be seen in the main Blood Sciences page.

 

 

Routine Tests

Full Blood Count

PURPLE capped Vacutainer tube, EDTA anticoagulant (4 ml)

The FBC is processed by an automated cell counter.  Haemoglobin (Hb), red cell count (RBC), packed cell volume (Hct), mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), mean corpuscular haemoglobin concentration (MCHC), white blood cell count (WBC), platelet count and an analyser differential will be provided automatically. A blood film will be reviewed and a manual differential white blood cell count will be performed if deemed necessary from the results or if it is has been specifically requested.

A minimum volume of 0.3 ml of blood is required to be able to perform the count accurately.  Paediatric tubes for smaller volumes can be obtained from the department on request.

Requests for ESR, glandular fever screen, sickle screen, malarial parasites and Reticulocyte counts can all be performed on the same specimen sent for FBC.

 

A blood film is performed if there is an unexpected abnormal result reported from the FBC analysis. A film can also be automatically requested if required. The film is a microscopic examination of the blood cells and is made and stained from the FBC sample. The laboratory will report on the size, shape, numbers and maturity of the RBC, WBC and platelets. Any abnormal circulating cells will be reported, including any inclusion bodies and parasites. Grossly abnormal blood films, e.g., a new presentation of leukaemia, will be automatically referred to the Consultant Haematologist for follow up action. 

 

Erythrocyte Sedimentation Rate (ESR)

The ESR is performed using the FBC request, so no further samples are required. A minimum of 1ml of sample is required to perform. The ESR is measured using the Alifax analyser. This gives us a capillary flow value that is consistent with a true ESR value. This allows the ESR to be measured in 2 minutes rather than 1 hour.

The ESR is not a specific test but can be used to indicate changes due to medical conditions or disease states where acute phase reactions occur, e.g., infections, arthritis. It can also be used to monitor treatment of conditions, e.g., in RA.

 

Reticulocyte Count

PURPLE capped Vacutainer tube, EDTA anticoagulant (4 ml)

Reticulocyte cells are immature RBCs that are released earlier by the bone marrow and can therefore be used to assess bone marrow activity. Reticulocyte counts will only be performed where the test would be relevant to the diagnosis or treatment, e.g. evidence of haemorrhage or haemolysis, recent treatment with haematinics, Aplastic anaemia. Reticulocyte counts are performed by the automated cell counter at the same time of the FBC, and reported as both a percentage and an absolute count. Reticulocyte count is performed using the FBC sample therefore, providing a minimum of 1ml of blood is provided for the FBC, no further samples are required. 

 

Glandular Fever screen

PURPLE capped Vacutainer tube, EDTA anticoagulant (4 ml)

The GF screen is also referred to as an infectious mononucleosis screen. This is a viral illness usually affecting adolescents, and manifests as lethargy, swollen glands. The test is based on a latex agglutination against the heterophile antibody produced by the presence of the virus. It is reported as either a positive or negative result, and is performed along with a FBC and blood film. Morphological changes will be present as atypical mononuclear cells seen in the blood film. Glandular fever testing is performed using the FBC sample therefore, providing a minimum of 1ml of blood is provided for the FBC, no further samples are required. 

Sickle Cell Screen

PURPLE capped Vacutainer tube, EDTA anticoagulant (4 ml)

Sickle cell screen are a quick test to determine the presence of Hb S in a patient sample. These are not routinely performed as all requests are firstly sent for HPLC screening (see 6.2). the test will only be performed for urgent theatre cases or for confirmation of Hb S detected by HPLC. The test is based on the solubility of Hb S in a sodium disulphate solution. Normal haemoglobin will dissolve in the solution whereas Hb S will not, with the solution remaining cloudy. The result will either be positive or negative for Hb S but will not be able to distinguish between homozygous and heterozygous patients. 

Sickle Cell Screen is performed using the HPLC sample therefore, providing a minimum of 2ml of blood is provided for HPLC, no further samples are required.

If not, a minimum of 1ml of blood is required. 

 

Malarial Parasites (and other blood parasites)

PURPLE capped Vacutainer tube, EDTA anticoagulant (4 ml)

Malarial parasites are microscopic organisms that have part of its life cycle in the blood stream and cause serious illness with fever. It is possible to view and identify the different stages of the parasite infection in a blood film and therefore report the presence of a malarial parasite infection. It is possible to identify the species of the malarial infection, i.e., Plasmodium Vivax, Falsiparum, Ovale or Malariae.

The department can also perform a cartridge based antibody test, that can be use to confirm the presence of malarial parasites in a blood sample.

