Events on 27 September 2023

vWF Guideline Update

Thrombophilia is defined as hereditary and/or acquired conditions associated with an increased predisposition to thrombosis. The previous British Society for Haematology guideline on thrombophilia testing (2012) focused only heritable thrombophilia testing. The updated guideline published in 2022 (1) has a widened scope to include both heritable and acquired thrombophilia especially antiphospholipid antibodies, paroxysmal nocturnal haemoglobinuria, myeloproliferative neoplasm (MPN) and the presence of a JAK2 mutation in the absence of an MPN phenotype. Disorders such as cancer, inflammatory conditions and obesity are associated with thrombosis through multiple mechanisms, but these are not included in the guideline which focuses only the factors identified from laboratory testing.

The key principle in the guideline is that when clinical utility of testing is not clear, thrombophilia testing is not mandatory, and testing should be done only if the result will alter the management of the patient. These guidelines emphasise the importance of identifying antiphospholipid syndrome and JAK2 +/- MPN phenotype because they have a significant impact on management. The guidelines confirm the limited utility of testing for hereditary thrombophilia testing in venous thromboembolism, arterial thrombosis and recurrent pregnancy loss.

1. Arachchillage, DJ, Mackillop, L, Chandratheva, A, Motawani, J, MacCallum, P, Laffan, M. Thrombophilia testing: A British Society for Haematology guideline. Br J Haematol. 2022; 198: 443– 458. https://doi.org/10.1111/bjh.18239

The effects of long COVID on coagulopathy

Effects of direct thrombin inhibitors [dabigatran/argatroban/bivalirudin] on tests of haemostasis

Meet your Haematology Portfolio examiners

A case study into iron deficiency polycythaemia diagnosis, looking at the pathology and how this relates to the results we see and investigations to confirm diagnosis.

Transient Abnormal Myelopoiesis

Coagulopathy has been shown to play an important role in COVID 19 infection. Reported abnormal coagulation laboratory values in severe COVID-19 are most notably a 3-to-4-fold increase in D-Dimer (Yao et al., 2020).

Several studies showed that elevated D-dimer in COVID-19 patients is associated with higher mortality. A retrospective cohort study carried out by Zhou, et al. (2020) also associated D-Dimer > 1000ng/ml with higher odds of in-patient death.

At the onset of the COVID 19 pandemic, there was no consensus as to how D-Dimer levels should be used for the management of COVID-19 patients. In April 2020, PAHT decided to use a D-Dimer cut-off of 1000 ng/ml to determine anticoagulation dosage. The source of reference used by PAHT in their decision making employed a D-Dimer assay with a cut off value of 500 ng/ml for the exclusion of venous thromboembolism (VTE). This raised an issue as the source of reference used by PAHT at the time employed a D Dimer assay with a cut-off value of 230 ng/ml for the exclusion of VTE. This meant the trust was unable to implement the new COVID 19 care bundle at the time. The haematology laboratory wanting to do whatever possible to assist patient care agreed to change the current D-Dimer methodology immediately to support the trust COVID 19 care bundle.

The verification and implementation of the new D-Dimer assay with cut of 500 ng/ml for the exclusion of VTE was completed within four weeks. A risk assessment and a change control were put in place to ensure users were made aware of the change in cut-off limit.

This verification and implementation of the new assay was possible through the hard and collaborative work of the haematology technical team with shared vision, motivation coupled with team engagement and strong leadership.

The Royal College of Pathologists has led an initiative to improve the transparency and standardise the operation of external quality assurance for providers of clinical diagnostic testing in the UK. This project has resulted in the development of the EQA Governance Framework, bringing together the current system of the National Quality Assurance Advisory Panels and the other stakeholders. Most diagnostic service providers are aware of the Panels, to which the EQA providers report performance concerns relating to UK laboratories, but perhaps are less certain on the criteria for reporting and the involvement of other oversight bodies, e.g., the Medicines and Healthcare Regulatory Agency and the Care Quality Commission.

The EQA Governance Framework has been developed through four separate workstreams. Workstreams 1 and 2 cover the governance and description of the process and have developed a portfolio of documents designed to support a standardised approach to the investigation and resolution of performance concerns with individual laboratories and method related problems.

Fundamental to the management of laboratory performance is the definition of unsatisfactory or poor performance, for qualitative and quantitative testing, in terms applicable to all pathology disciplines, and the action points at which the EQA provider will consider the escalation of a performance concerns to the oversight process. A challenging aspect of the work has been the development of procedures to recognise and manage method-related performance concerns, especially when working with global providers of testing platforms.

This long-term project is intended to strengthen the oversight of diagnostic testing, ensure the sharing of learning points and best practice and benefit patient safety.

Overview of Governance and Escalation of Persistent Poor Performers," we will be discussing the governance structure of EQA in the UK, as well as poor performance and escalation. We will provide three examples and encourage audience participation