Skip to main content
Smaller Larger Print

MENU

Haemophilia Laboratory


The Haemophilia Laboratory provides a comprehensive diagnostic service for inherited and acquired bleeding and thrombotic disorders. The service covers phenotyping for the diagnosis of congenital bleeding and thrombotic disorders, treatment monitoring and inhibitor detection and monitoring, and molecular genetics analysis. The Laboratory also acts as a reference service for other Haemophilia treatment units.


Requests

Requests must be accompanied by a request form and, where appropriate, by an informed consent form.

Samples for platelet aggregometry testing can only be accepted on Mondays–Wednesdays. Please discuss in advance with a haemostasis consultant.


Samples

Samples for Platelet studies (aggregometry, Lumiaggregometry, and platelet nucleotides) and whole blood assays (IMPACT R, PFA-100 and ROTEM) must be hand-delivered to the RFH Special Coagulation laboratory as soon as possible after collection (within two hours of venepuncture).

Pre-examination sample suitability and integrity is important to the final test result that is reported by the laboratory and/ or to the safety of laboratory staff. As a result, the laboratory will reject the specimen and not proceed with analysis of samples if it meets one or more of these criteria:

  • Samples or request forms are received without the minimum essential identification criteria listed in the above table and as a result the details on the sample label cannot be matched with the details on the request form
  • If the sample is unlabelled or mislabelled
  • Blood samples for coagulation testing are filled above the Maximum or below the Minimum fill line etched in the sample tube. A minimum of 90% and maximum of 110% fill is required to have an appropriate ratio of blood to anticoagulant/plasma otherwise the samples are subject to unpredictable dilution and anticoagulation effects which would invalidate the test results.
  • Samples are haemolysed
  • Samples are clotted
  • Sample tubes are used past their expiry date
  • Samples are received leaking and the container is found to be damaged
  • The wrong sample has been received for a given investigation or the sample has been collected in the wrong sample bottles
  • Samples received after 4 hours of collection for clotting screens, APTT, FV and FVIII and after 6 hours of collection for PT/INR
  • Samples received for Specialist Coagulation testing (Bleeding state work ups – Factors II, V, VII, VIII, IX, XI, XII, VWF:Ag, VWF:RCo, VWF:CB, Platelet Aggregation studies, PFA-100, Pro-thrombotic (Thrombophilia testing) – protein C (PC), protein S (PS), Antithrombin (AT), APC-R ratio, other tests plasminogen, antiplasmin, PAI-1, tPA, ROTEM, Thrombin generation, Lupus Anticoagulant, DOAC (Rivaroxabn, Apixaban, Dabigatran, Argatroban levels, LMWH, UFH, Fondaparinux, and Danaparoid levels), which fulfil the above criteria and are received more than 4 hours after collection.
  • Frozen plasma aliquots that have thawed in transit due to incorrect transport conditions (delay in transit, lack of dry ice etc.)
  • Samples for Platelet Studies (Platelet aggregation studies) and ROTEM testing which have been sent via the pneumatic tube. Samples for these tests should be delivered by hand or via the dumb waiter from the Haemophilia and Thrombosis centre
  • Whole citrated blood samples for PAI-1 antigen analysis which are not delivered on crushed ice
  • Samples for genetic testing received without indication that informed consent has been given. In such cases, the laboratory will contact the Requestor informing them that the sample will not be tested unless informed consent is given.


Factors that significantly affect the performance of the examination or interpretation of results

  • Underfilled or Overfilled Citrate tubes so that the ratio of anticoagulant to blood is less or greater than 1:9
  • Clotted samples
  • Haemolysed samples as a result of mixing tubes too vigorously, using the wrong size tube, using the wrong size needle or when the blood is drawn too slowly
  • Heparin contaminated samples (unless for monitoring heparin levels)
  • Out of date citrate tubes
  • Samples for coagulation tests greater than four hours old
  • Samples for INR greater than six hours old
  • Lipaemic samples may interfere with some of the tests carried out.
  • Patients samples with low platelet counts (<80–100 x109/dL) for platelet function investigations

 

Requesting additional tests

Please call the department routine hours for additional tests. Please note that additional tests are dependent during upon sample integrity and suitability for the test:

  • D-dimers within same day
  • INR less than 6 hours
  • All other coagulation tests less than 4 hours