Other blood borne parasites, such as microfilaria, trypanosomes, can also be viewed and identified using a blood film made from the FBC sample.   Malarial parasite testing is performed using the FBC sample therefore, providing a minimum of 2ml of blood is provided for the FBC, no further samples are required. 

 

Glucose-6-Phosphate Dihydrogenase (G-6-PD)

PURPLE capped Vacutainer tube, EDTA anticoagulant (4 ml) - A minimum of 2ml of blood is required. 

G-6-PD is a red cell enzyme, a deficiency of which can lead to Haemolytic Anaemia. Haemolysis may be precipitated by the ingestion of oxidant drugs e.g. those used for treatment of malaria (Primaquine, etc). A G-6-PD screen should be performed prior to treatment of malaria with oxidant drugs. The G-6-PD will be reported as normal or deficient.

A G-6-PD assay will be performed on those patients found to be deficient by screening; this is referred to Haematology at Birmingham Heartlands Hospital.

 

Haemoglobinopathy Screening

PURPLE capped Vacutainer tube, EDTA anticoagulant (4 ml) - A minimum of 2ml of blood is required. 

Haemoglobinopathy screening is offered to all antenatal patients, any preoperative patient that may be affected or any patient considered to have an abnormal haemoglobin or thalassaemia. The screening performed using an automated High Pressure Liquid Chromatography (HPLC) method where the red cells are chemically haemolysed to release the haemoglobin. This solution is passed through the HPLC column that separates the different fractions according to charge. Any abnormal haemoglobin fraction is identified. The analyser will identify and measure the clinically significant haemoglobins - Hb A2, F, S, C and D. normal fractions, e.g., Hb A, will also be measured. The analyser will also indicate the presence of Hb E. Any abnormal variants are referred to Sandwell Hospital for confirmation with the exception of HbS. This is confirmed using the sickle screen.  Some Hb variants can only be identified by DNA analysis, and are referred to the reference centre at John Radcliffe Hospital, Oxford. All abnormal variants are reported to the Haemoglobinopathy screening nurse, with any antenatal patients also be referred to the antenatal screening coordinator. The service is designed to provide a counselling service to the patients affected.  

Note

WATCH (antenatal Haemoglobinopathy) screens will only be processed where the sample is accompanied with a completed FOQ form as the test requires patient consent.

Haematinics

Mustard (SST) Vacutainer tube

Haematinic tests are vitamin B12, serum folate, red cell folate and ferritin. They are used as a further investigation to macro- and microcytic anaemias. It is important that specimens for B12 and folate assays are taken prior to the administration of haematinics in the case of anaemic patients, since any underlying deficiency may be masked after treatment. The ferritin is used as an indicator for iron deficiency.  The serum folate is only used as an indicative screen as it is affected by dietary intake. If a low serum folate is measured, a red cell folate will be measured using a FBC sample sent (assuming that a FBC has been requested).

 

 

Coagulation Screen / Coagulation Factor Assays

BLUE capped Vacutainer tube containing liquid Sodium Citrate anticoagulant or in-house paediatric tube. 

Samples should be taken by clean venepuncture and the tube containing the specimen should be mixed thoroughly with the anticoagulant. It is essential that the tubes are filled to the correct level to ensure that the ratio of blood to liquid anticoagulant is correct.

Underfilled samples will result in falsely prolonged coagulation times. Specimens which are received underfilled will be rejected and a second specimen requested. The correct fill level is attained when the Vacutainer tube has been allowed to fill as much as possible before withdrawal from the vein. If manually filled, however, the blood should be to the top of the label on the tube. If the tubes are not mixed thoroughly, clots may form precluding testing.

NB Specimens should NOT be taken from irrigated Venflons or arterial lines as heparin contamination will affect the results, particularly the APTT.

Specimens taken from the site of previous haematomas or obtained with great difficulty may also give inaccurate results.

All specimens for coagulation studies should reach the department as soon as possible after collection. Some coagulation factors are extremely labile and degrade rapidly on storage giving erroneous results. Any sample received older than 4-5 hours may not give valid test results.

Before commencing anticoagulant therapy it is advisable to check that the APTT, INR and platelet counts of the patient are normal. Once therapy has commenced please restrict requests to tests specific to monitoring the particular anticoagulant being administered.

A request for coagulation tests should indicate any anticoagulant therapy within the previous 4 days.

Paediatric tubes are available on request from the department. They are small tubes containing 0.1ml of sodium citrate to which must be added exactly 0.9ml of blood to ensure the correct ratio of anticoagulant to blood. These are normally used for capillary sampling or for cases where there is difficulty in obtaining sufficient quantities of blood, i.e. Neonatal and Paediatric wards.

The department has two automated coagulation analysers that are used to routinely test INR, APTT, Fibrinogen and D-dimer. 

 

Prothrombin time (INR, PT)

 

BLUE capped Vacutainer tube, Sodium Citrate anticoagulant (4 ml)

Samples must be appropriately filled to the black line on the blood tube. 

The test gives an indication of levels of vitamin K dependent coagulation factors, or extrinsic coagulation mechanism, produced in the liver and the patient's result is expressed as a ratio to the time produced for normal subjects.

The INR is used to monitor warfarin therapy as warfarin directly reduces the production of the vitamin K dependent factors.

 

Activated partial thromboplastin time (APTT)

 

BLUE capped Vacutainer tube, Sodium Citrate anticoagulant (4 ml)

Samples must be appropriately filled to the black line on the blood tube. 

The APTT measures the activity of the intrinsic coagulation mechanism and is prolonged in Factor deficiency states, Factors VIII and IX being the most common. It is always reported as a ratio of patient"s result over a normal control value.

The APTT is used to monitor heparin therapy. If the patient is not on a continuous infusion, the timing of the specimen collection should be related to the method and route of heparin therapy. The APTT is not affected by low molecular weight heparin and should not be used to monitor this drug.

It is essential that any relevant history of anticoagulant therapy is included on the request form. Forms indicating heparin therapy will only be tested for APTT, whilst forms indicating Warfarin therapy will only be tested for INR. That is to say, in the interest of economy only tests relevant to monitoring the specific anticoagulant will be performed.

 

Fibrinogen

 

BLUE capped Vacutainer tube, Sodium Citrate anticoagulant (4 ml)

Samples must be appropriately filled to the black line on the blood tube. 

This is the precursor of fibrin which forms the haemostatic plug. Deficiency states of fibrinogen may occur, particularly in disseminated intravascular coagulation. ( DIC ).

 

D-dimer

 

BLUE capped Vacutainer tube, Sodium Citrate anticoagulant (4 ml)

Samples must be appropriately filled to the black line on the blood tube. 

The D-dimer molecule is produced as a breakdown product following the formation of clots. This test can be used as a negative predictor for the occurrence of DVT or PE. It is of little diagnostic value in  post-operative, ante-natal, post-natal or post trauma patients and must be used in conjunction with full assessment of the patient. The D-dimer may also be used in patients with suspected DIC, with the D-dimer being massively elevated.

 

Thrombophilia Screening

 

At least FOUR BLUE capped Vacutainer tubes, Sodium Citrate anticoagulant (4 ml)

Samples must be appropriately filled to the black line on the blood tube. 

This is a group of tests used to determine a patient’s predisposition for a thrombotic event such as PE or DVT, consisting of Protein C, Protein S and Anti-Thrombin III. These are factors involved in the fibrinolytic system, the coagulation cascade inhibitor, in which a deficiency can lead to inappropriate clot formation. These tests are directly affected by anticoagulant drugs and should therefore not be requested during this period of treatment. 

Molecular Thrombophilia Testing

Genetic testing can also be requested to determine if the Factor V Leiden or Prothrombin Gene Variant is present in a patient’s DNA. The presence of these genetic mutations can give a predisposition to thrombotic events. Genetic thrombophilia testing is current sent off site to Haematology at Heartlands Hospital for analysis. 

Lupus Anticoagulant Screening

Lupus anticoagulant screening determines the presence of the lupus inhibitor, an anti-phospholipid antibody which can lead to inappropriate blood clot formation. Lupus anticoagulant testing is currently sent off site to Haematology at Heartlands Hospital for analysis. These tests are directly affected by anticoagulant drugs and should therefore not be requested during this period of treatment. 

Miscellaneous Tests

 

Bone Marrow Aspirate / Bone Marrow Trephine

These are arranged directly by the Consultant Haematologist. Equipment for the biopsy will be provided by the department, but the ward will provide a clean dressing trolley, with a medium sterile dressing pack, a disposal bag and a member of staff to be with the patient.

The bone marrow sample is used to produce smears that can be stained for microscopy examination of the bone marrow cells. Special staining can also be used to determine increased iron deposits. These are used by the Haematologist to diagnose a variety of haematological disorders. 

Bone marrow samples can also be referred to either the Birmingham Medical School for cell marker analysis or the Regional Cytogenetics Laboratory for genetic profiling to further assist the Haematologist when making a diagnosis. 

 


Common referral tests

 

Specialised Coagulation Tests

All specialised coagulation requests are usually referred to University Hospital, Birmingham. This includes specific factor assays, inhibitor screening, von Willebrand disease screening. Any specialised test should be discussed with the department prior to taking the samples to ensure that the arrangements have been made.

 

Anti Factor-Xa

 

BLUE capped Vacutainer tube, Sodium Citrate anticoagulant (4 ml)

Samples must be appropriately filled to the black line on the blood tube. 

This test is used to monitor the use of low molecular weight heparins, such as Clexane or Fragmin. This is particularly important during pregnancy. These samples are referred to Birmingham Women's Hospital, and are analysed on a weekly basis.

 

Erythropoietin

Red capped plain 6 ml sample (serum) containing no additives.

This sample is referred to Clinical Chemistry, Leeds General Infirmary and is a direct measurement of the patient erythropoietin levels. Used primarily to monitor patients on EPO treatments.  

 

Cytogenetic / Molecular genetic Referrals

 These are referred to the West Midlands Regional Genetics Laboratory based at the Birmingham Women's Hospital. There are two different requests forms used depending upon the type of investigation required. The blue cytogenetics referral form for Chromosome analysis and/or FISH Studies i.e. looking for translocations and chromosome re-arrangements. This request requires a Lithium Heparin (Green) sample. This will most commonly be used for Oncology patients. The green molecular genetics form for specific DNA mutations and requires an EDTA sample (Purple)

Conditions for Molecular Genetics Referrals

 

FAMILIAL CANCER DISORDERS

Birt-Hogg-Dubé

Breast / Ovarian Cancer -hereditary

Carney Stratakis syndrome

Familial Adenomatous Polyposis (FAP)

Familial Platelet Disorder (FPD/AML)

Fumarate Hydratase Deficiency

Gastric cancer

Gorlin syndrome (NBCCS)

Hereditary Leiomyomatosis and Renal Cell Cancer

Hereditary Papillary Renal Carcinoma

Lynch syndrome / Hereditary Non-Polyposis Colorectal Cancer (HNPCC)

Medullary Thyroid Carcinoma

Multiple Cutaneous and Uterine Leiomyomatosis

Multiple Endocrine Neoplasia (MEN 2A & 2B)

MET proto-oncogene analysis

MYH-Associated Polyposis

Paraganglioma / Phaechromocytoma

Peutz Jeghers syndrome

PTEN harmartoma tumour syndrome

Renal Cell Cancer

RET proto-oncogene analysis

von-Hippel Lindau (VHL)

INHERITED NON-CANCER DISORDERS

Achondroplasia

Alpha1 antitrypsin deficiency

Alström syndrome

Angelman syndrome

ARC syndrome

Bannayan-Riley-Ruvalcaba syndrome

Becker Muscular Dystrophy (BMD)

Beckwith Wiedemann syndrome (BWS)

Charcot Marie Tooth Neuropathy Type 1A (CMT1A)

Charcot-Marie-Tooth Neuropathy Type 2A (CMT2A)

CHARGE syndrome

Combined Pituitary Hormone Deficiency

Congenital Adrenal Hyperplasia (CAH)

Cowden syndrome

Cystic Fibrosis

Deafness: connexin 26 & connexin 30

Dentatorubral-Pallidoluysian Atrophy (DRPLA)

DIDMOAD

Disomy studies

Duchenne Muscular Dystrophy (DMD)

Escobar syndrome

Fragile X syndrome

Friedreich Ataxia (FRDA)

Haemochromatosis

Hereditary Neuropathy with Liability to Pressure Palsies (HNPP)

Hereditary motor and sensory neuropathy type 1A (HMSN1A)

Hereditary motor and sensory neuropathy type 2A (HMSN2A)

Huntington Disease

Infantile Neuroaxonal Dystrophy (INAD)

Kennedy's disease

Laron syndrome

LEOPARD syndrome

Marfan syndrome

Mitochondrial disorders

Multiple Pterygium syndrome (CHRNG)

Myotonic Dystrophy type 1

Noonan syndrome

Panhypopituitarism

Prader-Willi syndrome

Proteus syndrome

PTEN hamartoma tumour syndrome

Rett syndrome

Sex determination

Silver-Russell syndrome

Smith Lemli Opitz

Sotos syndrome

Spinal and bulbar muscular atrophy (SBMA)

Spinal muscular atrophy (SMA)

Spinocerebellar ataxia (SCA)

Warburg Micro syndrome

Wolfram syndrome

X-inactivation

Zygosity studies